CONTROLLER FOR POWER CONVERTER

A power converter has a capacitor and a power conversion unit having a series-connected unit composed of an upper arm side switching element and a lower arm side switching element. The capacitor is connected in parallel with the serios connection unit. The power conversion unit supplies electric power to a motor. A controller for the power conversion unit has a frequency characteristics estimation part estimating frequency characteristics of a battery current of the battery when a current is flowing between the power convertor and the battery, a ripple current setting part determining a ripple frequency of a ripple current contained in the battery current based on the frequency characteristics of the battery current, and a control part performing a switching control of the switching elements based on the ripple frequency in order to generate the ripple current.