Current Phase Lead Compensation Control Strategy for CCM Totem Pole Bridgeless PFC circuit based on Error Current Analysis

Continuous conduction mode (CCM) Totem Pole bridgeless power factor correction (PFC) converters with the traditional average current control method cannot achieve unity power factor at light loads due to the limited gain of PI controller at low frequencies. In this paper, an error current analysis method is proposed, which divides the steady-state error between the reference current and the inductor current under PI control into two parts: tracking error and disturbance error. It shows that the disturbance error is the main reason why unity power factor cannot be achieved. The steady-state error is eliminated through the inductor voltage drop feedforward and the input voltage feedforward, and the capacitive current caused by the EMI filter is also compensated, so that unity power factor can still be maintained at ultra-light load. Finally, a simulation circuit of the Totem Pole bridgeless PFC is built to verify the correctness of the theory and the effectiveness of the control method.