Characteristics of Parallel-Module High Power-Factor AC-to-DC Converter System with Current-Balancing Controllers

Characteristics of parallel-module high power-factor AC-to-DC converter systems using current-balancing controllers are discussed. The current imbalance occurs when using the parallel connection of coverter modules. To solve this problem a current-balancing controller is utilized, and its effectiveness is confirmed by experiment. Two types of current-balancing controllers. i.e., Voltage reference control method and Current reference control method, are compared. Stability of the current-balancing control loop in the PFC converter system is investigated by using a small-signal model. As a result, the Current reference control method is stabler and has a faster transient response when compared with the Voltage reference control method