PSO-Based Online PI Tuning of UPQC-DG in Real-Time

Abstract

Power quality is critical in ensuring the efficient operation of electrical systems, and Unified Power Quality Conditioners with Distributed Generation (UPQC-DG) systems play a vital role in mitigating power quality issues such as voltage sags, swells, harmonics, and flicker. Proportional-integral (PI) control UPQC-DG systems are crucial for maintaining power quality by stabilizing the DC link voltage, which is also essential for the seamless integration of distributed generation into the power grid. Effective PI control ensures minimal voltage fluctuations and rapid response to disturbances, thereby enhancing overall system reliability and efficiency. However, traditional PI tuning methods, like the Ziegler-Nichols (ZN) approach, often fail to provide optimal performance under dynamic conditions in such complex converters. To address these limitations, this paper presents an innovative approach for real-time tuning of PI controllers in UPQC-DG systems using Particle Swarm Optimization (PSO). The primary objective is to dynamically optimize the PI controller parameters to enhance the stability and performance of the DC link voltage under varying operational conditions. The proposed method was validated in a real-time simulation environment using the OPAL-RT 4512 platform. The results demonstrate the PSO-based method's superior ability to reduce steady-state errors and enhance dynamic response as well. This study underscores the potential of PSO for real-time adaptive control, providing a robust solution for maintaining high power quality in UPQC-DG systems and improving the stability and reliability of distributed generation systems.