A control strategy for a five-level double converter with adjustable DC link voltage

This paper proposes a control strategy of a three-phase five-level double converter for induction motor drives. The converter consists of the five-level rectifier, the DC link, and the five-level inverter. In this control strategy, the five-level rectifier fixes the DC link voltage at low value in the low-speed area and increases it in proportion to the motor speed in the high-speed area. The method will redress the imbalance of the generated losses at switching devices in the five-level inverter and reduce the generated losses. The performance of the control strategy is verified by experiment.