Compact Switched-Capacitor Boost Active-Neutral-Point-Clamped Multilevel Inverter

Active neutral point clamping (ANPC) and switched-capacitor (SC) concept has clearly improved the application potential of multilevel inverters (MLIs) in photovoltaic systems. ANPC feature assist in reduction of the leakage current that is generated due to the common-mode voltage and SC feature assist in significant voltage boosting that is required matching the inverter output-grid voltage. Such combinational MLIs proposed recently suffer from the requirement of large number of components and voltage stress is very high. This paper proposes a compact 11-level ANPC MLI (CANPC MLI) using single input source. It can be designed for both single-phase and three-phase without using additional sources. The capacitors are charged in such a way that 11-level output with 2.5 times voltage gain is achievable across the load. Voltage balancing is not a concern as the series-parallel charge balancing principle is well-utilized. The structural analysis is presented in detail. A detailed comparative analysis is carried out with existing 11-level MLIs to justify the novelty of the proposed MLI. Finally, simulations are carried out under several dynamic operating conditions and results are illustrated to justify the voltage balancing and voltage boosting ability of the proposed CANPC MLI.