Research On PFC High Efficiency Integrated Circuit And Design Of EMI Circuit

In order to improve power quality and reduce the pollution of harmonic currents to the power grid,Power Factor Correction(PFC)circuits had been widely used in various power electronic devices.This paper studied the PFC Boost circuit based on the main power supply of permanent magnet synchronous motor controller.In order to improve the operating efficiency of circuit and reduce influence of parasitic parameters,a scheme using an integrated PFC Boost circuit was proposed.The efficiency of the integrated PFC Boost circuit and the discrete PFC Boost circuit was compared and analyzed.The advantages of the integrate PFC Boost circuit was analyzed from the protection mechanism and the package effect.Furthermore,The Electromagnetic Interference(EMI)filter was designed and verified based on the PFC Boost circuit.Firstly,this paper analyzed the topology of various PFC circuits and its advantages and disadvantages.According to the actual application,the traditional PFC Boost topology was selected as the research object to improve its efficiency and suppress its electromagnetic interference.According to the current market conditions,the discrete PFC Boost circuits were widely used.Based on the discrete PFC Boost circuit,the key parameters were designed and analyzed.Futhermore,the design method of PFC inductor was optimized.The loss calculation of each component in the circuit was also given.The efficiency was calculated by theoretical derivation.Secondly,in order to pursue higher efficiency of PFC Boost circuit,this paper proposed an integrated PFC Boost circuit.The integrated PFC circuit in this paper used an intelligent integrated power module(switching device and power diode are integrated with the motor inverter part).Describe the advantages of the integrated PFC Boost circuit versus the discrete PFC Boost circuit.Futhermore,the loss of the circuit was analyzed and calculated,and the efficiency of the integrated PFC circuit was derived theoretically.Then,the propagation path of electromagnetic interference was analyzed for PFC Boost circuit in detail.A method of solving the mixed interference of the circuit was proposed.The common-mode and differential-mode equivalent circuit of PFC Boost circuit were derived.Calculated the transmission gain of the common-mode and the differential-mode interference voltage.The method of reducing common-mode and differential-mode interference in the circuit were given.In order to optimize the EMI filter,a more efficient common-mode inductor high-frequency fitting model was proposed for the high-frequency impedance characteristics of common-mode inductors.The model was verified by impedance analyzer and MATLAB calculation tool.The EMI filter was optimized based on this model.Finally,the experimental platform of discrete PFC Boost circuit and integrated PFC Boost circuit was built in this paper.The results show that the proposed integrated PFC Boost circuit had higher efficiency and better reliability.The optimized EMI filter was verified based on the experimental platform.The result proved the feasibility of the proposed high-frequency modeling method of common mode inductor.