Principle Of Designing Slope Compensation In Peak Current Mode Controlled PFC Boost Converter

The topologies of power converter will be alternately changing due to its switching operation. Usually, switched-mode power converter can be taken as a time-varying nonlinear system. It can predicted that there inevitably exist a wealth of linear and nonlinear phenomena in its operation regime, such as periodic, quasi-periodicity, bifurcation and chaos, which makes the system difficult to work according to the desired requirements. The chaotic phenomenon in power electronic converters is a problem that might be important. On one hand, through researching chaos we will recognize the nature of power electronic converters and analyzes some previous unexplained phenomena, such as irregular electromagnetic noise, unstable working condition of the operating system; on the other hand, we can implement performance that the existing power electronic converter can not achieve. At the same time, the research of nonlinear phenomena in power electronic converters, also provides carriers and examples for the chaotic dynamics of nonlinear scientific study, it can promote the rapid development of nonlinear science.With the rapid development of power electronics technology, harmonic pollution caused more and more attention. Power factor correction (PFC) technology that can effectively restrain the harmonic pollution is becoming the focus of the researching in power electronics technology. In order to better design of PFC converter circuit parameters, we should further study the stability of PFC converter.This paper introduces the basic concepts of chaos, the working principle and researching methods of switching converters, the basics technology of power factor correction. Then we take the peak current mode controlled PFC Boost converter as a model, and analyzes its working principle and operation of the nonlinear phenomenon. The usual measure is to adopt slope compensation, so as to weaken or even eliminate this fast-scale instability. But in the practical application, the compensating slope is designed experientially, and over compensation can arise unpredictably. The consequence of over compensation is an increase of the THD (total harmonic distortion) of input current, which will also definitely decrease the power factor of the circuit. Owing to the above reason, in this paper we will carry out theoretical analysis for slope compensation in peak current mode controlled PFC Boost converter based on the bifurcation theory of nonlinear system, and explain the mechanism of designing slope compensation from the bifurcation control viewpoint. Accordingly, we achieve the general design principle assuring stable operation and simultaneously maintaining high power factor for PFC circuit.