HYBRID MODULATION METHOD TO REDUCE ZERO-CROSSING CURRENT OF TOTEM-POLE PFC CONVERTER

Tóm tắt

Nowadays, Totem-pole PFC power factor correction converters are widely used in many fields, notably in electric vehicle charging stations because of their ability to transmit power in bidirectional. The principle of this converter is similar to the traditional Boost PFC topology, which does not include a bridge rectifier, so the performance is significantly improved. The lack of a bridge rectifier leads to the control of switching devices is often based on the sign of the grid voltage, this modulation method is called Unipolar. However, the input current of this converter spikes whenever the input voltage crosses zero, which is considered an inherent characteristic of this topology. To eliminate this current spike phenomenon, a new modulation method was introduced called hybrid modulation. The main point is based on switching from unipolar to bipolar modulation whenever the input voltage crosses zero, thereby eliminating the current spike. A 4kW, 220VAC, 400VDC Totem-pole PFC circuit is simulated by using PSIM 9.1 software to obviously indicate the advantages of this modulation method