Model predictive control of a hybrid stacked multicell converter with voltage balancing and fault tolerance capability

Abstract

Abstract Due to the merits of low conduction losses and superior output power quality, a hybrid stacked multicell converter (HSMC) was put forward as a competitive alternative in the medium/low‐voltage high‐efficiency applications. A nine‐level HSMC (9L‐HSMC) can be seen as a combination of a five‐level SMC (5L‐SMC) and two‐level half‐bridge, and proper modulation and control strategy are essential for the HSMC to obtain the optimal output performance. This work develops a finite control‐set model predictive control (MPC) strategy for 9L‐HSMC to balance the capacitor voltages and maintain the desired outputs, rendering the absence of the linear regulator and pulse width modulation (PWM) modulator possible. The fault‐tolerant operation can also be achieved flexibly when open‐circuit faults occur at active bidirectional switches in the 5L‐SMC bridge, and the performance is verified by simulations. Finally, experiments under several typical operating conditions are implemented to verify the effectiveness of 9L‐HSMC with the developed MPC strategy.

Keywords

• Control of electric power systems
• Power system control
• Power convertors and power supplies to apparatus
• Optimal control