SYSTEMS AND METHODS FOR ACTUATOR AUXILIARY SWITCHING

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is related to U.S. patent application Ser. No. 16/574,806, filed Sep. 18, 2019, which claims priority to provisional U.S. Patent Application No. 62/733,584, filed on Sep. 19, 2018, entitled: “Systems and Methods for Controlling Super Capacitor Charge Voltage to Extend Super Capacitor Life,” the entire contents of both are incorporated by reference herein.

BACKGROUND

The present disclosure relates generally to the field of actuators such as non-spring return actuators and other actuators for use in a building management system (BMS).

A BMS may include a heating, ventilation, and air conditioning (“HVAC”) system, a security system, a lighting system, a fire alerting system, another system that is capable of managing building functions or devices, or any combination thereof. BMS devices may be installed in any environment (e.g., an indoor area or an outdoor area) and the environment may include any number of buildings, spaces, zones, rooms, or areas. A BMS may include a variety of devices (e.g., HVAC devices, controllers, chillers, fans, sensors, etc.) configured to facilitate monitoring and controlling the building space. Actuators are used with HAVC equipment and other BMS equipment to provide mechanical motion. Actuators can include spring return actuators and non-spring return actuators (e.g., capacitive powered return actuators and non-return actuators). A return actuator (e.g., a spring return and capacitive powered actuator) are configured to perform a failsafe operation where the actuator returns to a pre-set home position when power is removed from the actuator.

Actuators can include mechanically actuated auxiliary switches. Auxiliary switches of an actuator can server various purposes. For example, an auxiliary switch can be used for contact closure at specific points along the actuator stroke. Actuators can be configured to include one or two mechanically actuated auxiliary switches. Mechanical actuated auxiliary switches add to the cost of the actuator, can be difficult to adjust to new set points, require a new tooled parts for each actuator design, require extensive development testing for each new actuator design, and have a large footprint.

SUMMARY

Some embodiments relate to an actuator in a heating, ventilating or air conditioning (HVAC) system. The actuator includes a motor, a drive mechanism driven by the motor and configured to move an HVAC component among positions, a latch relay auxiliary switch, and a controller. The controller is configured to provide a control signal to the latch relay auxiliary switch to open and close contacts of the latch relay auxiliary switch and operate the motor to move the HVAC component based on a determined position.

In some embodiments, the control signal is provided in response to a position of the drive mechanism. In some embodiments, the actuator also includes a non-interruptible power supply coupled to the controller. The controller is configured to provide the control signal and operate the motor while powered by the non-interruptible power supply in event of a power failure. In some embodiments, the non-interruptible power supply comprises a capacitor configured to store an amount of energy to provide the control signal and operate the motor while powered by the non-interruptible power supply in event of the power failure.

In some embodiments, the actuator is a linear or rotary actuator. In some embodiments, the latch relay auxiliary switch is provided within a housing of the actuator. In some embodiments, the latch relay auxiliary switch is configured to provide power to an HVAC device.

Some embodiments relate to an actuator system including a drive mechanism configured to move an HVAC component, a latch relay auxiliary switch, and a controller. The controller is configured to provide a relay control signal to the latch relay auxiliary switch to open and close contacts of the latch relay auxiliary switch. The controller is also configured to provide a drive control signal move the HVAC component based on a determined position of the drive mechanism.

In some embodiments, the actuator system also includes another latch relay auxiliary switch. The controller is configured to provide another relay control signal to the another latch relay auxiliary switch to open and close contacts of the another latch relay auxiliary switch.

In some embodiments, actuator system also includes a non-interruptible power supply coupled to the controller. The controller is configured to provide the relay control signal and the drive control signal while powered by the non-interruptible power supply in event of a power failure. In some embodiments, the non-interruptible power supply includes a capacitor configured to store an amount of energy to provide the relay control signal while powered by the non-interruptible power supply in event of the power failure.

In some embodiments, the latch relay auxiliary switch is an electromagnetic relay. In some embodiments, the latch relay auxiliary switch comprises normally open and normally closed contact. In some embodiments, the controller is configured to receive set points for actuating the latch relay auxiliary switch. The set points are associated with a position of the drive mechanism. In some embodiments, the set points are provided by near field communication from a user device to the controller. In some embodiments, the set points are provided by a remote server.

Some embodiments relate to a method of controlling a heating, ventilating or air conditioning (HVAC) actuator. The HVAC actuator includes a motor, a gear driven by the motor and coupled to a movable HVAC component, and an auxiliary switch. The method includes operating the motor to change a position of the movable HVAC component in response a determined position of the gear or the motor using an electronic actuator control signal, and operating the auxiliary switch in response the determined position using an electronic switch control signal. The auxiliary switch is a latch relay switch.

In some embodiments, the determined position is provided in response to a position signal from a position sensor. In some embodiments, the operating steps are performed using power stored in a capacitor provided within the HVAC actuator. In some embodiments, the method also includes charging the capacitor to an amount of energy to provide the electronic switch control signal and operate the motor to move the movable HVAC component to a default position.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects, aspects, features, and advantages of the disclosure will become more apparent and better understood by referring to the detailed description taken in conjunction with the accompanying drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.

FIG. 1 is a drawing of a building equipped with a HVAC system, according to some embodiments.

FIG. 2 is a block diagram of a waterside system which may be used to serve the building of FIG. 1, according to some embodiments.

FIG. 3 is a block diagram of an airside system which may be used to serve the building of FIG. 1, according to some embodiments.

FIG. 4 is a block diagram of a building management system (BMS) which may be used to monitor and control the building of FIG. 1, according to some embodiments.

FIG. 5 is a block diagram of an actuator that includes an uninterruptable power source and non-mechanically actuated auxiliary switches according to some embodiments.

FIG. 6 is a block diagram of a non-spring return actuator that includes non-mechanical actuated auxiliary switches, according to some embodiments, according to some embodiments.

DETAILED DESCRIPTION

Overview

Uninterruptable power supply actuators (e.g., capacitive return actuators) and non-return actuators in HVAC applications are configured to provide auxiliary switching capabilities without using mechanical actuated switches in some embodiments. An interruptible power supply has enough stored energy for the actuator to drive a component to a normal position (e.g., home position) and control the auxiliary switch when power is removed in some embodiments. The actuators can advantageously use latch relay switches or pulse relay switches as non-mechanically actuated auxiliary switches under control of the control unit of the actuator in some embodiments. A latch relay switch refers to an electromechanical or electromagnetic switch that can maintain a position without a continuous electrical input including but not limited to a bistable switches, keep switches, or stay relay switches in some embodiments. A latch relay switch can maintain its switch state when power is removed. A pulse relay switch is a type of relay switch that turns on or off for a specific amount of time in some embodiments.

The latch relay switches and pulse relay switches can have normally closed and/or normally open contacts. In some embodiments, the latch switches and pulse relay switches have three contacts, common, normally open and normally closed and a control connection. A cable or a terminal block integrated with the relay switch can be used to make connections to the control connection and/or contacts in some embodiments. The contacts are isolated from mechanical operation of the actuator and electromagnetically isolated from the actuator electronics in some embodiments.

In some embodiments, one or more latch relay switches or pulse relay switches are included with an actuator system to provide binary feedback that the actuator (driving a damper or valve) has reached a specific point of travel. The latch relay switches are configured to have contacts that can carry a 3-5 amp current so that another device can be powered through the latch relay switch (e.g., the latch relay switch can provide or a power control signal larger than signal grade currents). For example, the latch relay switch can be used to power a fan when the actuator has driven the damper blades to a position (e.g. 40% open). By using the switch instead of just a delayed timed start, positional physical feedback that the actuator has actually moved the specific rotation is provided. The positional feedback reduces the risk of running a fan into a closed duct potentially causing high pressures and can provide binary feedback into a control system which in turn powers the fan.

Using sensed position signals, pulse relay switches and latch relay switches can be used to provide programmable position feedback including end stop feedback. For example, the main control unit (MCU) of the actuator activates the latch relay switch or pulse relay switches at user setpoints provided via a user interface or remote programming.

In some embodiments, systems and methods of auxiliary switching are provided on a failsafe device with an uninterruptable power supply. The latch relay switches and pulse relay switches continue to function on a return to normal cycle when power is removed using the uninterruptable power supply. A main control unit of the actuator powered by the uninterruptable power supply activates the pulse relay switches or the latch relay switches when input power is lost. Accordingly, the failsafe device (e.g., an actuator, etc.) may be configured to set auxiliary switch state when power is lost using power from the uninterruptable power source. The switch state is maintained independent of power loss and is dependent of actuator output position. In some embodiments, enough energy is stored to activate the latch relay when the setpoint is reached during a fail safe operation (e.g., a capacitance return operation). Additional energy can be provided by additional capacitors in some embodiments.

In some embodiments, a single switch module is used across an entire actuator portfolio of products, thereby saving design costs. A latch relay switch can be used in all actuators sharing common parts, thereby increasing volumetric efficiencies because a mechanical link to the auxiliary switch is not required,

Building HVAC Systems and Building Management Systems

Referring now to FIGS. 1-4, several building management systems (BMS) and HVAC systems in which the systems and methods of the present disclosure may be implemented are shown, according to some embodiments. In brief overview, FIG. 1 shows a building 10 equipped with a HVAC system 100. FIG. 2 is a block diagram of a waterside system 200 which may be used to serve building 10. FIG. 3 is a block diagram of an airside system 300 which may be used to serve building 10. FIG. 4 is a block diagram of a BMS which may be used to monitor and control building 10.

Building and HVAC System

Referring particularly to FIG. 1, a perspective view of a building 10 is shown. Building 10 is served by a BMS. A BMS is, in general, a system of devices configured to control, monitor, and manage equipment in or around a building or building area. A BMS may include, for example, a HVAC system, a security system, a lighting system, a fire alerting system, any other system that is capable of managing building functions or devices, or any combination thereof.

The BMS that serves building 10 includes a HVAC system 100. HVAC system 100 may include a plurality of HVAC devices (e.g., heaters, chillers, air handling units, pumps, fans, thermal energy storage, etc.) configured to provide heating, cooling, ventilation, or other services for building 10. For example, HVAC system 100 is shown to include a waterside system 120 and an airside system 130. Waterside system 120 may provide a heated or chilled fluid to an air handling unit of airside system 130. Airside system 130 may use the heated or chilled fluid to heat or cool an airflow provided to building 10. An exemplary waterside system and airside system which may be used in HVAC system 100 are described in greater detail with reference to FIGS. 2-3.

HVAC system 100 is shown to include a chiller 102, a boiler 104, and a rooftop air handling unit (AHU) 106. Waterside system 120 may use boiler 104 and chiller 102 to heat or cool a working fluid (e.g., water, glycol, etc.) and may circulate the working fluid to AHU 106. In various embodiments, the HVAC devices of waterside system 120 may be located in or around building 10 (as shown in FIG. 1) or at an offsite location such as a central plant (e.g., a chiller plant, a steam plant, a heat plant, etc.). The working fluid may be heated in boiler 104 or cooled in chiller 102, depending on whether heating or cooling is required in building 10. Boiler 104 may add heat to the circulated fluid, for example, by burning a combustible material (e.g., natural gas) or using an electric heating element. Chiller 102 may place the circulated fluid in a heat exchange relationship with another fluid (e.g., a refrigerant) in a heat exchanger (e.g., an evaporator) to absorb heat from the circulated fluid. The working fluid from chiller 102 and/or boiler 104 may be transported to AHU 106 via piping 108.

AHU 106 may place the working fluid in a heat exchange relationship with an airflow passing through AHU 106 (e.g., via one or more stages of cooling coils and/or heating coils). The airflow may be, for example, outside air, return air from within building 10, or a combination of both. AHU 106 may transfer heat between the airflow and the working fluid to provide heating or cooling for the airflow. For example, AHU 106 may include one or more fans or blowers configured to pass the airflow over or through a heat exchanger including the working fluid. The working fluid may then return to chiller 102 or boiler 104 via piping 110.

Airside system 130 may deliver the airflow supplied by AHU 106 (i.e., the supply airflow) to building 10 via air supply ducts 112 and may provide return air from building 10 to AHU 106 via air return ducts 114. In some embodiments, airside system 130 includes multiple variable air volume (VAV) units 116. For example, airside system 130 is shown to include a separate VAV unit 116 on each floor or zone of building 10. VAV units 116 may include dampers or other flow control elements that may be operated to control an amount of the supply airflow provided to individual zones of building 10. In other embodiments, airside system 130 delivers the supply airflow into one or more zones of building 10 (e.g., via supply ducts 112) without using intermediate VAV units 116 or other flow control elements. AHU 106 may include various sensors (e.g., temperature sensors, pressure sensors, etc.) configured to measure attributes of the supply airflow. AHU 106 may receive input from sensors located within AHU 106 and/or within the building zone and may adjust the flow rate, temperature, or other attributes of the supply airflow through AHU 106 to achieve set point conditions for the building zone.

Waterside System

Referring now to FIG. 2, a block diagram of a waterside system 200 is shown, according to some embodiments. In various embodiments, waterside system 200 may supplement or replace waterside system 120 in HVAC system 100 or may be implemented separate from HVAC system 100. When implemented in HVAC system 100, waterside system 200 may include a subset of the HVAC devices in HVAC system 100 (e.g., boiler 104, chiller 102, pumps, valves, etc.) and may operate to supply a heated or chilled fluid to AHU 106. The HVAC devices of waterside system 200 may be located within building 10 (e.g., as components of waterside system 120) or at an offsite location such as a central plant.

In FIG. 2, waterside system 200 is shown as a central plant having a plurality of subplants 202-212. Subplants 202-212 are shown to include a heater subplant 202, a heat recovery chiller subplant 204, a chiller subplant 206, a cooling tower subplant 208, a hot thermal energy storage (TES) subplant 210, and a cold thermal energy storage (TES) subplant 212. Subplants 202-212 consume resources (e.g., water, natural gas, electricity, etc.) from utilities to serve thermal energy loads (e.g., hot water, cold water, heating, cooling, etc.) of a building or campus. For example, heater subplant 202 may be configured to heat water in a hot water loop 214 that circulates the hot water between heater subplant 202 and building 10. Chiller subplant 206 may be configured to chill water in a cold water loop 216 that circulates the cold water between chiller subplant 206 building 10. Heat recovery chiller subplant 204 may be configured to transfer heat from cold water loop 216 to hot water loop 214 to provide additional heating for the hot water and additional cooling for the cold water. Condenser water loop 218 may absorb heat from the cold water in chiller subplant 206 and reject the absorbed heat in cooling tower subplant 208 or transfer the absorbed heat to hot water loop 214. Hot TES subplant 210 and cold TES subplant 212 may store hot and cold thermal energy, respectively, for subsequent use.

Hot water loop 214 and cold water loop 216 may deliver the heated and/or chilled water to air handlers located on the rooftop of building 10 (e.g., AHU 106) or to individual floors or zones of building 10 (e.g., VAV units 116). The air handlers push air past heat exchangers (e.g., heating coils or cooling coils) through which the water flows to provide heating or cooling for the air. The heated or cooled air may be delivered to individual zones of building 10 to serve thermal energy loads of building 10. The water then returns to subplants 202-212 to receive further heating or cooling.

Although subplants 202-212 are shown and described as heating and cooling water for circulation to a building, it is understood that any other type of working fluid (e.g., glycol, CO2, etc.) may be used in place of or in addition to water to serve thermal energy loads. In other embodiments, subplants 202-212 may provide heating and/or cooling directly to the building or campus without requiring an intermediate heat transfer fluid. These and other variations to waterside system 200 are within the teachings of the present disclosure.

Each of subplants 202-212 may include a variety of equipment configured to facilitate the functions of the subplant. For example, heater subplant 202 is shown to include a plurality of heating elements 220 (e.g., boilers, electric heaters, etc.) configured to add heat to the hot water in hot water loop 214. Heater subplant 202 is also shown to include several pumps 222 and 224 configured to circulate the hot water in hot water loop 214 and to control the flow rate of the hot water through individual heating elements 220. Chiller subplant 206 is shown to include a plurality of chillers 232 configured to remove heat from the cold water in cold water loop 216. Chiller subplant 206 is also shown to include several pumps 234 and 236 configured to circulate the cold water in cold water loop 216 and to control the flow rate of the cold water through individual chillers 232.

Heat recovery chiller subplant 204 is shown to include a plurality of heat recovery heat exchangers 226 (e.g., refrigeration circuits) configured to transfer heat from cold water loop 216 to hot water loop 214. Heat recovery chiller subplant 204 is also shown to include several pumps 228 and 230 configured to circulate the hot water and/or cold water through heat recovery heat exchangers 226 and to control the flow rate of the water through individual heat recovery heat exchangers 226. Cooling tower subplant 208 is shown to include a plurality of cooling towers 238 configured to remove heat from the condenser water in condenser water loop 218. Cooling tower subplant 208 is also shown to include several pumps 240 configured to circulate the condenser water in condenser water loop 218 and to control the flow rate of the condenser water through individual cooling towers 238.

Hot TES subplant 210 is shown to include a hot TES tank 242 configured to store the hot water for later use. Hot TES subplant 210 may also include one or more pumps or valves configured to control the flow rate of the hot water into or out of hot TES tank 242. Cold TES subplant 212 is shown to include cold TES tanks 244 configured to store the cold water for later use. Cold TES subplant 212 may also include one or more pumps or valves configured to control the flow rate of the cold water into or out of cold TES tanks 244.

In some embodiments, one or more of the pumps in waterside system 200 (e.g., pumps 222, 224, 228, 230, 234, 236, and/or 240) or pipelines in waterside system 200 include an isolation valve associated therewith. Isolation valves may be integrated with the pumps or positioned upstream or downstream of the pumps to control the fluid flows in waterside system 200. In various embodiments, waterside system 200 may include more, fewer, or different types of devices and/or subplants based on the particular configuration of waterside system 200 and the types of loads served by waterside system 200.

Airside System

Referring now to FIG. 3, a block diagram of an airside system 300 is shown, according to some embodiments. In various embodiments, airside system 300 may supplement or replace airside system 130 in HVAC system 100 or may be implemented separate from HVAC system 100. When implemented in HVAC system 100, airside system 300 may include a subset of the HVAC devices in HVAC system 100 (e.g., AHU 106, VAV units 116, ducts 112-114, fans, dampers, etc.) and may be located in or around building 10. Airside system 300 may operate to heat or cool an airflow provided to building 10 using a heated or chilled fluid provided by waterside system 200.

In FIG. 3, airside system 300 is shown to include an economizer-type air handling unit (AHU) 302. Economizer-type AHUs vary the amount of outside air and return air used by the air handling unit for heating or cooling. For example, AHU 302 may receive return air 304 from building zone 306 via return air duct 308 and may deliver supply air 310 to building zone 306 via supply air duct 312. In some embodiments, AHU 302 is a rooftop unit located on the roof of building 10 (e.g., AHU 106 as shown in FIG. 1) or otherwise positioned to receive both return air 304 and outside air 314. AHU 302 may be configured to operate exhaust air damper 316, mixing damper 318, and outside air damper 320 to control an amount of outside air 314 and return air 304 that combine to form supply air 310. Any return air 304 that does not pass through mixing damper 318 may be exhausted from AHU 302 through exhaust damper 316 as exhaust air 322.

Each of dampers 316-320 may be operated by an actuator which may use the auxiliary switching techniques described herein. For example, exhaust air damper 316 may be operated by actuator 324, mixing damper 318 may be operated by actuator 326, and outside air damper 320 may be operated by actuator 328. Actuators 324-328 may communicate with an AHU controller 330 via a communications link 332. Actuators 324-328 may receive control signals from AHU controller 330 and may provide feedback signals to AHU controller 330. Feedback signals may include, for example, an indication of a current actuator or damper position, an amount of torque or force exerted by the actuator, diagnostic information (e.g., results of diagnostic tests performed by actuators 324-328), status information, commissioning information, configuration settings, calibration data, and/or other types of information or data that may be collected, stored, or used by actuators 324-328. AHU controller 330 may be an economizer controller configured to use one or more control algorithms (e.g., state-based algorithms, extremum seeking control (ESC) algorithms, proportional-integral (PI) control algorithms, proportional-integral-derivative (PID) control algorithms, model predictive control (MPC) algorithms, feedback control algorithms, etc.) to control actuators 324-328.

Still referring to FIG. 3, AHU 302 is shown to include a cooling coil 334, a heating coil 336, and a fan 338 positioned within supply air duct 312. Fan 338 may be configured to force supply air 310 through cooling coil 334 and/or heating coil 336 and provide supply air 310 to building zone 306. AHU controller 330 may communicate with fan 338 via communications link 340 to control a flow rate of supply air 310. In some embodiments, AHU controller 330 controls an amount of heating or cooling applied to supply air 310 by modulating a speed of fan 338.

Cooling coil 334 may receive a chilled fluid from waterside system 200 (e.g., from cold water loop 216) via piping 342 and may return the chilled fluid to waterside system 200 via piping 344. Valve 346 may be positioned along piping 342 or piping 344 to control a flow rate of the chilled fluid through cooling coil 334. In some embodiments, cooling coil 334 includes multiple stages of cooling coils that may be independently activated and deactivated (e.g., by AHU controller 330, by BMS controller 366, etc.) to modulate an amount of cooling applied to supply air 310.

Heating coil 336 may receive a heated fluid from waterside system 200 (e.g., from hot water loop 214) via piping 348 and may return the heated fluid to waterside system 200 via piping 350. Valve 352 may be positioned along piping 348 or piping 350 to control a flow rate of the heated fluid through heating coil 336. In some embodiments, heating coil 336 includes multiple stages of heating coils that may be independently activated and deactivated (e.g., by AHU controller 330, by BMS controller 366, etc.) to modulate an amount of heating applied to supply air 310.

Each of valves 346 and 352 may be controlled by an actuator which may use the auxiliary switching techniques described herein. For example, valve 346 may be controlled by actuator 354 and valve 352 may be controlled by actuator 356. Actuators 354-356 may communicate with AHU controller 330 via communications links 358-360. Actuators 354-356 may receive control signals from AHU controller 330 and may provide feedback signals to controller 330. In some embodiments, AHU controller 330 receives a measurement of the supply air temperature from a temperature sensor 362 positioned in supply air duct 312 (e.g., downstream of cooling coil 334 and/or heating coil 336). AHU controller 330 may also receive a measurement of the temperature of building zone 306 from a temperature sensor 364 located in building zone 306.

In some embodiments, AHU controller 330 operates valves 346 and 352 via actuators 354-356 to modulate an amount of heating or cooling provided to supply air 310 (e.g., to achieve a setpoint temperature for supply air 310 or to maintain the temperature of supply air 310 within a setpoint temperature range). The positions of valves 346 and 352 affect the amount of heating or cooling provided to supply air 310 by cooling coil 334 or heating coil 336 and may correlate with the amount of energy consumed to achieve a desired supply air temperature. AHU controller 330 may control the temperature of supply air 310 and/or building zone 306 by activating or deactivating coils 334-336, adjusting a speed of fan 338, or a combination of both.

Still referring to FIG. 3, airside system 300 is shown to include a building management system (BMS) controller 366 and a client device 368. BMS controller 366 may include one or more computer systems (e.g., servers, supervisory controllers, subsystem controllers, etc.) that serve as system level controllers, application or data servers, head nodes, or supervisory controllers for airside system 300, waterside system 200, HVAC system 100, and/or other controllable systems that serve building 10. BMS controller 366 may communicate with multiple downstream building systems or subsystems (e.g., HVAC system 100, a security system, a lighting system, waterside system 200, etc.) via a communications link 370 according to like or disparate protocols (e.g., LON, BACnet, etc.). In various embodiments, AHU controller 330 and BMS controller 366 may be separate (as shown in FIG. 3) or integrated. In an integrated implementation, AHU controller 330 may be a software module configured for execution by a processor of BMS controller 366.

In some embodiments, AHU controller 330 receives information from BMS controller 366 (e.g., commands, setpoints, operating boundaries, etc.) and provides information to BMS controller 366 (e.g., temperature measurements, valve or actuator positions, operating statuses, diagnostics, etc.). For example, AHU controller 330 may provide BMS controller 366 with temperature measurements from temperature sensors 362-364, equipment on/off states, equipment operating capacities, and/or any other information that may be used by BMS controller 366 to monitor or control a variable state or condition within building zone 306.

Client device 368 may include one or more human-machine interfaces or client interfaces (e.g., graphical user interfaces, reporting interfaces, text-based computer interfaces, client-facing web services, web servers that provide pages to web clients, etc.) for controlling, viewing, or otherwise interacting with HVAC system 100, its subsystems, and/or devices. Client device 368 may be a computer workstation, a client terminal, a remote or local interface, or any other type of user interface device. Client device 368 may be a stationary terminal or a mobile device. For example, client device 368 may be a desktop computer, a computer server with a user interface, a laptop computer, a tablet, a smartphone, a PDA, or any other type of mobile or non-mobile device. Client device 368 may communicate with BMS controller 366 and/or AHU controller 330 via communications link 372. Client device 368 can be utilized to provide set points for the auxiliary switching techniques described herein. Referring now to FIGS. 5-7, an actuator 500 for use in a HVAC system is shown, according to an exemplary embodiment. In some implementations, actuator 500 may be used in HVAC system 100, waterside system 200, airside system 300, or BMS 400, as described with reference to FIGS. 1-4. For example, actuator 500 is a damper actuator, a valve actuator, a fan actuator, a pump actuator, fire safety actuator, or any other type of actuator that can be used in a HVAC system or BMS. In various embodiments, actuator 500 is a linear actuator (e.g., a linear proportional actuator), a non-linear actuator, a rotational actuator, a spring return actuator, or a non-spring return actuator.

Building Management Systems

Referring now to FIG. 4, a block diagram of a building management system (BMS) 400 is shown, according to some embodiments. BMS 400 may be implemented in building 10 to automatically monitor and control various building functions. BMS 400 is shown to include BMS controller 366 and a plurality of building subsystems 428. Building subsystems 428 are shown to include a building electrical subsystem 434, an information communication technology (ICT) subsystem 436, a security subsystem 438, a HVAC subsystem 440, a lighting subsystem 442, a lift/escalators subsystem 432, and a fire safety subsystem 430. In various embodiments, building subsystems 428 may include fewer, additional, or alternative subsystems. For example, building subsystems 428 may also or alternatively include a refrigeration subsystem, an advertising or signage subsystem, a cooking subsystem, a vending subsystem, a printer or copy service subsystem, or any other type of building subsystem that uses controllable equipment and/or sensors to monitor or control building 10. In some embodiments, building subsystems 428 include waterside system 200 and/or airside system 300, as described with reference to FIGS. 2-3.

Each of building subsystems 428 may include any number of devices, controllers, and connections for completing its individual functions and control activities. HVAC subsystem 440 may include many of the same components as HVAC system 100, as described with reference to FIGS. 1-3. For example, HVAC subsystem 440 may include a chiller, a boiler, any number of air handling units, economizers, field controllers, supervisory controllers, actuators, temperature sensors, and other devices for controlling the temperature, humidity, airflow, or other variable conditions within building 10. Lighting subsystem 442 may include any number of light fixtures, ballasts, lighting sensors, dimmers, or other devices configured to controllably adjust the amount of light provided to a building space. Security subsystem 438 may include occupancy sensors, video surveillance cameras, digital video recorders, video processing servers, intrusion detection devices, access control devices and servers, or other security-related devices.

Still referring to FIG. 4, BMS controller 366 is shown to include a communications interface 407 and a BMS interface 409. Interface 407 may facilitate communications between BMS controller 366 and external applications (e.g., monitoring and reporting applications 422, enterprise control applications 426, remote systems and applications 444, applications residing on client devices 448, etc.) for allowing user control, monitoring, and adjustment to BMS controller 366 and/or subsystems 428. Interface 407 may also facilitate communications between BMS controller 366 and client devices 448. BMS interface 409 may facilitate communications between BMS controller 366 and building subsystems 428 (e.g., HVAC, lighting security, lifts, power distribution, business, etc.).

Interfaces 407, 409 may be or include wired or wireless communications interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals, etc.) for conducting data communications with building subsystems 428 or other external systems or devices. In various embodiments, communications via interfaces 407, 409 may be direct (e.g., local wired or wireless communications) or via a communications network 446 (e.g., a WAN, the Internet, a cellular network, etc.). For example, interfaces 407, 409 may include an Ethernet card and port for sending and receiving data via an Ethernet-based communications link or network. In another example, interfaces 407, 409 may include a Wi-Fi transceiver for communicating via a wireless communications network. In another example, one or both of interfaces 407, 409 may include cellular or mobile phone communications transceivers. In one embodiment, communications interface 407 is a power line communications interface and BMS interface 409 is an Ethernet interface. In other embodiments, both communications interface 407 and BMS interface 409 are Ethernet interfaces or are the same Ethernet interface.

Still referring to FIG. 4, BMS controller 366 is shown to include a processing circuit 404 including a processor 406 and memory 408. Processing circuit 404 may be communicably connected to BMS interface 409 and/or communications interface 407 such that processing circuit 404 and the various components thereof may send and receive data via interfaces 407, 409. Processor 406 may be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable electronic processing components.

Memory 408 (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage, etc.) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present application. Memory 408 may be or include volatile memory or non-volatile memory. Memory 408 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present application. According to some embodiments, memory 408 is communicably connected to processor 406 via processing circuit 404 and includes computer code for executing (e.g., by processing circuit 404 and/or processor 406) one or more processes described herein.

In some embodiments, BMS controller 366 is implemented within a single computer (e.g., one server, one housing, etc.). In various other embodiments BMS controller 366 may be distributed across multiple servers or computers (e.g., that may exist in distributed locations). Further, while FIG. 4 shows applications 422 and 426 as existing outside of BMS controller 366, in some embodiments, applications 422 and 426 may be hosted within BMS controller 366 (e.g., within memory 408).

Still referring to FIG. 4, memory 408 is shown to include an enterprise integration layer 410, an automated measurement and validation (AM&V) layer 412, a demand response (DR) layer 414, a fault detection and diagnostics (FDD) layer 416, an integrated control layer 418, and a building subsystem integration later 420. Layers 410-420 may be configured to receive inputs from building subsystems 428 and other data sources, determine optimal control actions for building subsystems 428 based on the inputs, generate control signals based on the optimal control actions, and provide the generated control signals to building subsystems 428. The following paragraphs describe some of the general functions performed by each of layers 410-420 in BMS 400.

Enterprise integration layer 410 may be configured to serve clients or local applications with information and services to support a variety of enterprise-level applications. For example, enterprise control applications 426 may be configured to provide subsystem-spanning control to a graphical user interface (GUI) or to any number of enterprise-level business applications (e.g., accounting systems, user identification systems, etc.). Enterprise control applications 426 may also or alternatively be configured to provide configuration GUIs for configuring BMS controller 366. In yet other embodiments, enterprise control applications 426 may work with layers 410-420 to optimize building performance (e.g., efficiency, energy use, comfort, or safety) based on inputs received at interface 407 and/or BMS interface 409.

Building subsystem integration layer 420 may be configured to manage communications between BMS controller 366 and building subsystems 428. For example, building subsystem integration layer 420 may receive sensor data and input signals from building subsystems 428 and provide output data and control signals to building subsystems 428. Building subsystem integration layer 420 may also be configured to manage communications between building subsystems 428. Building subsystem integration layer 420 translate communications (e.g., sensor data, input signals, output signals, etc.) across a plurality of multi-vendor/multi-protocol systems.

Demand response layer 414 may be configured to optimize resource usage (e.g., electricity use, natural gas use, water use, etc.) and/or the monetary cost of such resource usage in response to satisfy the demand of building 10. The optimization may be based on time-of-use prices, curtailment signals, energy availability, or other data received from utility providers, distributed energy generation systems 424, from energy storage 427 (e.g., hot TES 242, cold TES 244, etc.), or from other sources. Demand response layer 414 may receive inputs from other layers of BMS controller 366 (e.g., building subsystem integration layer 420, integrated control layer 418, etc.). The inputs received from other layers may include environmental or sensor inputs such as temperature, carbon dioxide levels, relative humidity levels, air quality sensor outputs, occupancy sensor outputs, room schedules, and the like. The inputs may also include inputs such as electrical use (e.g., expressed in kWh), thermal load measurements, pricing information, projected pricing, smoothed pricing, curtailment signals from utilities, and the like.

According to some embodiments, demand response layer 414 includes control logic for responding to the data and signals it receives. These responses may include communicating with the control algorithms in integrated control layer 418, changing control strategies, changing setpoints, or activating/deactivating building equipment or subsystems in a controlled manner. Demand response layer 414 may also include control logic configured to determine when to utilize stored energy. For example, demand response layer 414 may determine to begin using energy from energy storage 427 just prior to the beginning of a peak use hour.

In some embodiments, demand response layer 414 includes a control module configured to actively initiate control actions (e.g., automatically changing setpoints) which minimize energy costs based on one or more inputs representative of or based on demand (e.g., price, a curtailment signal, a demand level, etc.). In some embodiments, demand response layer 414 uses equipment models to determine an optimal set of control actions. The equipment models may include, for example, thermodynamic models describing the inputs, outputs, and/or functions performed by various sets of building equipment. Equipment models may represent collections of building equipment (e.g., subplants, chiller arrays, etc.) or individual devices (e.g., individual chillers, heaters, pumps, etc.).

Demand response layer 414 may further include or draw upon one or more demand response policy definitions (e.g., databases, XML files, etc.). The policy definitions may be edited or adjusted by a user (e.g., via a graphical user interface) so that the control actions initiated in response to demand inputs may be tailored for the user's application, desired comfort level, particular building equipment, or based on other concerns. For example, the demand response policy definitions may specify which equipment may be turned on or off in response to particular demand inputs, how long a system or piece of equipment should be turned off, what setpoints may be changed, what the allowable set point adjustment range is, how long to hold a high demand setpoint before returning to a normally scheduled setpoint, how close to approach capacity limits, which equipment modes to utilize, the energy transfer rates (e.g., the maximum rate, an alarm rate, other rate boundary information, etc.) into and out of energy storage devices (e.g., thermal storage tanks, battery banks, etc.), and when to dispatch on-site generation of energy (e.g., via fuel cells, a motor generator set, etc.).

Integrated control layer 418 may be configured to use the data input or output of building subsystem integration layer 420 and/or demand response later 414 to make control decisions. Due to the subsystem integration provided by building subsystem integration layer 420, integrated control layer 418 may integrate control activities of the subsystems 428 such that the subsystems 428 behave as a single integrated supersystem. In some embodiments, integrated control layer 418 includes control logic that uses inputs and outputs from a plurality of building subsystems to provide greater comfort and energy savings relative to the comfort and energy savings that separate subsystems could provide alone. For example, integrated control layer 418 may be configured to use an input from a first subsystem to make an energy-saving control decision for a second subsystem. Results of these decisions may be communicated back to building subsystem integration layer 420.

Integrated control layer 418 is shown to be logically below demand response layer 414. Integrated control layer 418 may be configured to enhance the effectiveness of demand response layer 414 by enabling building subsystems 428 and their respective control loops to be controlled in coordination with demand response layer 414. This configuration may advantageously reduce disruptive demand response behavior relative to conventional systems. For example, integrated control layer 418 may be configured to assure that a demand response-driven upward adjustment to the setpoint for chilled water temperature (or another component that directly or indirectly affects temperature) does not result in an increase in fan energy (or other energy used to cool a space) that would result in greater total building energy use than was saved at the chiller.

Integrated control layer 418 may be configured to provide feedback to demand response layer 414 so that demand response layer 414 checks that constraints (e.g., temperature, lighting levels, etc.) are properly maintained even while demanded load shedding is in progress. The constraints may also include setpoint or sensed boundaries relating to safety, equipment operating limits and performance, comfort, fire codes, electrical codes, energy codes, and the like. Integrated control layer 418 is also logically below fault detection and diagnostics layer 416 and automated measurement and validation layer 412. Integrated control layer 418 may be configured to provide calculated inputs (e.g., aggregations) to these higher levels based on outputs from more than one building subsystem.

Automated measurement and validation (AM&V) layer 412 may be configured to verify whether control strategies commanded by integrated control layer 418 or demand response layer 414 are working properly (e.g., using data aggregated by AM&V layer 412, integrated control layer 418, building subsystem integration layer 420, FDD layer 416, or otherwise). The calculations made by AM&V layer 412 may be based on building system energy models and/or equipment models for individual BMS devices or subsystems. For example, AM&V layer 412 may compare a model-predicted output with an actual output from building subsystems 428 to determine an accuracy of the model.

Fault detection and diagnostics (FDD) layer 416 may be configured to provide on-going fault detection for building subsystems 428, building subsystem devices (i.e., building equipment), and control algorithms used by demand response layer 414 and integrated control layer 418. FDD layer 416 may receive data inputs from integrated control layer 418, directly from one or more building subsystems or devices, or from another data source. FDD layer 416 may automatically diagnose and respond to detected faults. The responses to detected or diagnosed faults may include providing an alert message to a user, a maintenance scheduling system, or a control algorithm configured to attempt to repair the fault or to work-around the fault.

FDD layer 416 may be configured to output a specific identification of the faulty component or cause of the fault (e.g., loose damper linkage) using detailed subsystem inputs available at building subsystem integration layer 420. In other exemplary embodiments, FDD layer 416 is configured to provide “fault” events to integrated control layer 418 which executes control strategies and policies in response to the received fault events. According to some embodiments, FDD layer 416 (or a policy executed by an integrated control engine or business rules engine) may shut-down systems or direct control activities around faulty devices or systems to reduce energy waste, extend equipment life, or assure proper control response.

FDD layer 416 may be configured to store or access a variety of different system data stores (or data points for live data). FDD layer 416 may use some content of the data stores to identify faults at the equipment level (e.g., specific chiller, specific AHU, specific terminal unit, etc.) and other content to identify faults at component or subsystem levels. For example, building subsystems 428 may generate temporal (i.e., time-series) data indicating the performance of BMS 400 and the various components thereof. The data generated by building subsystems 428 may include measured or calculated values that exhibit statistical characteristics and provide information about how the corresponding system or process (e.g., a temperature control process, a flow control process, etc.) is performing in terms of error from its set point. These processes may be examined by FDD layer 416 to expose when the system begins to degrade in performance and alert a user to repair the fault before it becomes more severe.

HVAC Actuator

Referring now to FIGS. 5, an actuator 502 for use in a HVAC system includes one or more auxiliary switches 560 and 562 according to an exemplary embodiment. In some implementations, actuator 502 with switches 560 and 562 may be used in HVAC system 100, waterside system 200, airside system 300, or BMS 400, as described with reference to FIGS. 1-4. For example, actuator 500 is a damper actuator, a valve actuator, a fan actuator, a pump actuator, fire safety actuator, or any other type of actuator that can be used in a HVAC system or BMS. In various embodiments, actuator 502 is a linear actuator (e.g., a linear proportional actuator), a non-linear actuator, a rotational actuator, a capacitive return actuator, or a non-spring return actuator.

Auxiliary switches 560 and 562 can be provided within housing of actuator 502 and can be coupled to processing components of actuator 502. In some embodiments actuator 502 contains a brushless direct current (BLDC) motor and a processing circuit 536 configured to provide a pulse width modulated (PWM) DC output to control the speed of the BLDC motor. The processing circuit 536 may be configured to compare a representation of the electric current output to the BLDC motor to a threshold and may hold the PWM DC output in an off state when the current exceeds the threshold. In some embodiments, the processing circuit is configured to set the PWM DC output to zero and then ramp up the PWM DC output when actuator 502 approaches an end stop. In some embodiments, the processing circuit 536 is coupled to one or more inductive sensors or other positional sensors (e.g., optical sensors, limit switches, etc.) configured to measure the position of actuator 500. In some embodiments, processing circuits 536 determines position without the use of sensors by calculating position in response to electronic feedback or by counting control commands to determine position.

Referring now to FIGS. 5, actuator 502 is embodied as capacitive return actuator and various systems and processes for storing energy for return operations and auxiliary switching operations when power is removed. In brief overview, FIG. 5 shows a block diagram of an actuator that includes a super capacitor or other storage devices with adjustable charge voltage or storing sufficient energy for the return operation and the auxiliary switching operations.

Referring particularly to FIG. 5, a block diagram of an actuator that includes a super capacitor with adjustable charge voltage, according to some embodiments. Actuator 502 can include one or more other capacitors for energy storage in some embodiments. Actuator 502 may be used to service a building (e.g., building 10). For example, actuator 502 may be part of waterside system 200. Actuator 502 may be or may be part of a failsafe device (e.g., a device configured to fail in a specific position when power is removed). In some embodiments, actuator 502 is integrated within a building management system (e.g., BMS 400). For example, actuator 502 may send service request indications to BMS 400. Actuator 502 may facilitate the reduction of aging effects in super capacitors. By reducing the effects of aging for capacitors, actuator 502 may increase nominal capacity and reduce the equivalent series resistance (“ESR”) of super capacitors. Therefore, the super capacitors may have an extended life cycle and charge to higher voltages later in their life cycle.

Actuator 502 offers a number of benefits over existing actuators. Actuator 502 may be a failsafe device that includes a capacitor to facilitate driving actuator 502 to a failsafe position in the event of a failure event (e.g., loss of power, etc.). Traditional failsafe devices typically include a spring to facilitate return to a failsafe position. A spring limits the failsafe position to an extreme (e.g., actuator fully extended, actuator fully retracted). Furthermore, a failsafe device including a spring to facilitate return to a failsafe position requires the failsafe device to continuously fight against the action of the spring and does not have power to control non-mechanically actuated auxiliary switches. For example, the failsafe device must continuously overcome the action of the spring during normal operation, thereby requiring extra energy to power the failsafe device and making the failsafe device inefficient. Actuator 502 may facilitate return to a failsafe position that is not an extreme (e.g., in-between fully extended and fully retracted). For example, in a three-valve scenario actuator 502 may return to a failsafe position that is in the middle of the three-valve. In various embodiments, actuator 502 does not include a spring to facilitate return to a failsafe position and therefore does not have to fight against the action of the spring, thereby increasing an efficiency of actuator 502 over traditional failsafe devices.

Actuator 502 is shown to include capacitor 504, power supply 506, voltage regulator 514, motor 516, drive device 518, position sensors 520, communications circuit 526, and processing circuit 536. In this exemplary embodiment, FIG. 5 is of actuator 502 for building subsystem 428. However, in other embodiments the implementation of a super capacitor with adjustable charge voltage is used for a different device. In some embodiments, the device may be a device outside of building subsystems 428 or within a different subsystem of building subsystem 428. For example, instead of being an actuator, the device may be a chiller, a boiler, a rooftop air handling unit (AHU), or other client devices.

Actuator 502 includes a processing circuit 536 communicably coupled to motor 516. In some embodiments, motor 516 is a brushless DC (“BLDC”) motor. Processing circuit 536 is shown to include a main actuator controller 524, memory 532, and a processor 534. Processor 534 may be a general purpose or specific purpose processor, an application specific integrated circuit (“ASIC”), one or more field programmable gate arrays (“FPGA”), a group of processing components, or other suitable processing components. Processor 534 may be configured to execute computer code or instructions stored in memory 532 or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.).

Memory 532 may include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory 532 may include random access memory (“RAM”), read-only memory (“ROM”), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and/or computer instructions. Memory 532 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Memory 532 may be communicably connected to processor 534 via processing circuit 536 and may include computer code for executing (e.g., by processor 534) one or more processes described herein. When processor 534 executes instructions stored in memory 532, processor 534 generally configures actuator 502 (and more particularly processing circuit 536) to complete such activities.

Main actuator controller 524 (e.g., a main control unit) may be configured to receive external control data 530 (e.g., position setpoints, speed setpoints, etc.) from communications circuit 526 and position signals 522 from position sensors 520 and/or internally calculate position data. Main actuator controller 524 may be configured to determine the position of motor 516 and/or drive device 518 based on position signals 522. In some embodiments, main actuator controller 524 receives data from additional sources. For example, main actuator controller 524 may receive information from sensors (e.g., temperature sensors, humidity sensors, etc.) within building subsystems 428, as described in detail with reference to FIG. 4. Main actuator controller 524 is configured to control actuator switches 560 and 562 in response to position measurements in some embodiments.

Motor 516 may be coupled to drive device 518. Drive device 518 may be a drive mechanism, a hub, or other device configured to drive or effectuate movement of a HVAC system component (e.g., equipment 538). For example, drive device may be configured to receive a shaft of a damper, a valve, or any other movable HVAC system component in order to drive (e.g., rotate) the shaft. In some embodiments, actuator 502 includes a coupling device configured to aid in coupling drive device 518 to the movable HVAC system component. For example, the coupling device may facilitate attaching drive device 518 to a valve or damper shaft.

Position sensors 520 may include Hall effect sensors, potentiometers, optical sensors, or other types of sensors configured to measure the rotational position of the motor 516 and/or drive device 518. Position sensors 520 may provide position signals 522 to processing circuit 536. Main actuator controller 524 may use position signals 522 to determine whether to operate the motor 516. For example, main actuator controller 524 may compare the current position of drive device 518 with a position setpoint received via an external data input (e.g., for external control data 530) and may operate the motor 516 to achieve the position setpoint.

Actuator 502 is further shown to include a communications circuit 526. Communications circuit 526 may be a wired or wireless communications link and may use any of a variety of disparate communications protocols (e.g., BACnet, LON, WiFi, Bluetooth, NFC, TCP/IP, etc.). In some embodiments, communications circuit 526 is an integrated circuit, chip, or microcontroller unit (“MCU”) configured to bridge communications actuator 502 and external systems or devices. In some embodiments, communications circuit 526 is the Johnson Controls BACnet on a Chip (“JBOC”) product. For example, communications circuit 526 may be a pre-certified BACnet communication module capable of communicating on a building automation and controls network (BACnet) using a master/slave token passing (“MSTP”) protocol. Communications circuit 526 may be added to any existing product to enable BACnet communication with minimal software and hardware design effort. In some embodiments, communications circuit 526 provides a BACnet interface for actuator 502. Further details regarding the JBOC product are disclosed in U.S. patent application Ser. No. 15/207,431 filed Jul. 11, 2016, the entire disclosure of which is incorporated by reference herein.

Communications circuit 526 may also be configured to support data communications within actuator 502. In some embodiments, communications circuit 526 may receive internal actuator data 528 from main actuator controller 524. For example, internal actuator data 528 may include a measured or calculated motor torque, the actuator position or speed, configuration parameters, end stop locations, stroke length parameters, commissioning data, equipment model data, firmware versions, software versions, time series data, a cumulative number of stop/start commands, a total distance traveled, an amount of time required to open/close equipment 538 (e.g., a valve), or any other type of data used or stored internally within actuator 502. In some embodiments, communications circuit 526 may transmit external data 530 to main actuator controller 524. External data 530 may include, for example, position setpoints, speed setpoints, control signals, configuration parameters, end stop locations, stroke length parameters, commissioning data, equipment model data, actuator firmware, actuator software, or any other type of data which may be used by actuator 502 to operate the motor 516 and/or drive device 518.

In some embodiments, external data 530 is a DC voltage control signal. Actuator 502 may be a linear proportional actuator configured to control the position of drive device 518 according to the value of the DC voltage received. For example, a minimum input voltage (e.g., 0.0 VDC) may correspond to a minimum rotational position of drive device 518 (e.g., 0 degrees, −5 degrees, etc.), whereas a maximum input voltage (e.g., 10.0 VDC) may correspond to a maximum rotational position of drive device 518 (e.g., 90 degrees, 95 degrees, etc.). Input voltages between the minimum and maximum input voltages may cause actuator 502 to move drive device 518 into an intermediate position between the minimum rotational position and the maximum rotational position. In other embodiments, actuator 502 may be a non-linear actuator or may use different input voltage ranges or a different type of input control signal (e.g., AC voltage or current) to control the position and/or rotational speed of drive device 518.

In some embodiments, external data 530 is an AC voltage control signal. Communications circuit 526 may be configured to transmit an AC voltage signal having a standard power line voltage (e.g., 120 VAC or 230 VAC at 50/60 Hz). The frequency of the voltage signal may be modulated (e.g., by main actuator controller 524) to adjust the rotational position and/or speed of drive device 518. In some embodiments, actuator 502 uses the voltage signal to power various components of actuator 502. Actuator 502 may use the AC voltage signal received via communications circuit 526 as a control signal, a source of electric power, or both. In some embodiments, the voltage signal is received from a power supply line that provides actuator 502 with an AC voltage having a constant or substantially constant frequency (e.g., 120 VAC or 230 VAC at 50 Hz or 60 Hz). Communications circuit 526 may include one or more data connections (separate from the power supply line) through which actuator 502 receives control signals from a controller or another actuator (e.g., 0-10 VDC control signals).

In some embodiments, actuator 502 is an actuator in building subsystems 428. Alternatively, actuator 502 may be outside of building subsystems 428 (not shown). Actuator 502 may be configured to be connected to capacitor 504 and powered by capacitor 504. Actuator 502 may consume electricity from an electric utility and may also be powered by power supply 506. The initial position (P_i) of actuator 502 and the final position (P_f) of actuator 502 may be input to memory 532. The initial position (P_i) of actuator 502 may be the position of actuator 502 when processor 534 first receives a signal that power is lost to actuator 502 from power supply 506 (e.g., a first indication of no power). The final position (P_f) of actuator 502 may be the position of actuator 502 (e.g., an actuator) when actuator 502 returns to a default position.

Still referring to FIG. 5, memory 534 may be configured to store various modules that may calculate the charge voltage (V_c) (i.e., a maximum voltage level that may be used to charge the super capacitor). In this exemplary embodiment, memory 534 is shown to include main actuator controller 524, capacitance module 508, energy module 510, and charge voltage module 512. However, in some embodiments, memory 534 includes more modules and/or excludes one or more of the modules shown in FIG. 5. For example, memory 534 may include one module that completes both calculations performed by energy module 510 and capacitance module 508.

In some embodiments, capacitance module 508 is configured to determine a capacitance (C) of a super capacitor (e.g., capacitor 504). In some embodiments, capacitance module 508 receives inputs from memory 534. The inputs may correspond to the voltage measured across the super capacitor at time t₁ and the voltage measured across the super capacitor at time t₂; voltages V₁ and V₂ respectively. Using these voltage readings, capacitance module 508 may determine the capacitance of the super capacitor using Equation 1:

C = ( V 1 - V 2 ) ( t 1 - t 2 ) ( 1 )

In some embodiments, the difference between t₁ and t₂ is a predetermined length of time. Advantageously, this may ensure that the time between each voltage measurement is consistent for calculating the capacitance for each power cycle of the power supply. In some embodiments, capacitance module 508 outputs the determined capacitance (C) to energy module 510 and charge voltage module 512 to be used in other calculations.

In some embodiments, energy module 510 is configured to determine the energy value (W_r) used for a device (e.g., actuator 502) to return to a default position after losing power. Additionally, the calculation of W_r may be stored in non-volatile memory (e.g., memory 532). After W_r is determined by energy module 510, the value of W_r may be output to charge voltage module 512. In some embodiments, energy module 510 calculates W_r by taking the difference between two values of energy, initial energy W_i and final energy W_f. W_i, W_f, and W_r is determined using Equation 2, Equation 3, and Equation 4, respectively:

W i = 1 2 ⁢ CV i 2 ( 2 ) W f = 1 2 ⁢ CV f 2 ( 3 ) W r = W i - W f ( 4 )

where C is the calculated capacitance from capacitance module 508, V_i is the voltage across the super capacitor when actuator 502 is at an initial position P_i, and V_f is the voltage across the super capacitor when actuator 502 is at a final position Pf.

In some embodiments, charge voltage module 512 is configured to determine the charge voltage (V_c) (i.e., a maximum voltage level that may be used to charge the super capacitor). For example, charge voltage module 512 calculates V and outputs voltage data to voltage regulator 514 in order to regulate capacitor 504. In some embodiments, charge voltage module 512 receives inputs from capacitance module 508 and energy module 510 within memory 532 that include values for capacitance (C) and energy value (W_r), respectively. Using the previously determined values of C and W_r, charge voltage module 512 may calculate the value of charge voltage using Equation 5:

V c = 2 ⁢ W r c ( 5 )

where W_r is the energy used to return the device to a default position after power is lost C is the capacitance of the super capacitor. After completion of calculating charge voltage, charge voltage module 512 may be configured to output the determined value of charge voltage as voltage data to voltage regulator 514.

Voltage regulator 514 may be configured to control charge voltage (V_c). In some embodiments the voltage regulator may take the form of a potentiometer configured to control V_c by changing the feedback resistance of a power supply for each power cycle of the power supply. However, in other embodiments the voltage regulator may take the form of a digital to analog converter configured to control Ve by changing the feedback resistance attached to a regulator feedback pin for each power cycle of the power supply. In yet other embodiments the voltage regulator may take the form of a silicon controlled rectifier configured to control Ve by changing a feedback resistance of a power supply for each power cycle of the power supply. In still other embodiments the voltage regulator may take the form of an adjustable power supply output configured to control Ve by a variable output adjusted for each power cycle of the power supply. When actuator 502 is first powered on, processor 534 may initialize Ve to a rated voltage for capacitor 504. In some embodiments, the calculated Ve is input as voltage data to voltage regulator 514 from charge voltage module 512 for every cycle of the power supply.

In some embodiments, energy module 510 is configured to cause capacitor 504 or other devices to store sufficient energy required to return the failsafe device to the failsafe position and to run processing circuit 536 so that it can control switches 560 and 562 until the return operation is completed or for a sufficient amount of time. The term W_r is the energy used to return the device to a default position after power is lost plus the amount of energy for controlling auxiliary switches 560 and 562 while the device is returned to the default position in some embodiments. The term W_R can include the amount of energy required to actuate switches 560 and 562 and the amount of energy required to operate the MCU or processing circuit 536. In some embodiments, a separate capacitor from capacitor 504 is provided to store the amount of energy required to actuate switches 560 and 562 and the amount of energy required to operate processing circuit 536.

With reference to FIG. 6, an actuator 600 is a non-spring return actuator (e.g., a capacitive return actuator or a non-return actuator) in some embodiments. Actuator 600 can be embodied as a capacitive return actuator similar to actuator 502 or can be a non-return actuator (e.g., an actuator employed in an application where return to a default position is not required in the event of a power failure). Actuator 600 is coupled to HVAC equipment 606 (e.g., a damper, valve, etc.) and includes or is coupled to an auxiliary switch 610.

Auxiliary switch 610 is a coupled to a device 608 (e.g., a fan, etc.) and can be used to control power to device 608 based upon a command from actuator 600. The command can be based upon a position of actuator 600 (e.g., position of drive device 626) or other criteria. Switch 610 can also be used to provide feedback (e.g., position feedback) to other devices or a remote system 612 (e.g., remote server) in communication with actuator 600. Set points for controlling switch 610 can be provided to actuator 600 via a communications circuit (e.g., similar to circuit 526 FIG. 5). The setpoints can be provided by the remote system 612 or form a user (e.g., via NFC) in some embodiments.

Auxiliary switch 610 can be one or more switches such as relay switches. In some embodiments, switch 610 is a latch relay switch or pulse relay switch including a contact 618. Contact 618 can be one or more sets of normally closed and/or normally open contacts. Switch 610 can include an electromagnetic coil for actuating the contact 618 and a mechanical and/or magnetic mechanism to latch the contact 618 into a state. In some embodiments, the switch 610 includes a bistable mechanism for holding the contact 618 in one of two stable two stable states (e.g., “on” (closed) or “off” (open) position until triggered to switch states again). The control signal to acuate switch 610 can be a triggering pulse signal in some embodiments.

Actuator 600 includes a control unit 620 (e.g., an MCU) a power supply 624, a sensor 630, and a drive system or device 626. Actuator 600 can also include an uninterruptable power supply 628 (e.g., for return applications), and a user interface 622 for receiving commands (e.g., setpoints) from a user. Power supply 628 can include one or more capacitors 629 (e.g., capacitor 504 (FIG. 5)) configured to store energy for controlling switch 610 and drive device 626 in the event power supply 624 cannot provide power.

Sensor 520 is a position sensor configured to provide a position signal indicative of position of drive device 626 or HVAC equipment 606. Sensor 520 can be an inductive sensor, a mechanical sensor, or an optical sensor in some embodiments.

Control unit 620 responds to the position signal to control drive device 626 and/or switch 610 in some embodiments. For example, device 608 can be powered using switch 610 when control unit 620 has driven equipment 606 to a position (e.g., 40% open). In some embodiments, control unit 620 calculates position of drive device 626 based upon other criteria (e.g., motor signals) and does not use sensor 520 for position determinations.

User interface 622 can include a display and buttons, touch screen, or other medium for entering data. A user can provide set points for actuating switch 610 using NFC, user interface 622, or remote system 612. The set points can be for actuating switches in response to position or selecting an amount of energy to be stored by power supply 628. In some embodiments, control unit 620 can actuate switch 610 in response to a power failure. Drive device 626 can include one or more gears and other mechanical components for equipment 606. Drive device 626 can be similar to drive device 578 (FIG. 5) in some embodiments.

In come embodiments, control unit 620 can be configured to open and close one or more switches such as switch 610 at different setpoints. In some embodiments, the auxiliary switches can open or close when a first position is reached in a first direction of travel and when a second position is reached at on opposite direction of travel. In some embodiments, by using setpoints that are specific to a direction of travel, hysteresis based upon direction of travel can be provided by choosing setpoints appropriately. In some embodiments, different switch setpoints can be provided when a position of device 626 is increasing or decreasing. For example, control unit 620 can set switch 510 to activate at a 10° position when device 626 is driven from a 0° position (or increasing position) and deactivate at an 8° position when driven from the 90° position (or decreasing position).

In some embodiments, control unit 620 can be configured to control switches based upon additional criteria than position setpoints and/or in addition to position setpoints. In some embodiments, additional logic for controlling switch one or more switches such as switch 610 can be provided by control unit 620. For example, control unit 620 can be configured to change a setpoint over time to turn a fan on/off when the damper position was more optimal. In another example, control unit 620 is configured to change a setpoint based upon a motor condition such as a stall condition. In some embodiments, the switch 610 is activated when actuator 600 reaches the fully damper closed/open position when the control unit 620 detects an end of travel stall condition. Stall conditions can be sensed by motor current sensing techniques or other techniques.

Configuration of Exemplary Embodiments

The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.

The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media may be any available media that may be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media may comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which may be used to carry or store desired program code in the form of machine-executable instructions or data structures and which may be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Although the figures show a specific order of method steps, the order of the steps may differ from what is depicted. Also, two or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish the various connection steps, processing steps, comparison steps and decision steps.