Abstract: A high-frequency power supply device is provided with an AC-DC converter for converting an input from a three-phase alternating-current source into a direct current and a high-frequency amplifier including multiple FET elements and outputting a high-frequency alternating-current power, with the output of the AC-DC converter being directly input to the high-frequency amplifier, and further includes a phase conversion circuit for imparting phase differences to gate signals to be input to the multiple FET elements so as to offset fluctuation components included in the direct current. The device generates the high-frequency alternating-current power by converting the input from the three-phase alternating-current source into the direct current, directly inputting the direct current to the high-frequency amplifier, imparting the phase differences to the gate signals to be input to the multiple FET elements so as to offset the fluctuation components included in the direct current, and performing switching.

Abstract: In this power conversion device, a phase deviation of an output voltage due to a phase shift control is eliminated. The power conversion device according to the present invention converts DC voltage to AC voltage by phase-shift controlling the switching elements of a full bridge inverter. In place of a conventional method in which only one of the first and second legs of the full bridge inverter is phase-shifted, both legs are phase-shifted in opposite directions to each other to control an overlap angle at which the switching elements of the first and second legs of the full bridge are simultaneously brought into an on-state. The variation of the center phase of the overlap angle is suppressed by phase-shifting the first and second legs in the opposite directions to each other.

Abstract: In this power conversion device, a phase deviation of an output voltage due to a phase shift control is eliminated. The power conversion device according to the present invention converts DC voltage to AC voltage by phase-shift controlling the switching elements of a full bridge inverter. In place of a conventional method in which only one of the first and second legs of the full bridge inverter is phase-shifted, both legs are phase-shifted in opposite directions to each other to control an overlap angle at which the switching elements of the first and second legs of the full bridge are simultaneously brought into an on-state. The variation of the center phase of the overlap angle is suppressed by phase-shifting the first and second legs in the opposite directions to each other.