A New Pulse-Width Modulation Algorithm for the Comprehensive Neutral-Point Balancing and Leakage Current Reducing in the Three-Level Transformerless Inverter
Wang Fusheng, Li Zhen, Fu Hang, Teng Yunliang
School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009 China
Abstract To reduce leakage current and balance neutral-point together, firstly analyzes the mechanism of leakage current of system and the effect of traditional modulation strategy on leakage current. And then based on the LMZVM carrier-based pulse width modulation, this paper proposes a carrier-based pulse-width modulation LMP/NSVM with zero-sequence voltage injection. Under the non-unity power-factor operation, this paper chooses the LMP/NSVM or LMZVM modulation strategy based on the dc side midpoint minimum charge. Compared with LMSVM modulation strategy, the NP potential is adjusted faster and the steady fluctuation is smaller using the LMP/NSVM proposed in this paper. The leakage current of the system is basically the same as the LMSVM and is better than the traditional SVPWM modulation strategy. And the algorithm from the angle of carrier-based pulse width modulation is extremely simple to realize. Eventually the effectiveness of the proposed modulation strategy is verified by comparing its results with traditional three modulation strategies.
Wang Fusheng,Li Zhen,Fu Hang等. A New Pulse-Width Modulation Algorithm for the Comprehensive Neutral-Point Balancing and Leakage Current Reducing in the Three-Level Transformerless Inverter[J]. Transactions of China Electrotechnical Society, 2017, 32(增刊2): 128-138.
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2017, Vol. 32 
