1 The Faculty of Engineering and Science, Aalborg University, VBN2 Department of Energy Technology, The Faculty of Engineering and Science, Aalborg University, VBN3 Power Electronic Systems, The Faculty of Engineering and Science, Aalborg University, VBN4 Ajou University
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.
I E E E Transactions on Energy Conversion, 2014, Vol 29, Issue 1, p. 91-100
Carrier-based PWM (CB-PWM); Multilevel; Neutral-point clamped (NPC) inverter; Neutral-point voltage balancing; Space vector modulation; T-type inverter