A Simple Current Sensorless Control Method for Boost PFC

For single-phase Boost power factor correction (PFC), current sensorless control could improve noise immunity while reducing cost and complexity. A simple and reliable single voltage loop current sensorless PFC control strategy is proposed, which does not rely on complex observers or mathematical models and provides an economical and efficient solution for consumer electronics products. Considering the conduction voltage drop and inductor resistance in real circuits, the duty cycle expression is derived using the fundamental equation of inductor voltage, which only requires the detection of input and output voltages. The duty cycle consists of a feedforward component and a control component. Delay compensation is further introduced into the control strategy to eliminate the effect of phase delay on input current distortion. To verify the feasibility of the proposed strategy, a 1.3 kW PFC prototype is designed and built, which can be widely adopted in medium and low power application scenarios. The experimental results show that the proposed strategy provides excellent performance under both steady-state and dynamic conditions over the full load range.