Static and dynamic response of a parallel-module high power-factor converter system with current-balancing controllers

Steady-state and dynamic characteristics of a parallel-module high power-factor converter system are discussed. The current imbalance occurs when using the parallel connection of converter 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 more stable and has a faster transient response when compared with the voltage reference control method.