A single-phase AC/DC electric power conversion apparatus includes an indirect matrix converter having an input interface to receive a first alternating current (AC) signal and an output interface to produce a second AC signal, where the first AC signal has a grid frequency. A transformer has a primary winding and an electrically isolated and magnetically coupled secondary winding. A coupling inductor is connected in series between the output interface of the indirect matrix converter and the primary winding. An H-bridge switching arrangement is connected to the secondary winding and produces an output signal having a DC component and at least one AC component. The at least one AC component has a second order harmonic of the grid frequency. An active filter reduces the second order harmonic AC component. A modular conversion apparatus for three-phase power replicates the single-phase apparatus as a module for each phase and omits the active filter.