Sensorless induction motor drive using coupled inductor based three phase inverters for solar pumping applications

The conventional two-stage and Z-source inverters rely on the impedance network, have limited voltage gain and discontinuous input current and provide lower efficiency at higher duty cycles due to parasitic components. The innovative inverter significantly reduces system cost, complexity, power loss, and stress while achieving high voltage gain with continuous input current. The suggested topology ensures inherent shoot-through immunity, reverse recovery of diodes, enhanced reliability, and suitability for low-voltage renewable sources such as fuel cells and photovoltaic systems. Single-stage inverters are used for induction motor drives because they provide voltage boost and inversion with better input power utilization. To track the maximum power point (MPP) under partial shading conditions and rapidly changing solar irradiance, a Modified invasive Weed Optimization-based Perturb & Observe (MIWO-P&O) algorithm is employed to ensure optimal energy harvesting from the solar panels. The proposed sensorless drive combined with the feedforward term in the control scheme resulted in improved dynamics. The designed inverter and the proposed control scheme demonstrated better efficiency, higher voltage gain, optimal power from the PV array, and reduced switching stress compared to the existing single-stage inverters. Overall, the system offers a cost-effective and reliable solution for solar-powered applications. Analytical, simulation, and experimental results are presented to validate the system's performance under varying irradiance and load conditions.