A Modified Level-Shifted PWM Strategy for Fault-Tolerant Cascaded Multilevel Inverters With Improved Power Distribution

作者：Kim Seok Min^*; Lee June Seok; Lee Kyo Beum

来源：IEEE Transactions on Industrial Electronics, 2016, 63(11): 7264-7274.

DOI：10.1109/TIE.2016.2547917

• Cascaded H-bridge multilevel inverter
• fault tolerance
• level-shifted pulse width modulation
• neutral shift

To increase the fault tolerance for cascaded H-bridge multilevel inverters (CHMIs) based on level-shifted pulse width modulation (LS-PWM), a modified LS-PWM method is proposed for the inverters operating under faulty conditions. To cover both open-and short-device fault cases, two types of switching scheme are included in this PWM method. With this PWM method, the neutral shift can be applied as fault-tolerant control for CHMIs based on LS-PWM. Finally, three-phase-balanced line-to-line voltages and currents with minimum harmonic distortion are produced for the inverter with disabled power cells. In addition, this LS-PWM method has the capability to improve power distribution among the H-bridge power cells under the faulty conditions. Simulation and experimental results show that the proposed PWM method performs satisfactorily to achieve fault tolerance.

• 出版日期2016-11