Power conversion device with an intermediate capacitor and a smoothing capacitor

A power conversion device comprising:

• an input terminal to which a DC voltage is applied;
• a step-down device which has a first switching element and a first reverse-current blocking element and steps down the DC voltage applied to the input terminal;
• a booster to boost DC voltage, the booster including a second switching element, a third switching element, a second reverse-current blocking element, and a third reverse-current blocking element which are connected in series, the booster including an intermediate capacitor connected between a connection point between the second reverse-current blocking element and the third reverse-current blocking element, and a connection point between the third switching element and the second switching element;
• a smoothing capacitor which is connected in parallel to the booster and smooths the DC voltage boosted by the booster;
• a reactor provided between the step-down device and the booster;
• and
• a controller to control the booster and the step-down device, wherein
• the controller turns on the third switching element in at least a partial period of a period from start of charging until the intermediate capacitor is charged to a charge completion voltage of the intermediate capacitor, and the controller repetitively turns on and off the first switching element in a period until the smoothing capacitor is charged to a charge completion voltage of the smoothing capacitor.