Heat pump device, heat pump system, and a control method of three-phase inverter

A heat pump device comprising:

• a compressor having a compression mechanism that compresses a refrigerant;
• a motor that operates the compression mechanism provided in the compressor;
• an inverter;
• and
• an inverter control unit that controls the inverter, wherein the inverter control unit includes
• a phase switching unit,
• an addition unit that changes a value n, which is an integer equal to or larger than 0, for every predetermined time, and outputs a phase θ3 obtained by adding a phase θplus, which is n times a size of 60 degrees, to the phase output from the phase switching unit,
• a voltage generation unit that generates a voltage command value based on the phase θ3 output by the addition unit and outputs the voltage command value, and
• a drive-signal generation unit that, based on an output from the voltage generation unit, generates drive signals corresponding to respective switching elements of the inverter, outputs respective generated drive signals to the corresponding switching elements of the inverter, and generates a high-frequency AC voltage in the inverter.

A heat pump system comprising:

• a heat pump device including a refrigerant circuit in which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are sequentially connected by a pipe;
• and a fluid using device that uses a fluid heat-exchanged with a refrigerant in the first heat exchanger connected to the refrigerant circuit, wherein
• the heat pump device includes
• the compressor having a compression mechanism that compresses the refrigerant,
• a motor that operates the compression mechanism provided in the compressor,
• an inverter, and
• an inverter control unit that controls the inverter, wherein the inverter control unit includes
• a phase switching unit that switches a phase θ1 and a phase θ2 different from the phase θ1 substantially by 180 degrees and outputs the phase, synchronously with a reference signal having a predetermined frequency,
• an addition unit that changes a value n, which is an integer equal to or larger than 0, for every predetermined time, and outputs a phase θ3 obtained by adding a phase θplus, which is n times a size of 60 degrees, to the phase output from the phase switching unit,
• a voltage generation unit that generates a voltage command value based on the phase θ3 output by the addition unit and outputs the command value, and
• a drive-signal generation unit that compares the voltage command value output from the voltage generation unit with the reference signal to generate drive signals corresponding to respective switching elements of the inverter, outputs respective generated drive signals to the corresponding switching elements of the inverter, and generates a high-frequency AC voltage in the inverter.

A control method for an inverter in a heat pump device that includes

• a compressor having a compression mechanism for compressing a refrigerant,
• a motor that operates the compression mechanism provided in the compressor, and
• an inverter, wherein
• the inverter control method comprises:
• a phase switching step at which a phase θ1 and a phase θ2 different from the phase θ1 substantially by 180 degrees are switched and output, synchronously with a reference signal having a predetermined frequency;
• an adding step at which a value n, which is an integer equal to or larger than 0, is changed for every predetermined time, to output a phase θ3 obtained by adding a phase θplus, which is n times a size of 60 degrees, to the phase output from the phase switching step;
• a voltage generating step at which a voltage command value is generated based on the phase θ3 output at the adding step and output;
• and
• a drive-signal generating step at which the voltage command value output from the voltage generation step is compared with the reference signal to generate drive signals corresponding to respective switching elements of the inverter, respective generated drive signals are output to the corresponding switching elements of the inverter, and a high-frequency AC voltage is generated in the inverter.