A Study on Common Mode Voltage Suppression of the Indirect Matrix Converter

• Main Authors: Wen-Mei Huang, 黃雯梅
• Other Authors: Tzung-Lin Lee
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/6k8ezv

碩士 === 國立中山大學 === 電機工程學系研究所 === 107 === Indirect matrix converter is an AC/AC converter which consists of the rectifier and the inverter stages in cascaded connection without dc-link capacitor. With the conventional modulation method, the inverter stage must be in zero vector states to conform zero current commutation when the rectifier stage commutates. However, switching in the rectifier stage cause large variation of the common mode voltage, and results in electromagnetic interference. The main possible solutions are avoiding the use of the zero vectors in the inverter stage and reducing the number of switchings. This paper will focus on analyzing the resulting common mode voltage with different combinations of modulation strategies implemented on both the rectifier stage and the inverter stage. In this thesis, the trapezoid modulation and the six-pulse method are used in the rectifier stage, continuous carrier based pulse width modulation and discontinuous carrier based pulse width modulation both with the fixed-slope carrier modulation method in the inverter stage. Finally, from experimental results, the maximum peak value of common mode voltage can be reduced about 37.8% compared to the conventional method. The functionality of the circuit is proved by the experiments of output load variation and output frequency variation.