Neutral-Point Potential Balancing Control Method with Accurate Zero-Sequence Voltage Calculation for Common-Mode Voltage Reduction

Traditional neutral-point (NP) potential balancing control methods based on zero-sequence voltage injection require polarity determination of modulation waves for duty cycle calculation, leading to computational complexity. This paper proposes a reference voltage decomposition-based method for accurately calculating zero-sequence voltage in two-level systems to achieve NP potential balancing. The zero-sequence voltage only needs to be calculated six times based on different sectors. Furthermore, by flipping the switching sequence of one phase, common-mode voltage (CMV) reduction can be simultaneously realized, reducing the CMV amplitude to half of the original value. Experimental results validate the effectiveness of the two proposed schemes.