Power conversion device

A power conversion device comprising:

• a power conversion circuit which has a switching element and which performs power conversion of input power through switching operation of the switching element and outputs resultant power;
• and
• a control device for controlling the power conversion circuit, wherein
• the control device includes
• a pattern generation unit for generating a frequency change pattern in which 2n switching frequencies f are shifted thereamong, n being an integer equal to or greater than 2, and
• a controller for generating a control signal for switching the switching element, by using the 2n switching frequencies f for respective different duration times in accordance with the generated frequency change pattern,
• the pattern generation unit includes
• a frequency determination unit which, using n first frequencies fc and a second frequency fdef smaller than a smallest one of differences among the n first frequencies fc, determines the 2n switching frequencies f which are generated by adding/subtracting the second frequency fdef to/from each first frequency fc so as to sandwich the first frequency fc, and
• a shift determination unit which determines a shift order of the 2n switching frequencies f so that a middle value between two switching frequencies f before and after shifting does not overlap a value of each switching frequency f, and
• the controller uses a carrier wave having each switching frequency f as a carrier frequency and changes each carrier frequency in synchronization with upper peaks or lower peaks of the carrier wave.