Two Stages Voltage Control Strategy using Cûk Topology with Three Phase Rectifier

A two stage rectifier using Cuk topology is proposed to supply variable output voltage having amplitude higher and lower than input voltage in high frequency applications. The main purpose of this work is to achieve a wide variation of output voltage using two stages at the same circuit for same and different load situation. For this reason in this work single stage circuit is modified to a two stage topology for getting better regulation. The principal features of the circuit include bidirectional power flow with low harmonics and improved power factor. The proposed rectifier also able to draw sinusoidal input current with power factor nearly unity where different single stages is operated from a single three phase balance source and a simple control circuit is introduced to generate the switching pulses. The analysis has been carried out to control the output voltage more widely compared to single stage Cuk regulated rectifier. This rectifier contains two active switches and simple fixed frequency PWM technique is used to control it. The operating principle, circuit diagram and experimental results are presented in this paper.