A Three-level Inverter Neutral Voltage Balancing Control Method
Owe to three-level inverter mature topologica! structure and low harmonic content of output voltage, it has been applied widely in large power and high voltage applications, but three-level topological structure leads to an inherent problem that is the neutral potential imbalance. This paper analyses the intrinsic causes in neutral voltage imbalance and presents the voltage balance method based on a hysteresis loop control. According to the different combinations of load current direction, the method controls two-capacitor voltage dynamically by adjusting the small redundant vectors and fully considering the effect of medium vectors on the neutral point potential balance. The paper analyses the switching states choice, the order of switch sequence and allocation of time in detail when the reference voltage vector falls into small triangle having one or two redundant small vector. Simulation and experimental results show that the control method can achieve a good neutral point voltage balance.
neutral potential imbalance hysteresis control neutral point voltage control current direction
Zhou Jinghua Liu Zhiqiang zhangxiaowei lizhengxi
Power electronics and motor drives engineering center, North China University of Technology, Beijing, China
国际会议
太原
英文
459-465
2011-02-26（万方平台首次上网日期，不代表论文的发表时间）