To simplify compensation control for simultaneously performing series compensation and parallel compensation of three phases.

A power conversion controller includes a power supply-side converter circuit 40 having an R-phase input, an S-phase input and a T-phase input as AC input terminals connected to an AC power supply 1 and converting power inputted from the AC input terminals into DC, and a load-side inverter circuit 50 having a U-phase output, a V-phase output and a W-phase output as AC output terminals, converting DC outputted from the power supply-side converter circuit 40 into AC, and outputting it from the AC output terminals. A leg where two switching elements having inverse conduction functions are connected in series via a series connection point is provided. In the power supply-side converter circuit 40 and the load-side inverter circuit 50, three legs are connected in parallel. The power supply-side converter circuit 40 and the load-side inverter circuit 50 share one leg. Thus, the number of legs required for the structure of the power conversion controller can be reduced and a circuit can be simplified.