Power converter and heat pump system provided therewith

A power converter comprising:

• a power conversion unit that performs power conversion for a three-phase alternating current output from an alternating-current power source;
• and
• a current compensation unit that supplies a compensating current to the alternating-current power source, the current compensation unit including
• a current compensation unit inverter including a plurality of switching elements,
• a current compensation unit capacitor connected between direct-current-side nodes of the current compensation unit inverter,
• a current compensation unit reactor connected between the alternating current side of the current compensation unit inverter and the alternating-current power source,
• a compensation controller that obtains an output voltage command value such that a harmonic component contained in a power-source current supplied to the power converter from the alternating-current power source is reduced by the compensating current, and
• a drive signal generator that generates, based on the output voltage command value, a drive signal usable to drive the switching elements by a two-phase modulation method,
• the current compensation unit inverter supplying, by switching operation of the switching elements, the compensating current to the alternating-current power source via the current compensation unit reactor, and
• Td≤(45.23/fsw−0.135)(1.48−0.048*Pmax), where
• fsw represents a carrier frequency employed for generation of the drive signal,
• Pmax represents a maximum input power of the power conversion unit, and
• Td represents a dead time for the drive signal.

A power converter comprising:

• a power conversion unit that performs power conversion for a three-phase alternating current output from an alternating-current power source;
• and
• a current compensation unit that supplies a compensating current to the alternating-current power source, the current compensation unit including
• a current compensation unit inverter including a plurality of switching elements,
• a current compensation unit capacitor connected between direct-current-side nodes of the current compensation unit inverter,
• a current compensation unit reactor connected between the alternating current side of the current compensation unit inverter and the alternating-current power source,
• a compensation controller that obtains an output voltage command value such that a harmonic component contained in a power-source current supplied to the power converter from the alternating-current power source is reduced by the compensating current, and
• a drive signal generator that generates, based on the output voltage command value, a drive signal usable to drive the switching elements by a three-phase modulation method,
• the current compensation unit inverter supplying, by switching operation of the switching elements, the compensating current to the alternating-current power source via the current compensation unit reactor,
• Lac≤16/Pmax, and
• Td≤(34.00/fsw−0.145), where
• fsw represents a carrier frequency employed for generation of the drive signal,
• Pmax represents a maximum input power of the power conversion unit,
• Td represents a dead time for the drive signal, and
• Lac represents an inductance of the current compensation unit reactor when the current flowing in the current compensation unit reactor is 0 A.

A power converter comprising:

• a power conversion unit that performs power conversion for a three-phase alternating current output from an alternating-current power source;
• and
• a current compensation unit that supplies a compensating current to the alternating-current power source, the current compensation unit including
• a current compensation unit inverter including a plurality of switching elements,
• a current compensation unit capacitor connected between direct-current-side nodes of the current compensation unit inverter,
• a current compensation unit reactor connected between the alternating current side of the current compensation unit inverter and the alternating-current power source,
• a compensation controller that obtains an output voltage command value such that a harmonic component contained in a power-source current supplied to the power converter from the alternating-current power source is reduced by the compensating current, and
• a drive signal generator that generates, based on the output voltage command value, a drive signal usable to drive the switching elements by a two-phase modulation method,
• the current compensation unit inverter supplying, by switching operation of the switching elements, the compensating current to the alternating-current power source via the current compensation unit reactor,
• Lac≤16/Pmax, and
• Td≤(45.23/fsw−0.135), where
• fsw represents a carrier frequency employed for generation of the drive signal,
• Pmax represents a maximum input power of the power conversion unit,
• Td represents a dead time for the drive signal, and
• Lac represents an inductance of the current compensation unit reactor when the current flowing in the current compensation unit reactor is 0 A.