Optimizing control of single-ended primary inductor converter integrated with microinverter for PV systems: Imperialist competitive algorithm

This article introduces a novel control strategy aimed at improving the efficiency and stability of grid-connected photovoltaic (PV) systems by enhancing the performance of the single-ended primary inductor converter (SEPIC) integrated with a microinverter. Traditional control methods often fail to optimize both grid dynamic response and power quality simultaneously, especially in response to changing environmental conditions like solar irradiance and load fluctuations. In contrast, this research focuses on a specific and deliberate strategy. The key innovation lies in the simultaneous multiloop optimization of the SEPIC–microinverter system using the imperialist competitive algorithm (ICA). This approach involves using ICA to adjust the parameters of the inner current loop (using P control) and the outer voltage control loop (using proportional integral (PI) control) of the SEPIC converter to maintain DC voltage regulation in PV systems. We argue that our ICA-integrated approach can overcome the limitations of traditional control techniques (such as classic PI tuning) and previous research that mainly focused on single-loop optimization or isolated component improvements. The results of our study demonstrate the significant benefits of this co-optimization. Simulation results from MATLAB/Simulink, with pulse width modulation (PWM) control, confirm that this co-optimization leads to substantial improvements compared to conventional systems and standard control methods: a 60% reduction in settling time during transients (from 1.5 to 0.6 s), elimination of overshoot (which was around 20% in the uncompensated system), an increase in attenuation from 0.19 to 0.47, and improved oscillation suppression.