Abstract：Unbalance of dc-capacitor-voltage is an key technical problem of diode clamped multi-level inverter. In modulation of tradition SPWM and SVPWM, it produced neutral point current at DC part of multi-level inverter, the frequency of the current is treble of AC frequency. For avoiding the unbalance of capacitor voltage, the summation of charge injected in neutral point must be zero. This paper proposes a new modulation strategy, and it can be equivalent to VTSVPWM in diode clamped three-level Inverter and it can be applying in more level inverter. By injecting zero-order-voltage into modulation wave, this strategy can be equivalent to carrier modulation. This paper gives the simulation of Three-level Inverter and Five-level Inverter, and constructs the NPC three-level Inverter.
李国丽, 史晓锋, 姜卫东, 王红涛. 二极管钳位型多电平逆变器脉宽调制时电容电压均衡方法[J]. 电工技术学报, 2009, 24(7): 110-119.
Li Guoli, Shi Xiaofeng, Jiang Weidong, Wang Hongtao. Unbalancing Capacitor Voltage for Diode Clamped Multi-Level Inverter. Transactions of China Electrotechnical Society, 2009, 24(7): 110-119.
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2009, Vol. 24 
