A power conversion apparatus is provided in a rotary electric machine, converting a power between a DC power source and the rotary electric machine having a multiphase winding. The power conversion apparatus includes: a plurality of switching modules each having a switching element for performing switching to control a current direction of a current flowing from the DC power source to the winding; a plurality of capacitor modules each having a capacitor that suppresses high frequency oscillation occurring on the current due to the switching operation; a positive side conductor connected to a positive electrode of the DC power source; and a negative side conductor connected to a negative electrode of the DC power source.