Adaptive Fuzzy Logic Controller for Static VAR Compensator (SVC) in PV/Wind Hybrid Systems

Abstract

The increasing integration of photovoltaic (PV) and wind energy into modern electrical grids has introduced significant challenges in maintaining voltage stability and reactive power balance due to the intermittent nature of renewable energy sources. Conventional PI controllers used in Static Var Compensators (SVCs) have limited adaptability under rapidly changing operating conditions. This project proposes an Adaptive Fuzzy Logic Controller (FLC) for SVC to provide intelligent reactive power compensation and maintain stable grid voltage in PV/Wind hybrid systems. The fuzzy controller processes voltage error and change in voltage error through a set of predefined linguistic rules to generate appropriate control signals for the SVC. Based on these signals, the SVC injects or absorbs reactive power to regulate the grid voltage effectively. The proposed system offers faster dynamic response, reduced voltage overshoot, shorter settling time, improved power factor, and lower Total Harmonic Distortion (THD) compared to conventional PI-based methods. The controller is suitable for real-time implementation using microcontrollers such as ESP32 or Arduino, making it an efficient solution for future smart grid applications.

Introduction

The text presents an intelligent reactive power compensation system designed to improve voltage stability and power quality in hybrid renewable energy systems integrating solar and wind power. The intermittent nature of renewable energy can cause voltage fluctuations, poor power factor, increased Total Harmonic Distortion (THD), and reduced grid stability. Conventional compensation methods and fixed-parameter PI controllers often struggle to respond effectively to rapidly changing generation and load conditions.

The proposed system combines a Static Var Compensator (SVC) with an Adaptive Fractional-Order Proportional-Integral (AFOPI) controller to dynamically inject or absorb reactive power and maintain stable voltage. A Genetic Algorithm is proposed for optimizing controller parameters, while fuzzy logic is also included for online adaptation. An ESP32 microcontroller monitors voltage, current, power factor, and reactive power, and zero-crossing-synchronized thyristor firing enables controlled switching of the compensation equipment.

The system operates by continuously measuring the bus voltage, comparing it with the reference value, determining the required reactive power compensation, and controlling the thyristors through isolated gate drivers. This feedback process enables the SVC to respond to changes in renewable generation and load demand.

The main objectives are to improve voltage regulation, reduce overshoot and settling time, enhance power factor, minimize harmonic distortion, and increase overall grid stability. The proposed system is intended for applications in microgrids, distributed renewable energy installations, and industrial smart grids.

Conclusion

The scope of this research includes the modelling, design, implementation, and performance evaluation of an Adaptive Fractional-Order PI controlled Static Var Compensator for intelligent reactive power compensation in hybrid solar photovoltaic and wind energy systems. The proposed architecture consists of an ESP32-based digital controller, zero-crossing detection circuitry, synchronized thyristor firing unit, Static Var Compensator, voltage and current sensing circuits, power factor measurement, and Genetic Algorithm-based adaptive controller optimization. The developed controller continuously monitors electrical parameters including voltage, current, reactive power, and power factor while dynamically controlling thyristor switching to inject or absorb reactive power as required. The Adaptive Fractional-Order PI controller continuously adjusts compensation performance through online Genetic Algorithm optimization, enabling improved voltage stabilization during fluctuating renewable generation and varying load conditions. System performance is evaluated through simulation and experimental analysis using parameters such as voltage regulation accuracy, overshoot, settling time, power factor improvement, Total Harmonic Distortion reduction, and reactive power compensation efficiency. The proposed system is intended for hybrid renewable energy plants, industrial power systems, microgrids, distributed generation networks, and smart grid applications.

References

[1] Hamid Rezaie, Mohammad Hossein Kazemi-Rahbar, “Enhancing voltage stability and LVRT capability of a wind-integrated power system using a fuzzy-based SVC”, Engineering Science and Technology, an International Journal, vol. 22, Issue 3, pp. 827-839, June 2019. [2] Qutob, Subhi ; Ghattas, Ahmad ; Shaaban, Mostafa F.,” A Fuzzy Logic Based Static VAR Compensator For Wind Farm Voltage Stabilization”, 2024 6th International Youth Conference on Radio Electronics, Electrical and Power Engineering (REEPE), Moscow, Russian Federation, id.98, 29 Feb. 2024 - 2 March 2024. [3] Mohamed, Moayed, Ahmad, Hasnain, Alghaythi, Mamdouh L., Alshammari, Meshari S., Abdul-Hamid Shaban, Mohamed, Youssef Abdel-Hamid Hegazy, Hossam, Ahmed, M. M. R, ” Improved Control Approaches for Dynamic Voltage Restoration in Doubly Fed Induction Generator-Based Wind Turbines”, IEEE Access, Volume 14, pp. 10245-10261, 2026.

Copyright

Copyright © 2026 Dr. S. P. Ashtankar, Sanskruti Khapekar, Sakshi Bagde, Krishna Landge, Pranjali Kale. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.