A Novel Rectifier Topology with a Chopper Operating at the Line Frequency

Rectifiers, being highly non-linear loads, cause a lot of distortion in the input phase current and hence inject higher order harmonics in the grid that result in grid stability issues and poor power factor. Severity of the issues increases with an increase in power delivered to the load. This paper presents a comprehensive review of different rectifier topologies and highlights design trades off, and then presents a novel topology based on a bridge rectifier followed by a chopper operating at the line frequency. Simulation results show that input current THD reduces to 31.7% and 16.7% at the secondary side and the primary side of the transformer respectively and correspondingly input power PF is improved to 0.986. Compared to 12-pulse rectifiers, the proposed topology is highly compact and economical as it does not require additional phase shifting transformer, and gives the performance equivalent to the performance of a series connected 12-pulse rectifier. The proposed topology is superior to high frequency PWM based topologies as well for lower dynamic power loss and hence making it better suited for high power applications.