Development of a half bridge circuit for decoupling second harmonic power in single phase system

This paper presents a suitable switching scheme in order to decouple second harmonic power in single phase systems. Single phase ac/dc or dc/ac systems are subjected to harmonic disturbance caused by ripple power with double line frequency. This issue can be eliminated by installing bulky electrolytic capacitors in dc link. But this could result in lower power density and reduction of lifespan. A symmetrical half bridge circuit that utilizes the dc link capacitors for absorbing ripple power is proposed in this paper. Two switches and a small filtering inductor are the additional elements in the circuit. By this method the capacitance can be reduced to one tenth. Simulation of the circuit in MATLAB is presented.