Harmonic Current Analysis and Modulation Method Influence for Test Platform of Modular Multilevel Converter
The test platform of modular multilevel converter is an important means for the equivalent test of electrical stress test of power modules.In this paper,the generation mechanism of harmonic current is analyzed based on the topology and the modulation method.Then,the analytical expressions of the current ratio among the DC component,second harmonic,third harmonic and fundamental component by the fixed and average modulation are studied.At last,the harmonic current suppression method based on average modu-lation is proposed.The simulation platform in Matlab/Simulink is set up to compare and analyze the model-ling accuracy and control performance of the two methods.The results show that the difference between the analytical expression and simulation results of the two methods is less than 7.9%,which verifies the correct-ness of the theoretical analysis.Compared with the fixed value method,the average value method can effec-tively reduce the second harmonic current by 50%,which verifies the effectiveness of the proposed method.
万方数据
维普
