Mitsubishi Electric Corporation

Takato Toi

Toshiyuki Fujii

Takuya Kajiyama

Takaharu Ishibashi

Hayato Takeuchi

An object is to obtain a power conversion device that can prevent ripple from increasing owing to change in switching frequency. A power conversion device includes: semiconductor switching elements connected between a DC voltage source and an output side, and connected in series to each other; a reactor; a control unit which controls a switching frequency of each semiconductor switching element; and a voltage detector, a voltage detector, and a current detector which respectively detect a voltage value of an input voltage, a voltage value of an output voltage, and a current value of an inductor current. Changing of the switching frequency and detection of the voltage value of the input voltage, the voltage value of the output voltage, and the current value of the inductor current are each performed at a timing that allows synchronization with a carrier.

Power conversion device with loss minimization and synchronized detection and switching frequency changing

A power conversion device includes: a power converter connected to an AC grid to which a load is connected; and a control circuit. The control circuit includes a harmonic compensation unit that includes a current command generation unit and a limit coefficient calculation unit and compensates for harmonic current contained in load current. The current command generation unit generates compensation current desired values for respective frequency components, and corrects the compensation current desired values using corresponding limit coefficients, to generate compensation current commands for respective frequency components. The limit coefficient calculation unit calculates each limit coefficient, on the basis of the compensation current desired value for each frequency component, and maximum voltage and maximum current that the power converter can output.

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Tokyo, Japan

Takato Toi