Research On Boost Power Factor Correction Circuit Based On One Cycle Control

Switch power supply is widely used for social production and life, it bringsconvenience as well as harmonic pollution into the power grid which has become a bigthreat to the normal operation of power system that has caused the world attaches greatimportance to it. Active power factor correction technology is a effective way to correctinput current waveform, restrain harmonic current and improve power factor, so it iswidely used in switch power supply. At present one of the research hotspot is the studyof control methods. One cycle control is a novel nonlinear pulse width modulationcontrol strategy with high control precision and fast response，it is a very promisingmeans of control.This paper choose power correction circuit in switch power supply based on thestructure of the Boost as the research object, select one cycle control as the controlmethod to carry out the following work: first, based on the analysis of comparison ofseveral main circuit topology and control methods, this paper carry on the theoreticalanalysis and circuit simulation of the one cycle control based on the boost power factorcorrection circuit. Mainly focusing on the comparison between the simulation of onecycle control and the average current control, the result shows that the response speed ofthe one cycle control is faster and the time that output voltage reach steady state isshorter. Second, this research selects a kind of ICEXPCS01series chips as the controller,introduces the design of a actual300W power factor correction circuit in details, givethe transformation equations and the related peripheral device parameter design of thevoltage loop and the current loop considering the stability of the circuit at the same time.In the design of main circuit the research complete the design of EMI filter circuit,rectifier bridge and diodes, choose diodes with SiC materials to reduce the circuit losscaused by the reverse recovery time, it may improve the power factor as well as theefficiency of the circuit. Third, because of the output of the traditional power factorcorrection circuit is constant, it may increase the switching loss (especially under lowvoltage) that affect the efficiency of the circuit at last. In order to solve the problem, theresearch make some improvement through selecting a external error amplifier take theplace of the chip’s internal error amplifier, then the feedback network’s voltagedistribution ratio is changed, these make the output voltage can follow the change of theinput voltage and is adjustable. It is not only good for reducing the PFC circuit’sswitching loss, but also can reduce the level of DC/DC circuit’s loss, improve theefficiency of the whole switch power supply circuit. Fourth, the test shows that theactual circuit gets the same results with the simulation. It means Boost active powerfactor correction based on one cycle control circuit can make the input current and theinput voltage waveform in phase and as sine wave by controlling the duty cycle,realized the function of the power factor correction, improve the waveform distortion,play a good inhibitory effect in harmonic. After the modification of the circuit, it canplay a good role in making the input voltage follow the input voltage and reduce theswitching loss, improve the efficiency of the circuit consequently.