VARIABLE REFRIGERANT FLOW SYSTEM WITH MULTI-LEVEL MODEL PREDICTIVE CONTROL

    公开(公告)号:US20180004173A1

    公开(公告)日:2018-01-04

    申请号:US15635754

    申请日:2017-06-28

    Abstract: A model predictive control system is used to optimize energy cost in a variable refrigerant flow (VRF) system. The VRF system includes an outdoor subsystem and a plurality of indoor subsystems. The model predictive control system includes a high-level model predictive controller (MPC) and a plurality of low-level indoor MPCs. The high-level MPC performs a high-level optimization to generate an optimal indoor subsystem load profile for each of the plurality of indoor subsystems. The optimal indoor subsystem load profiles optimize energy cost. Each of the low-level indoor MPCs performs a low-level optimization to generate optimal indoor setpoints for one or more indoor VRF units of the corresponding indoor subsystem. The indoor setpoints can include temperature setpoints and/or refrigerant flow setpoints for the indoor VRF units.

    VALVE ASSEMBLY WITH LOW FLOW COMPENSATION FOR PROPORTIONAL VARIABLE DEADBAND CONTROL

    公开(公告)号:US20210018214A1

    公开(公告)日:2021-01-21

    申请号:US16516070

    申请日:2019-07-18

    Abstract: A system for controlling a flow rate of a fluid through a valve is provided. The system includes a valve and an actuator. The actuator includes a motor and a drive device that is coupled to the valve for driving the valve between multiple positions. The system further includes a flow rate sensor and a controller that is communicably coupled with the flow rate sensor and the motor. The controller is configured to receive a first flow rate setpoint, determine a first actuator position setpoint using a proportional variable deadband control technique based on the first flow rate setpoint and a flow rate measurement, and receive a second flow rate setpoint. In response to a determination that certain low flow criteria are satisfied, the controller is configured to determine a second actuator position setpoint using the proportional variable deadband control technique based on a low flow compensation setpoint.

    Building HVAC system with multi-level model predictive control

    公开(公告)号:US10809676B2

    公开(公告)日:2020-10-20

    申请号:US16601391

    申请日:2019-10-14

    Abstract: A heating, ventilation, or air conditioning (HVAC) system for a building includes indoor subsystems, a high-level controller, and low-level controllers. Each indoor subsystem includes one or more indoor units configured to provide heating or cooling to one or more building spaces. The high-level controller generates a plurality of indoor subsystem energy targets, each indoor subsystem energy target corresponding to one of the plurality of indoor subsystems and generated based on a thermal capacitance of one or more building spaces to which heating or cooling is provided by the corresponding indoor subsystem. Each low-level indoor controller corresponds to one of the indoor subsystems and generates indoor setpoints for the one or more indoor units of the corresponding indoor subsystem using the indoor subsystem energy target for the corresponding indoor subsystem and operates the one or more indoor units of the corresponding indoor subsystem using the indoor setpoints.

    Valve assembly with low flow compensation for proportional variable deadband control

    公开(公告)号:US11415335B2

    公开(公告)日:2022-08-16

    申请号:US16516070

    申请日:2019-07-18

    Abstract: A system for controlling a flow rate of a fluid through a valve is provided. The system includes a valve and an actuator. The actuator includes a motor and a drive device that is coupled to the valve for driving the valve between multiple positions. The system further includes a flow rate sensor and a controller that is communicably coupled with the flow rate sensor and the motor. The controller is configured to receive a first flow rate setpoint, determine a first actuator position setpoint using a proportional variable deadband control technique based on the first flow rate setpoint and a flow rate measurement, and receive a second flow rate setpoint. In response to a determination that certain low flow criteria are satisfied, the controller is configured to determine a second actuator position setpoint using the proportional variable deadband control technique based on a low flow compensation setpoint.

    Valve assembly with delay compensation for proportional variable deadband control

    公开(公告)号:US11068000B2

    公开(公告)日:2021-07-20

    申请号:US16509264

    申请日:2019-07-11

    Abstract: A system for controlling a flow rate of a fluid through a valve is provided. The system includes a valve and an actuator. An actuator drive device is driven by an actuator motor and is coupled to the valve for driving the valve between multiple positions. The system further includes a flow rate sensor configured to measure the flow rate of the fluid through the valve and a controller that is communicably coupled with the flow rate sensor. The controller is configured to receive a flow rate measurement from the flow rate sensor, adjust a control deadband based on an actuator command history, and determine a compensated position setpoint using the flow rate measurement, the adjusted control deadband, and a proportional variable deadband control technique. The controller is further configured to operate the motor to drive the drive device to the compensated actuator position setpoint.

    BUILDING HVAC SYSTEM WITH MULTI-LEVEL MODEL PREDICTIVE CONTROL

    公开(公告)号:US20200041966A1

    公开(公告)日:2020-02-06

    申请号:US16601391

    申请日:2019-10-14

    Abstract: A heating, ventilation, or air conditioning (HVAC) system for a building includes a plurality of indoor subsystems, a high-level controller, and a plurality of low-level controllers. Each indoor subsystem includes one or more indoor units configured to provide heating or cooling to one or more building spaces. The high-level controller is configured to generate a plurality of indoor subsystem energy targets, each indoor subsystem energy target corresponding to one of the plurality of indoor subsystems and generated based on a thermal capacitance of one or more building spaces to which heating or cooling is provided by the corresponding indoor subsystem. Each low-level indoor controller corresponds to one of the indoor subsystems and is configured to generate indoor setpoints for the one or more indoor units of the corresponding indoor subsystem using the indoor subsystem energy target for the corresponding indoor subsystem and operate the one or more indoor units of the corresponding indoor subsystem using the indoor setpoints.

    VALVE ASSEMBLY WITH DELAY COMPENSATION FOR PROPORTIONAL VARIABLE DEADBAND CONTROL

    公开(公告)号:US20210011497A1

    公开(公告)日:2021-01-14

    申请号:US16509264

    申请日:2019-07-11

    Abstract: A system for controlling a flow rate of a fluid through a valve is provided. The system includes a valve and an actuator. An actuator drive device is driven by an actuator motor and is coupled to the valve for driving the valve between multiple positions. The system further includes a flow rate sensor configured to measure the flow rate of the fluid through the valve and a controller that is communicably coupled with the flow rate sensor. The controller is configured to receive a flow rate measurement from the flow rate sensor, adjust a control deadband based on an actuator command history, and determine a compensated position setpoint using the flow rate measurement, the adjusted control deadband, and a proportional variable deadband control technique. The controller is further configured to operate the motor to drive the drive device to the compensated actuator position setpoint.

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