Boost PFC Control Research Based On Input-output Linearization

With the development of power electronic power converter technology,more and more power electronic devices are widely used in the household appliances?microgrids?rail traction converters and the field of military appliances such as aerospace power systems and aircraft carrier electromagnetic catapult.A large part of the power electronic devices need to connect with the grid through the rectifier consisting of diodes.The current in the grid after the rectifier will be seriously distorted to cause harmonic pollution to the grid,so how to suppress the power electronic devices produce a larger harmonic have become a hot topic of scholars.At present the most effective method is active power factor correction technology,the research mainly focuses on two aspects:the topology of the correction converter and the correction control strategy.The correction topology of this paper adopts the traditional Boost converter,the research focus is on its control algorithm.The traditional power factor correction control scheme based on double closed-loop PI is a kind of feedback control for the target and neglects some factors of the converter model,therefore,the control effect is still good at steady state,but the dynamic response speed is slowt when the load mutation or disturbance,and the current peak is very large when start the machine.Based on the shortcomings of the above control strategy,this paper uses a nonlinear control algorithm based on input and output linearization,insteading of designing the controller using the classical control theory by approximating the Taylor series expansion near the equilibrium point,the original nonlinear control system model is transformed into the new coordinate space by appropriate nonlinear coordinate transformation and state feedback,then the linear control system is designed by the classical control theory,Finally,the control law expression of the original coordinate space is deduced by the relationship between the new coordinate space and the original coordinate space.This method does not lose any information about the original nonlinear system,and thus becomes the focus of the study of scholars.In this paper,the input and output linearization method is applied to the power factor correction Boost converter.The PFC controller with constant power output and the PFC controller with constant voltage output are designed and deduced.The method can also be applied to the double Tube forward converter.This paper uses the professional power electronic simulation software PSIM to simulate the above-mentioned control algorithm.By analyzing the simulation waveform,it can be seen that the power factor correction control strategy based on input and output linearization method has the features of fast dynamic response speed and small peak current.In this paper,a 300W two-stage DC/DC converter is developed by introducing hardware and software design in the fifth and sixth chapters.The pre-stage is the power factor correction Boost source converter,and the latter is the double-tube forward load conversion device.Through the test on the experimental platform,the experimental waveforms corresponding to the simulation waveforms are obtained.It is further verified that the control strategy based on the input and output linearization method has the characteristics of fast dynamic response and strong anti-disturbance ability.