An operation controlling apparatus of a reciprocating compressor includes: a detector configured to detect a torque output by a motor of the reciprocating compressor, a rotation speed of the motor, a counter electromotive voltage of the motor, and a current applied to the motor; a controller configured to determine a mode switching time point for switching an operation mode of the reciprocating compressor based on the torque, the rotation speed, the counter electromotive voltage, and the current of the motor, and output a control signal for changing a wire ratio of the motor corresponding to the operation mode; and a driver configured to change the wire ratio of the motor based on the control signal and operate the reciprocating compressor in the operation mode among at least two operation modes.

The invention provides an air conditioner control method and device and an air conditioner. The air conditioner control device acquires a current temperature of a chilled water of a unit at a preset period; determine a target load of the unit, a target temperature of a chilled water and a target temperature of a cooling water based on a temperature of the chilled water set by a user and the current temperature of the chilled water; determine an evaporating parameter and a condensing parameter of the unit based on the target load of the unit, the target temperature of the chilled water and the target temperature of the cooling water; and determine operation parameters of a compressor based on the target load of the unit, the evaporation parameter and the condensation parameter. Therefore, the unit can operate based on the operation parameters.

A system includes an electronic power converter and a controller. The electronic power converter supplies power to one or more motor drives of an HVAC and/or refrigeration system. The controller obtains a plurality of pulse width modulation (PWM) algorithms. Each PWM algorithm has an associated harmonic signature. The controller further determines one or more resonance frequencies associated with the HVAC and/or refrigeration system. The controller also selects a first PWM algorithm from the plurality of PWM algorithms based at least in part on the harmonic signature associated with the first PWM algorithm mitigating the one or more resonance frequencies associated with the refrigeration system. The controller further operates the electronic power converter according to the first PWM algorithm.

An air conditioner and a control method thereof are provided. The air conditioner includes: a compressor including a coil; an oil pool connected to the compressor through an oil piping; a main control board configured to receive a power-on signal of the air conditioner, obtain an actual temperature of the oil pool after receiving the power-on signal, generate a required heating amount in response to the actual temperature of the oil pool being lower than a preset startup temperature, and generate timing control signals according to the required heating amount; a power device, wherein two sides of the power device are respectively connected to the main control board and the coil, and the power device is configured to drive the coil to heat the oil pool according to the timing control signals generated by the main control board.

A portable refrigerator includes a main housing, a refrigerator cover, a cooling mechanism, a rechargeable battery pack and a control unit. The cooling mechanism includes heat exchanging tubes, a compressor, an evaporator and a condenser connected to the evaporator and the compressor. The rechargeable battery pack is detachably attached on a power compartment of the main housing. The control unit is supported in the main housing and electrically connected to the rechargeable battery pack and the cooling mechanism for centrally controlling an operation of the cooling mechanism. A to predetermined amount of refrigerant is arranged to controllably pass through the heat exchanging tubes, the condenser, the evaporator and the compressor for extracting heat from the accommodating cavity.

A domestic refrigeration appliance has a heat-insulated housing with a coolable inner container delimiting a coolable interior for storing foods. The interior is cooled with a coolant circuit that includes a compressor with a three-phase motor operated by an actuator via electrically powered motor windings. The actuator is actuated at least indirectly to operate the compressor in a switched-on state with a rotational speed of the three-phase motor at least approximately equal to a predetermined rotational speed. The actuator is caused to switch off the compressor such that the rotational speed of the three-phase motor decreases to a predetermined minimum rotational speed, and thereafter to switch off the three-phase motor for at least a predetermined period of time by de-energizing the motor windings. The period of time is selected long enough to reduce the speed of the motor, beginning from the minimum rotational speed, to reach standstill.

A PFC circuit is provided. A first bridge rectifier receives an AC voltage. A power converter includes a switch and receives an output of the first bridge rectifier, converts the output to a first DC voltage, and supplies the first DC voltage to a DC bus to power a compressor. A second bridge rectifier receives the AC voltage and bypasses at least one of the first bridge rectifier, a choke and a diode of the PFC circuit to provide a rectified AC voltage out of the second bridge rectifier to the DC bus to power the compressor. A control module controls operation of a driver to transition the switch between open and closed states to adjust a second DC voltage on the DC bus, where the second DC voltage, depending on the AC and second DC voltages, is based on the first DC voltage or the rectified AC voltage.

A vehicle, a refrigerator for a vehicle, and a method for controlling a refrigerator for a vehicle are provided. The method for controlling the refrigerator for the vehicle includes turning on a switch of the refrigerator for the vehicle, measuring a temperature of an interior of the refrigerator for the vehicle a first time, measuring a temperature of the interior of the refrigerator for the vehicle again a second time after a predetermined time has elapsed from the first time, determining a temperature change of the interior of the refrigerator from the first time to the second time, and operating the refrigerator for the vehicle in a quench mode in which the temperature in the interior of the refrigerator is rapidly lowered, unlike a normal mode, if the temperature change in the interior of the refrigerator is in a positive direction.

A system includes an electronic power converter and a controller. The electronic power converter supplies power to one or more motor drives of an HVAC and/or refrigeration system. The controller obtains a plurality of pulse width modulation (PWM) algorithms. Each PWM algorithm has an associated harmonic signature. The controller further determines one or more resonance frequencies associated with the HVAC and/or refrigeration system. The controller also selects a first PWM algorithm from the plurality of PWM algorithms based at least in part on the harmonic signature associated with the first PWM algorithm mitigating the one or more resonance frequencies associated with the refrigeration system. The controller further operates the electronic power converter according to the first PWM algorithm.

Described is a vector control system for a vapor compression circuit. The vector control system may monitor the vapor compression circuit and adjust the speed of one or more motors to increase efficiency by taking into account the torque forces placed on a compressor motor.