Research on improved nearest level modulation strategy for modular multilevel converter
Sun Fan1, Wang Jinmei1, 2, Lu Ya’nan1
1. School of Physics and Electronic-Electrical Engineering, Ningxia University, Yinchuan 750021; 2. Key Laboratory of Ningxia Electric Power and Energy Security Autonomous Region, Ningxia University, Yinchuan 750021
Abstract The quality of the output waveform is reduced when the traditional level modulation is suitable for multilevel, high voltage, and low level. Based on the limitations of the traditional modulation method, the latest level modulation is improved. When the step wave is generated, the deviation of the independent variable is added, and the modulation wave and the step wave deviate, so that the output level of the system is doubled, and the total harmonic distortion THD value is reduced. Finally, the MMC simulation model is built in Matlab/simulink. The simulation results are compared with the output harmonic level generated by adding different deviations, and the optimal deviation is obtained, which verifies the correctness of the method.
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2019, Vol. 20 
