Power conversion device control device and power conversion device control method

A power conversion device control device for controlling, in time with PWM signals that are generated from duty command values and switching frequencies, a multi-phase inverter in which a plurality of half-bridge circuits each including one semiconductor switching element in an upper arm and one semiconductor switching element in a lower arm are connected in parallel, the power conversion device control device comprising:

• a carrier generating unit for outputting, for each of multiple phases, a carrier in a pattern that follows a carrier change pattern set so that switching processing in which a plurality of switching frequencies are switched sequentially is repeated for each repetition cycle, which is a reciprocal of a repetition frequency;
• and
• a PWM signal generating unit for generating the PWM signals, which are used for controlling the semiconductor switching elements as instructed by the duty command values, while sequentially switching from one of the plurality of switching frequencies to another for each phase separately, based on the carrier input from the carrier generating unit,
• wherein the carrier generating unit generates the carrier change patterns of the respective phases, which are defined by parameters of an average switching frequency, a spectral diffusion index, and the repetition frequency, so that at least the carrier change pattern of one phase differs from the carrier change patterns of the other phases.