Analysis and Suppression of Circulating Harmonic Currents in a Modular Multilevel Converter Considering the Impact of Dead Time

作者：Chen, Baichao^*; Chen, Yaojun; Tian, Cuihua; Yuan, Jiaxin; Yao, Xiu

来源：IEEE Transactions on Power Electronics, 2015, 30(7): 3542-3552.

DOI：10.1109/TPEL.2014.2346957

• Circulating harmonic currents
• dead time
• equivalent model
• excitation model
• insulated gate bipolar transistor (IGBT) voltage drop
• modular multilevel converter (MMC)
• open-loop control

This paper focuses on analysis and suppression of circulating harmonic currents in a modular multilevel converter (MMC) considering the impact of dead time in medium-voltage applications. A continuous equivalent model of the MMC containing two ideal transformer models is presented. Using this model, the impact of a harmonic voltage upon the dc side is analyzed and the production mechanism of circulating harmonic currents is elucidated. At the same time, the impact of dead time and insulated gate bipolar transistor (IGBT) voltage drop (DTVD) is studied, which indicates that capacitor voltages, output harmonics, and circulating harmonic currents are influenced. Based on this analysis, an open-loop control strategy to suppressing circulating harmonic currents caused by the output current and DTVD is presented. Finally, all these conclusions are verified using a simulation platform with 14 modules per arm fed by a 14-kV dc voltage source and a downscaled experimental platform with four modules per arm fed by a 560-V dc voltage source.

• 出版日期2015-7
• 单位武汉大学