Application Study On Global Optimal Compensation Technology In 220V 400W PFC Boost Converter

Due to the application of nonlinear components,such as inductance,capacitance,power transistor and other devices,switching power converters behave as a strong nonlinear system,which mainly manifested as fast scale bifurcation and chaos.These serious impact the stable operation of the converters.The necessity of investigations on the stability control of the converters is high.Peak current mode controlled power factor correction Boost converter is studied in this thesis.Generating mechanisms of the fast scale bifurcation and chaos in the converter are found and effective control strategy is established.Main work and achievements in the thesis are as follows:a.Fixed slope compensation can effectively suppress the fast scale unstable behavior in the PFC Boost converter.The existence of the over compensation leads to dead time in the zero-crossing of input current and distortions of the input current.This decrease the power factor of the converter.Fixed slope compensation isn’t an appropriate choice.b.Account to the shortage of the fixed slope compensation,a global optimization compensation strategy has been proposed.Based on the theory of resonance parametric perturbation,compensation amplitude in the established strategy is dynamically adjusted in different periods of the input voltage.The converter operates steadily during the whole period of the input and standard sinuous wave in the input current is achieved.More important,unit power factor is got.The correctness and feasibility of proposed compensation strategy have been certificated by the simulation on 220V/400 W power factor correction Boost converter.The mathematical model of the reference current for the global optimization compensation strategy is derived and the design on the 220V/400 W power factor correction Boost converter is realized.Results indicate that the global optimization slope compensation strategy can effectively suppress the fast scale bifurcation and chaos,which overcomes the shortages of the traditional fixed slope compensation and unit power factor can be achieved.