A Novel Seven-Level Hybrid-Clamped (HC) Topology for Medium-Voltage Motor Drives

This letter proposes a novel seven-level (7L) hybrid-clamped converter, which has competitive performance and lower device count compared to existing topologies. It can easily balance the floating capacitor voltage at the switching frequency, and therefore ensure low capacitor voltage ripples even under very low fundamental frequencies. Both multipulse diode front-end and active front-end structures can be used with the proposed 7L converter, where the 7L active front end has the ability to balance the dc-link capacitors. The proposed 7L converter is very suitable for medium voltage drives (4.16 to 6.6 kV) that feature low costs, high-performance, and low-speed operation capability. Simulation and experiment results are obtained to verify the feasibility of the proposed topology.