A Modified Active Neutral Point Converter for Isolated Power Supply Electric Drive Systems

Hybrid and Modular Multilevel converters are becoming an alternative to the conventional drive topology in industrial sector due to its reliability in operation, quality of output power, fault tolerant capability and flexibility in enhancement. However, the advancements of multilevel topologies in portable, isolated power supply electric system is immature due to the restriction of independent power sources. This paper proposes a multilevel power conversion concept employing a Modified Active Neutral Point Clamped Converter (MANPCC). The proposed system is designed for isolated power supply medium power electric drives where the number of DC power sources are restricted, i.e., for electric vehicles, portable cranes etc. The proposed topology has been analyzed, verified with Matlab/Simulink software and realized with a hardware prototype. MANPCC can generate voltage levels with low switching frequency and with reduced dv/dt. Inherent capacitor voltage balancing ability is another notable feature of the proposed system. A Phase Shift Carrier Based pulse width modulation strategy is used for implementing the topology.