Seiko Epson Corporation

Yasufumi Akagi

Tatsuya Shimoda

Norio Ito

A power converter/inverter system for a load comprises a converter circuit for converting an alternating current power input into a direct current power intermediate signal in response to a first PWM voltage. An inverter inverts the DC power intermediate signal into an AC power output in response to a second PWM voltage. A smoothing filter is arranged in series between a converter and the inverter for filtering the DC power intermediate signal. An instantaneous real power calculating circuit calculates an instantaneous real power (IRP) relative to the inverter and is determined by a torque current command value and a load angular speed signal. A converter controller controls the first PWM voltage of the converter in accordance of a combination a predetermined converter amplitude setpoint, a DC voltage present at the DC power intermediate signal, and the instantaneous real power product. An inverter controller controls the second PWM voltage of the inverter in accordance with the inverter amplitude setpoint and amplitude of the AC power output.

Power converter/inverter system with instantaneous real power feedback

A voltage PWM converter/inverter system comprises a converter for converting an alternating current power input into a direct current power output and inverting the direct current power output of the converter into an alternating current power output. A smoothing circuit is inserted between the converter and the inverter and an instantaneous real power calculating unit calculates an instantaneous real power for the inverter to provide an output comprising an instantaneous real power calculated value. The system includes a converter controller for voltage PWM control of the converter based on a set converter command value, a terminal direct current voltage value of the smoothing capacitor, and the instantaneous real power calculated value. The system further includes an inverter controller for voltage PWM control of the inverter based upon a set inverter command value and the alternating current power provided as a an output by the inverter.

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Nagaoka, Japan

Yasufumi Akagi