Provided are a power conversion device, relating to control of detecting a bus current in operation, and capable of acquiring an average current through a small amount of calculation and being implemented by an inexpensive microcomputer. A variation in a winding current flowing through a multi-phase winding of an AC rotating machine, namely, a phase current, is small at a timing at which voltage vectors on both sides of an axis having a larger inductance out of d and q axes of the AC rotating machine are output. Thus, switching signals are generated at timings at which the voltage vectors on both sides of the axis having the larger inductance out of the d and q axes are output, and the bus current is detected in accordance with the switching signals, thereby acquiring a value close to an average of the winding current.