A heat pump device includes a compressor including a compression mechanism that compresses a refrigerant and a motor that drives the compression mechanism, an inverter that applies a voltage for driving the motor, a converter that applies a voltage to the inverter, an inverter control unit that generates a driving signal for driving the inverter, and a converter control unit that generates a driving signal for driving the converter. The inverter control unit includes a heating-operation-mode control unit that controls a driving-signal generating unit such that the driving-signal generating unit outputs, as inverter driving signals, PWM signals for heating the compressor without rotationally driving the motor by feeding a high-frequency current that the motor cannot follow in a heating operation mode.

A filter and throttle unit for a scroll compressor. The filter and throttle unit includes a housing which has housing walls, an opening which acts as a throttle, and a filter element which is arranged within the housing walls of the housing. The opening is arranged in one of the housing walls.

The invention relates to a method for operating a compressor (100), wherein an ionic liquid (a) is used as an operating liquid, and wherein two different materials (c, d) of the compressor (100) are brought in contact with the ionic liquid (b) and form an electrochemical element. In order to partially balance a voltage (U) of the electrochemical element at the compressor (110), a counter voltage (U.sub.G) is applied. The invention further relates to such a compressor (100).

A filter and throttle unit for a scroll compressor. The filter and throttle unit includes a housing which has housing walls, an opening which acts as a throttle, and a filter element which is arranged within the housing walls of the housing. The opening is arranged in one of the housing walls.