An Auxiliary Link Based on Flyback Circuit with Voltage Spike Suppression for Single-Phase Isolated Full-Bridge Boost PFC

An effective auxiliary link to suppress voltage spike is proposed and investigated in a single-phase isolated full-bridge boost power factor correction (PFC) converter, by which the voltage spike in the primary side of power transformer led by leakage inductance can be suppressed obviously, and the absorbed energy are controlled to be transferred to the output side through a flyback converter parallel with the clamp branch capacitor, improving system reliability significantly. The constructions of the auxiliary link are composed of one diode, one capacitor, and a flyback converter. With the help of the added energy path, the lower voltage stress of full-bridge switches can be achieved. Experimental results show that this auxiliary link have a good effect on reducing the voltage spike on a laboratory-made prototype.