Cooperative fuzzy logic-based on-load tap changer control system and photovoltaic smart inverter control for voltage regulation in high penetration distribution networks

Introduction. The integration of photovoltaic (PV) systems into the conventional power system is one of the most promising approaches for efficiently meeting increasing energy demand. Problem. The increasing installation of PV systems makes significant challenges for voltage regulation due to non-continuous generation and two-way power flow. A conventional on-load tap changer (OLTC) control system, designed for operation in unidirectional power systems, cannot ensure voltage quality at all buses with high PV penetration. Goal. To develop a cooperative voltage regulation strategy that uses a fuzzy logic controller (FLC)-based OLTC, together with the active and reactive power control capabilities of PV smart inverters, to improve voltage regulation in high PV penetration distribution networks. An intelligent FLC is used to determine the optimal OLTC tap position, thereby quickly addressing voltage regulation issues and reducing unnecessary OLTC tap operations. Methodology. This study models and analyzes a sample radial test system comprising loads, OLTC transformers, and a high-PV-penetration system using MATLAB/Simulink. FLC, which depends on constrained exhaustive search optimization, was designed to regulate the OLTC in response to load, PV penetration, and source voltage. This work dived into 4 scenarios. The first two scenarios included conventional OLTC control with and without a PV system. The third scenario included an intelligent FLC for the OLTC with a full PV penetration. The fourth scenario included FLC with optimal active power penetration and reactive power compensation of PV smart inverters. Results. Simulation results demonstrate the effectiveness of the proposed intelligent control approach in achieving better voltage regulation while maximizing the allowable PV hosting capacity. Scientific novelty. The combining optimization for PV penetration and reactive power compensation with optimal intelligent control of the OLTC. Practical value. This research offers a robust solution for voltage regulation issues in modern power systems. The intelligent system solves voltage problems and implements proactive corrective measures. References 37, figures 28.