Damping potential of single-phase bidirectional rectifiers with resistive harmonic behaviour

To reduce the voltage distortion in a distribution network, parallel (shunt) harmonic impedances (SHIs) can be strategically positioned in the network. However, to avoid the additional cost of adding SHIs to the distribution network, the SHI function can be implemented as a secondary function of convertors connecting loads or generators to the mains. A control strategy for a single-phase bidirectional full-bridge AC-DC convertor is proposed. This control strategy allows a fixed resistive impedance to be programmed for harmonics, independent of the direction of the fundamental power flow. Hence, the bidirectional rectifier obtained behaves, as a secondary function, like a resistive SHI, providing damping for resonances and resulting in an overall improvement of the voltage distortion in the distribution network. The theoretical results obtained are verified by using an experimental test setup. The superior damping potential of the experimental bidirectional rectifier with the proposed control scheme is demonstrated by a comparison with experimental results previously obtained for ´classical´ control schemes.