Affiliation of Author(s):自动化学院
Journal:2018 IEEE TEXAS POWER AND ENERGY CONFERENCE (TPEC)
Key Words:PWM strategy unbalance phenomenon low switching frequency capacitor voltage balancing strategy
Abstract:Carrier phase-shift PWM strategy is widely used in the MMC system to satisfy the drive demands of numerous switches in submodules. However, an unbalance phenomenon in the submodules' capacitor voltages occurs when the PWM strategy is used in the system that has a low switching frequency, badly deteriorating the system working performance. This study first analyses the relation between the unbalance phenomenon, PWM strategy and switching frequency. The change trends of capacitor voltages in different submodules are then obtained to provide an accurate description for the cause of the unbalance phenomenon in a low switching frequency. Based on the analysis above, an improved capacitor voltage balancing strategy is subsequently proposed to effectively decrease the magnitudes of the unbalance phenomenon. The efficiency of the unbalance phenomenon in a low switching frequency and improved capacitor voltage balancing strategy are finally demonstrated via experiments.
Translation or Not:no
Date of Publication:2018-01-01
Co-author:Wang Chuyang,Jia Heping
Correspondence Author:Wang Chuyang,Xiao Lan
Date of Publication:2018-01-01