Practical aspects of the unity power factor isolated three-phase rectifier based on the Scott transformer

In this paper, the unity power factor isolated three-phase rectifier based on the Scott transformer is analyzed. This topology presents a Scott transformer for galvanic isolation and uses instantaneous average current control. Models for proper design of the current and voltage loops are obtained by two methods. Using these models, reference current phase-shifting is analyzed and implemented. The use of a common voltage control loop for both boost PFCs, in order to equally distribute the total power between them, is discussed. A design procedure for the boost inductors and the Scott transformer, based on switching functions and the αβ transformation, is presented. Simulation and experimental results of a 12 kW laboratory prototype are presented and compared.