Modeling and Analysis of High Frequency Magnetic Link-Based 11kVAsymmetric 21 level Inverter for Solar Photovoltaic Systems

Abstract

This paper presents a high-temperature superconductor (HTS) based high frequency magnetic linked three-phase twenty-one-level 11kV asymmetric multilevel inverter for grid integrated solar photovoltaic system. The proposed topology uses the identical cascaded H-bridge seven-level inverter with a triangular voltage sequence for generating desired voltage levels. In addition, a low-frequency modulation technique is developed to reduce the total harmonic distortion and the switching losses. A high-frequency transformer as the magnetic link is used to reduce the size and weight of the inverter. Simulation results reveal that the proposed topology features 61.76% of reduction of total blocking voltage and 78.90% of total harmonic distortion as compared to the conventional counterpart. The proposed topology also employs a reduced component count as compared with the existing twenty-one-level inverter topologies that are commonly used for various applications.