Multi-objective Optimization Of SWISS Rectifier Based On Nsga-? Algorithm

Due to the continuous advancement of power electronics technology,the performance requirements of the system are constantly improving.It is no longer only a single pursuit of one of the performances.It requires high efficiency,and it also hopes to have a higher power density and a stable output voltage.However,There is generally a conflict between the various performances,so the use of advanced technology to improve the performance of power electronics has become a development trend.As a new type of three-phase rectifier,SWISS rectifier has the advantages of small switching loss,low current harmonic filtering distortion rate and unit power factor operation,etc.It has high research value.Therefore,this paper uses a non-dominated sorting genetic algorithm(NSGA-?)with an elite strategy to perform multi-objective optimization on the SWISS rectifier.First of all,based on the topology of the SWISS rectifier,this paper analyzes its working principle and modulation strategy in detail.By studying the current space vector modulation strategy,the minimum injection current ripple modulation scheme is selected from the two modulation schemes to calculate the voltage of each power electronic device,Current stress and corresponding duty cycle,so as to multi-objective optimization of SWISS rectifier.Secondly,due to the complex structure of the inductor,it is necessary to separately select the iron core and the magnetic core to analyze and calculate the power loss and volume of the inductor,and establish the loss and volume models of the output capacitor C,Diode,and IGBT.In this paper,NSGA-II is selected as the multi-objective optimization algorithm of SWISS rectifier,the decision variable was selected as the parameter of each component,and the constraint condition was the data of each component The upper and lower limits of the parameter and the unequal relationship of various parameters,and the objective function is defined as powerdensity,efficiency and output capacitance ripple,and the Pareto optimal frontier is obtained through MATLAB simulation,so as to select a reasonable plan according to the priority of the objective function,And finally determine the corresponding components.Finally,the PLECS software is used to perform thermal-electric simulation on the SWISS rectifier,and the heat loss is measured by the heat flow meter module to compare with the calculated total average loss of each IGBT and Diode,and the working temperature of the SWISS rectifier is measured.The parameters are selected through simulation results to optimize the overall performance of the rectifier.