The Research Of Single-Phase Soft-Switch Active Power Factor Correction

Since sixty-seventy of twenty century, due to the use of the high powerful power electronic facilities, the use of the family electrical equipments and increasing of all sorts of nonlinear loads, the distortion of waveform in power system become more and more badly. The public power system was polluted seriously by harmonic. The power electronic facilities are the main polluting source. In order to improve the power circumstance, reactive compensation, passive and active power filter were often adopted. Now, improving the power factor of the power electronic equipments, reducing the distortion of input current waveforms is one of the most important techniques.The active power factor correction (APFC) equipment of switch power that adopts average current mode control was presented in this paper, according to plenty of literatures. UC3854 that adopt average current mode control and double loop control was used to decrease the pollution to the system and improve the power factor of the system. The ZVT soft-switching technique was applied into the equipment in order to decrease the cost of switch and improve the electromagnetism compatibility in the facilities. The auxiliary switch was used to achieve soft-switching function. The ZVT soft-switching technology makes the main switch works in zero-voltage transformation and the main diode switch zero-voltage off , decrease the cost of the switch and EMI in the equipment. This paper focus on the following works:The topology structure, control strategy and soft-switching technique of APFC were Collected and analyzed to obtain the perfect topology structure, control strategy and soft-switching technique for the APFC equipment of switching power. The APFC equipment for switching power and ZVT soft-switching circuitfor the APFC equipment were designed . The examination proved that the ZVT APFC equipment is valid in improving PF and EMC, decreasing the cost of power apparatus.