A method for controlling torque of an air conditioner compressor is disclosed. In one example, the air conditioner compressor is a variable displacement compressor. The method may provide smooth transitions between different air conditioner compressor torques.

A method for adaptive power engine control of a transport refrigeration unit (TRU) is provided. The method includes determining a current compressor power of a compressor of the TRU. The method also includes determining an adaptive compressor power error of the compressor. Also, the method includes calculating and setting a target compressor power of the compressor based on the current compressor power and the adaptive compressor power error. Further, the method includes determining a suction pressure control point of the compressor based on the target compressor power and a compressor curve map. Moreover, the method includes operating the compressor with the suction pressure control point of the compressor.

An HVAC system includes a variable-speed compressor which compresses refrigerant flowing through the HVAC system, a blower which provides a flow of air through the HVAC system at a controllable flow rate, and a controller communicatively coupled to the variable-speed compressor and the blower. The controller receives a demand request, which includes a command to operate the HVAC system at a predefined setpoint temperature. In response to receiving the demand request, a setpoint temperature associated with the HVAC system can be adjusted to the predefined setpoint temperature. A speed of the variable-speed compressor is decreased to a low-speed setting. Based on the decreased speed of the variable-speed compressor, an air-flow rate can be determined to provide by the blower. The controllable flow rate of the flow of air provided by the blower can be adjusted based on the determined air-flow rate.

An HVAC system includes a variable-speed compressor which compresses refrigerant flowing through the HVAC system, a blower which provides a flow of air through the HVAC system at a controllable flow rate, and a controller communicatively coupled to the variable-speed compressor and the blower. The controller receives a demand request, which includes a command to operate the HVAC system at a predefined setpoint temperature. In response to receiving the demand request, a setpoint temperature associated with the HVAC system is adjusted to the predefined setpoint temperature. A speed of the variable-speed compressor is decreased to a low-speed setting. Based on the decreased speed of the variable-speed compressor, an air-flow rate is determined to provide by the blower. The controllable flow rate of the flow of air provided by the blower is adjusted based on the determined air-flow rate.

A system for controlling a compressor may include an engine controller controlling a fuel injection amount corresponding to an engine load and an opening amount of a throttle by reflecting a required torque required for an air conditioner, an operation information detector for detecting operation information according to driving state of the vehicle, a compressor generating pressure through a piston operation of a cylinder utilizing the power of the engine during operation of the air conditioner, and a controller determining an engine negative pressure of an intake manifold stored in the brake booster at a value, and when the negative pressure of intake manifold is below a first threshold value when the brake is operated, the engine enters a negative pressure recovery mode for predicting an insignificant negative pressure drop condition that falls below a second threshold value which is the A/C cut control condition and reduces the A/C duty.

An HVAC system includes a variable-speed compressor which compresses refrigerant flowing through the HVAC system, a blower which provides a flow of air through the HVAC system at a controllable flow rate, and a controller communicatively coupled to the variable-speed compressor and the blower. The controller receives a demand request, which includes a command to operate the HVAC system at a predefined setpoint temperature. In response to receiving the demand request, a setpoint temperature associated with the HVAC system is adjusted to the predefined setpoint temperature. A speed of the variable-speed compressor is decreased to a low-speed setting. Based on the decreased speed of the variable-speed compressor, an air-flow rate is determined to provide by the blower. The controllable flow rate of the flow of air provided by the blower is adjusted based on the determined air-flow rate.

Methods and systems are provided for an air conditioning system. An example method of determining current through a compressor suction valve in a vehicle air conditioning (AC) system is provided, the AC system comprises an evaporator fan and the method includes determining the speed of the evaporator fan and determining the current through the suction valve based on the speed of the evaporator fan.

A system for controlling a compressor may include an engine controller that controls a fuel injection amount corresponding to an engine load and an opening amount of a throttle by reflecting a required torque required for an air conditioner (A/C), an operation information detector for detecting operation information according to driving state of the vehicle, a compressor that generates pressure during operation of the A/C, an air conditioner relay which is turned on when the air conditioner operates and is turned off when the A/C is stopped, and a controller which determines an engine negative pressure of an intake manifold, and when the cooling water temperature is lower than the predetermined temperature and the intake manifold pressure is lower than the first threshold value, a cold-start intake manifold negative pressure insufficient event is generated to reduce the A/C duty in accordance with the entry into a negative pressure recovery mode.

During control of an air-conditioning for a vehicle, when a torque to the engine is outputted that satisfies a total value of drive torques of the vehicle and an air-conditioning compressor, a minimum discharge capacity is set when fuel to the engine is cut. An assessment is made as to whether or not the discharge capacity needs to be changed from the minimum discharge capacity in accordance with the state inside the cabin. The discharge capacity is changed from the minimum discharge capacity to an upper limit capacity that is allowed during normal operation upon accessing that the discharge capacity needs to be changed from the minimum discharge capacity. After a predetermined time elapses following the changing of the discharge capacity, the discharge capacity is changed from the upper limit capacity to a discharge capacity that corresponds to the state inside the cabin.

A refrigeration system for a vehicle includes a compressor in fluid communication with a condenser and an evaporator. The compressor includes a variable speed motor and employs capacity modulation using refrigerant injection. The condenser and the evaporator include variable speed fans. The refrigeration system includes a battery to supply power to the refrigeration system. The battery is charged by one or more sources of power including the vehicle. The refrigeration system includes a control module configured to monitor one or more characteristics of the battery and to control one or more operating parameters of one or more of the compressor, the condenser, and the evaporator based on the one or more characteristics of the battery.