POWER CONVERSION DEVICE, MOTOR DRIVE CONTROL DEVICE, AIR BLOWER, COMPRESSOR, AND REFRIGERATING AND AIR CONDITIONING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain a power conversion device capable of improving circuit performance when on-duty is limited.SOLUTION: The power conversion device comprises: a three-phase rectifier; a step-up converter configuring a chopper circuit including a switching element; a switching control unit 10 for controlling the switching element; a smoothing capacitor for smoothing the output of the step-up converter; a rectified voltage detection unit for detecting a rectified voltage; and a bus voltage detection unit for detecting a bus voltage after smoothing. The switching control unit 10 is provided with a bus voltage control part 21 for calculating the on-duty of the switching element, an on-duty limiting part 22 for exerting control by limiting on-duty with a limiting value calculated on the basis of the rectified voltage and by varying a bus voltage instruction value on the basis of the rectified voltage, and a drive pulse generation part 23 for generating a drive pulse to open or close the switching element on the basis of the limited on-duty.