A motor control interface system, comprising an interface communication module configured to connect to a wired control port of a rotating electronically controlled motor, such as in an HVAC system, wherein the interface communication module converts a rotating motor speed signal to a wireless signal for receipt by an external monitoring device. The speed output signal comprises a digital square wave signal, and the communication module implements a reciprocal frequency counter method to determine the speed of the motor. The interface communication module wirelessly transmits the motor speed information to a handheld wireless device, such as a smartphone.

A heat pump device capable of efficiently and reliably preventing a liquid refrigerant from stagnating in a compressor an air conditioner, a heat pump water heater, a refrigerator, and a freezing machine including the heat pump device. The configuration is such that, when the compressor is under operation standby, a high-frequency voltage synchronizing with a carrier signal is supplied to the compressor motor to carry out the locked energization of the compressor motor. From respective inter-phase voltages, respective phase voltages, or respective phase currents of the compressor motor for a plurality of high-frequency energization cycles, the detection values for one high-frequency energization cycle are restored. A power value calculated using the restored detection values for one high-frequency energization cycle is controlled to coincide with a heating power command necessary for discharging the liquid refrigerant stagnated in the compressor to the outside of the compressor.

A power conversion apparatus includes: an inverter to drive a motor, using a first carrier signal; an inverter connected in parallel to the inverter, to drive a motor, using a second carrier signal; respective phase lower arm shunt resistors to detect a first current flowing inside the inverter; respective phase lower arm shunt resistors to detect a second current flowing in the inverter; and a control unit to control the inverters. A phase difference is set between the first carrier signal and the second carrier signal to prevent a detection period for the first current in the first carrier signal and a detection period for the second current in the second carrier signal from overlapping each other when the inverters are controlled.

Disclosed are an inverter circuit, and air conditioner and refrigerator using the same. The inverter circuit includes a rectifier configured to rectify an input Alternating-Current (AC) voltage into a Direct-Current (DC) voltage; a smoothing portion configured to smoothen the DC voltage output from the rectifier; an inverter connected to a load, and configured to convert the DC voltage smoothened by the smoothing portion into an AC voltage, and to output the AC voltage to the load; and a suppressor installed between the rectifier and the smoothing portion, and configured to suppress an overvoltage or overcurrent of a DC link to which the DC voltage from the smoothing portion is applied.

A compressor driving apparatus and an air conditioner including the same, whereby the compressor driving apparatus includes a capacitor connected to a DC terminal, an inverter, including a plurality of three-phase switching devices, to convert DC power from the capacitor into AC power to drive a compressor motor, an output current detector to detect output current flowing in the motor, and a controller to output a switching control signal for controlling the inverter based on the output current, wherein the controller performs control such that some of the three-phase switching devices in the inverter are turned on or off in a compressor preheating mode.

A control method and system for a resonant linear compressor applied for controlling the capacity of a cooling system. The method includes: a) reading a reference operation power (P.sub.ref) of the motor of the compressor; b) measuring an operation current (i.sub.MED); c) measuring an operation voltage of a control module of the compressor; d) calculating an input power (P.sub.MED) of the motor as a function of the operation current (i.sub.MED) and of the operation voltage; e) comparing the input power (P.sub.MED) with the reference operation power (P.sub.ref); f) if the reference operation power (P.sub.ref) is higher than the input power (P.sub.MED), then increase an operation voltage of the compressor (UC); g) if the reference operation power (P.sub.ref) is lower than the input power (P.sub.MED), then decrease the operation voltage of the compressor (UC).

A compressor of a refrigeration appliance includes a motor, in particular a BLDC motor, and a controller for stopping the motor. The controller is configured to slow down the motor rotating in a first rotating direction until it comes to a standstill and to subsequently position the rotor relative to the stator, in a second rotating direction with a predetermined torque. A method for stopping a compressor of a refrigeration appliance is also provided.

A method is provided for braking a compressor of a refrigeration appliance, of an air conditioning appliance or of a heat pump in which the compressor has a brushless motor with windings and a controller for braking the motor. The controller is configured to brake the brushless motor by using a braking current in a controlled manner starting from an operating rotational speed, in which the braking current during the controlled braking is dependent on induced voltages determined before the controlled braking. The method for braking includes rotating the motor at an operating rotational speed, receiving a signal for decelerating, braking or slowing down, determining voltages induced in the windings and supplying a braking current having a decreasing frequency to the windings, in which the braking current during the braking is dependent on the previously determined induced voltages. A compressor and a refrigeration appliance having the compressor are also provided.

A two-stage pressure buildup refrigeration cycle apparatus has a low-pressure side compressor, a high-pressure side compressor, and a controller. The controller controls, for improving a COP, the low-pressure side compressor and the high-pressure side compressor in a COP improving operation mode in which a refrigerant discharge capacity of one of the low-pressure side compressor and the high-pressure side compressor is set based on a refrigerant discharge capacity of an other of the low-pressure side compressor and the high-pressure side compressor, when a required level of a refrigeration performance is low. The controller controls the low-pressure side compressor and the high-pressure side compressor in a high performance operation mode in which a refrigerant discharge capacity of the high-pressure side compressor is increased after increasing a refrigerant discharge capacity of the low-pressure side compressor, when the required level of the refrigeration performance is high.

The present invention relates to the fields of power electronics and electric motors, and describes a system for correcting harmonic content in power systems. The invention solves the space and weight problem, associated with the core of an inductor for correcting harmonic content, also providing performance advantages of electric motors, such as higher available voltage at maximum load and higher rotational speed at maximum load. The invention is particularly useful in refrigeration compressors.