A Control Method for Bridgeless Cuk/Sepic PFC Rectifier to Achieve Power Decoupling

Bulky electrolytic capacitor is usually needed in bridgeless power factor correction rectifiers to buffer the double-frequency ripple power (DFRP). However, it reduces the system reliability and power density significantly. This letter proposed a control method to divert DFRP to the small energy transfer capacitor. Then, the bulky electrolytic capacitor can be replaced with a small film capacitor. The proposed method is realized by making the best of the existing switching states. Therefore, it needs no extra switches or energy storage components, which are usually required in other active power decoupling methods. The operating principle is explained, and a closed-loop control strategy is proposed. Finally, the effectiveness is verified by experimental results.