Vijayan J. Thottuvelil

An improved high-efficiency rectifier for telecom applications

A rectifier circuit architecture for achieving a power train conversion efficiency greater than 92% for a 12 kW rectifier for telecom applications is described for a design for a 380/480 V three phase AC input utilizing semiconductor devices with commonly available breakdown voltages is presented, including predicted and laboratory measurements of power train efficiency. An averaged model of the power train is developed in conjunction with a description of the control strategy.

Improving THD in single-phase high-power-factor rectifiers

The EMI filter capacitor connected across the input after the bridge rectifier in single-phase high-power-factor converters increases the total harmonic distortion (THD) of the input current waveform. Several schemes are described which use feedforward of the rectified input voltage waveform to reduce this THD without destabilizing the current-control loop of the switching power converter employed to shape the input current.