Method for controlling a compressor of a thermal storage heat pump system

Abstract

A method of controlling a compressor of a thermal storage heat pump system of a vehicle is provided. The system may operate in one of a heating mode and a cooling mode, as determined by at least one system controller based on at least one parameter. The at least one parameter may be ambient air temperature. The compressor has a compressor motor and a motor controller configured to selectively operate the compressor in an unmodified state or a modified state based on the operating mode of the system. The compressor motor is operated in the unmodified state when the system is in the cooling mode, and in the modified state when the system is in the heating mode. Operating the compressor motor in the modified state may include decreasing its coefficient of performance (COP).

1 . A method for controlling a compressor of a thermal storage heat pump system in a vehicle having a passenger compartment, the thermal storage heat pump system including a refrigeration circuit in thermal communication with a first coolant circuit and a second coolant circuit, the compressor being located in the refrigeration circuit and having a compressor motor and a motor controller, the method comprising:
 receiving, by at least one system controller, a measurement of at least one parameter;   determining, by the at least one system controller, an operating mode of the thermal storage heat pump system based on the measurement of the at least one parameter; and   operating, by the motor controller, the compressor motor in one of an unmodified state and a modified state based on the operating mode of the thermal storage heat pump system;   wherein the operating mode is one of a heating mode and a cooling mode; and   wherein the compressor motor is operated in the unmodified state when the thermal storage heat pump system is in the cooling mode, and in the modified state when the thermal storage heat pump system is in the heating mode.   
     
     
         2 . The method of  claim 1  wherein the at least one parameter is ambient air temperature. 
     
     
         3 . The method of  claim 2  wherein the measurement of the ambient air temperature is taken and transmitted to the at least one system controller by a temperature sensor. 
     
     
         4 . The method of  claim 2  wherein the operating mode is the heating mode when the measurement of the ambient air temperature is at or below a switchover temperature, and is the cooling mode when the measurement of the ambient air temperature is above the switchover temperature. 
     
     
         5 . The method of  claim 1  wherein the compressor motor is a brushless direct current (DC) electric motor that has a coefficient of performance (COP), and is a three-phase system in which each phase is offset by a set angle and has a defined frequency in the unmodified state. 
     
     
         6 . The method of  claim 5  wherein the operating of the compressor motor in a modified state comprises reducing the COP of the compressor motor. 
     
     
         7 . The method of  claim 6  wherein the reducing of the COP comprises offsetting from the set angle at least one of the phases of the compressor motor. 
     
     
         8 . The method of  claim 6  wherein the reducing of the COP comprises altering the defined frequency of at least one of the phases of the compressor motor. 
     
     
         9 . A thermal storage heat pump system of a vehicle having a passenger compartment, the system comprising:
 a first coolant circuit configured to circulate a first coolant;   a second coolant circuit configured to circulate a second coolant;   a refrigeration circuit configured to circulate a refrigerant, the refrigeration circuit being in thermal communication with the first coolant circuit and the second coolant circuit via a first heat exchanger and a second heat exchanger, respectively;   a compressor located in the refrigeration circuit, the compressor being configured to compress the refrigerant, and having a compressor motor and a motor controller configured to selectively operate the compressor motor in one of an unmodified state and a modified state; and   at least one system controller configured to selectively operate the thermal storage heat pump system in one of a heating mode and a cooling mode based on a measurement of at least one parameter;   wherein the compressor motor is operated in the unmodified state when the thermal storage heat pump system is in the cooling mode, and in the modified state when the thermal storage heat pump system is in the heating mode.   
     
     
         10 . The thermal storage heat pump system of  claim 9  wherein the at least one parameter is ambient air temperature. 
     
     
         11 . The thermal storage heat pump system of  claim 10  further comprising a temperature sensor configured to measure the ambient air temperature to obtain an ambient air temperature measurement, and to transmit the ambient air temperature measurement to the at least one system controller. 
     
     
         12 . The thermal storage heat pump system of  claim 11  wherein the operating mode is the heating mode when the ambient air temperature measurement is at or below a switchover temperature, and is the cooling mode when the ambient air temperature measurement is above the switchover temperature. 
     
     
         13 . The thermal storage heat pump system of  claim 9  wherein the compressor motor is a brushless direct current (DC) electric motor that has a coefficient of performance (COP), and is a three-phase system in which each phase is offset by a set angle and has a defined frequency in the unmodified state. 
     
     
         14 . The thermal storage heat pump system of  claim 13  wherein the COP when the thermal storage heat pump system is in the heating mode is less than the COP when the thermal storage heat pump system is in the cooling mode. 
     
     
         15 . The thermal storage heat pump system of  claim 14  wherein at least one of the phases of the compressor motor is offset from the set angle. 
     
     
         16 . The thermal storage heat pump system of  claim 14  wherein at least one of the phases has an altered frequency different from the defined frequency. 
     
     
         17 . A method for controlling a compressor of a thermal storage heat pump system having at least one system controller and a refrigeration circuit in which the compressor is located, the compressor having a compressor motor and a motor controller, the method comprising:
 measuring, by a temperature sensor, ambient air temperature to obtain a temperature measurement;   transmitting, by the temperature sensor, the temperature measurement to the at least one system controller;   determining, by the at least one system controller, an operating mode of the thermal storage heat pump system based on the temperature measurement, the operating mode being one of a heating mode and a cooling mode; and   operating, by the motor controller, the compressor motor in an unmodified state when the thermal storage heat pump system is in the cooling mode, and in the modified state when the thermal storage heat pump system is in the heating mode.   
     
     
         18 . The method of  claim 17  wherein the operating mode is the heating mode when the temperature measurement is at or below a switchover temperature, and is the cooling mode when the temperature measurement is above the switchover temperature. 
     
     
         19 . The method of  claim 17  wherein the compressor motor is a brushless direct current (DC) electric motor that has a coefficient of performance (COP), and is a three-phase system in which each phase is offset by a set angle and has a defined frequency in the unmodified state. 
     
     
         20 . The method of  claim 19  wherein the operating of the compressor motor in a modified state comprises reducing the COP of the compressor motor by at least one of offsetting from the set angle at least one of the phases of the compressor motor, altering the defined frequency of at least one of the phases of the compressor motor, and adding mechanical losses internal to the compressor motor.