Design and simulation of quasi-z source integrated multilevel inverter for grid connected systems

This thesis focuses on implementing a quasi-z-source integrated five-level inverter (QZSI) in a grid-connected single-phase system, specifically examining its operation when interfaced with a fuel cell as the DC source. QZSI, with its minimal switch count, presents an attractive solution for grid-tied applications by proficiently managing the power flow between the DC source, grid, and various loads. The modeling approach includes detailed simulation studies using MATLAB/Simulink to analyze the dynamic behavior of the QZSI system. This thesis thoroughly investigates the interaction between the QZSI and load variations under different operating conditions. Simulations cover scenarios where the fuel cell power is either below or above the load conditions, and when the system operates solely in the grid mode or in the inverter mode. The performance of the QZSI in terms of efficiency and voltage regulation was evaluated by considering variable load conditions. This detailed examination allows for an accurate assessment of the real-world power management performance of QZSI technology. This thesis contributes significantly to the overall understanding of QZSI technology by demonstrating its potential for integrating renewable energy sources and providing grid support. Simulation results show that the proposed system configuration is feasible and effective, with the QZSI delivering a high efficiency and low THD under varying load conditions.