Power factor correction and efficiency investigation of AC-DC converters using forced commutation techniques

In this paper the power factor and the efficiency of a suggested AC-DC converter topology is studied via Mathlab/Simulink simulation. This converter topology consists of four MOSFET elements in bridge form and: a) two antiparallel IGBT elements between the bridge and the AC grid, b) one MOSFET element between the bridge and the DC load. These switching elements control the conduction time intervals of the bridge by a hysteresis current controller in order to achieve an AC current waveform in phase with the AC voltage as well as a very low content of higher harmonics. This way the values of the power factor and the efficiency become very high (e.g. 0,98... 0,99).