Efficient operation of Z-source integrated coupled inductor Cuk converter with optimised PI control for HRES microgrid environments

In response to the global shift towards sustainable energy, this research introduces a modern grid system integrating Photovoltaic (PV) array, Doubly Fed Induction Generator (DFIG) based wind turbines and battery storage to enhance system reliability and environmental sustainability. A key challenge addressed is the fluctuating output voltage of PV systems under varying environmental circumstances. To overcome this, a novel Z-source integrated coupled inductor Cuk converter is proposed, which combines the strengths of Z-source and coupled inductor topologies for improved voltage regulation and power quality. Additionally, a Rat Swarm Optimised Proportional-Integral (RSO-PI) controller is developed to ensure accurate and robust converter control, drawing on swarm intelligence for efficient parameter tuning. The proposed system exhibits a superior efficiency of 97.3%, reduced switch and diode stress, and low input current ripple compared to conventional converter designs. Simulation results using MATLAB further confirm the controller’s effectiveness, with the RSO-PI achieving the fastest convergence and best transient response including a rise time of just 0.04 s and steady-state error as low as 0.097%. This integrated approach significantly improves conversion efficiency, stability, and response time, making it a promising solution for future renewable-integrated smart grids.