Ui-Min Choi, June-Seok Lee, and Kyo-Beum Lee, “New Modulation Strategy to Balance the Neutral-Point Voltage for Three-Level Neutral-Clamped Inverter Systems,” IEEE Transactions on Energy Conversion, vol. 29, no. 1, pp. 91–100, Mar. 2014. -SCI > Paper

This paper proposes a new modulation strategy that balances the neutral-point voltage for three-level neutral-clamped inverter

systems. The proposed modulation replaces the P-type or N-type small switching states with other switching states that do not affect

the neutral-point voltage. The zero and medium switching states are employed to help the neutral-point voltage balancing. This

method little bit increases the switching events and output total harmonic distortion. However, this method has a strong balancing

ability at all regions. Further, it is very simple to implement in both space vector modulation and carrier-based PWM methods.

Simulation and experimental results verify the validity and feasibility of the proposed new modulation strategy