Control of Bi-directional Converter for charge-discharge battery using PI With Modified PSO

Increasing demand for renewable energy integration and efficient energy storage solutions have highlighted the critical role of battery. Batteries serve as essential components in energy systems, storing excess power for various applications, and backup power solution. However, achieving control for battery is challenging due to stability of charge and discharge, changing load condition, and battery state of charge fluctuation. To ensure efficiency of battery, accurate control of bi-directional converter is required. Bi-directional Converter facilitates the power flow required for this process but controlling battery charge discharge accurately. Among the many control methods, the Proportional-Integral (PI) controller is widely used for regulating the charge-discharge operation. However, selecting optimal PI parameters is non-trivial and greatly affects systems performance. This study proposes an enhanced control strategy for a bidirectional converter using PI controller optimized by a modified Particle swarm optimization (PSO) algorithm. The proposed method incorporates a dynamic re-randomized mechanism to overcome premature convergence in a standard PSO, improving its ability to escape local minima. Additionally, a penalty function is applied to restrict the search within a defined stable range for the controller gains. The performance of the system is evaluated based on the Integral of Time-Weighted Absolute Error (ITAE) criterion to minimize transient and steady-state errors. Simulation result using MATLAB/Simulink demonstrate that modified PSO-based PI controller significantly improves system performance-reducing overshoot, enchanting settling time, and maintaining stability under different operation modes (charge and discharge). This method offers a practical and efficient solution for optimizing converter control in battery-based energy storage systems.