Three-phase front end converters and current control techniques for unity power factor

In recent years, an increasing portion of generated electrical energy is converted through rectifier, before it is used at the final load. These rectifier act as non-linear load on the power system which causes low input power factor and injects harmonics into the ac system. The harmonic content and low power factor at the supply side due to rectifier has been a great concern. In order to mitigate this problem several three-phase converter topologies are developed. In this paper various three-phase high power factor converters and also control schemes for low current distortion and unity power factor are discussed. Among the various topologies and control techniques discussed the Pulse Width Modulated (PWM) reversible rectifier with space vector based hysteresis current controller is identified as most suitable.