Research on zero-sequence signal of space vector modulation for three-level neutral-point-clamped inverter based on vector diagram partition

This paper proposes a novel method for analyzing the zero-sequence signal of three-level voltage-source inverter based on vector diagram partition. The inherent relationship between carried-based PWM and SVPWM is demonstrated. It is shown that the two method can worked equivalently through proper selection of active time for the redundant vector in the case of space vector modulation, or zero-sequence signal injections in the case of carried-based modulation. Furthermore, a novel balancing control strategy of NP potential is proposed based the zero-sequence signal injections. Both simulation and experiment result verify the effectiveness of proposed approach.