Current Zero-Crossing Prediction Based Critical Conduction Mode Control of Totem-Pole PFC Rectifiers

Last updated on Mar 25, 2023

Drawn by Mingde

A novel current estimator is proposed for CRM control. The behaviors of the estimator considering the nonlinear output capacitance of switching devices are modeled and analyzed;
No current sensor, ZCD circuit, or ZVS-catch circuits are required. This reduces the component count of the peripheral circuits and the resistive losses in the power circuit;
To improve the prediction performance, a disturbance damping control is proposed to mitigate the variation of inductance and parasitic resistance.
The proposed current estimator provides information on both the instant current and average current. The noisy CRM current signal is excluded from the control loop;
High power factor and high efficiency can be realized simultaneously. Valley-switching and zero-voltage switching are achieved;
The proposed concept is naturally compatible with high-frequency GaN devices.

Publications