Voltage Sag Control in Hybrid Systems Using SMES-DVR

Abstract

Hybrid renewable systems combining wind and photovoltaic (PV) sources often experience voltage sags that degrade power quality during grid disturbances. This paper proposes a Fuzzy Logic Controller (FLC)-based Dynamic Voltage Restorer (DVR) integrated with a Superconducting Magnetic Energy Storage (SMES) system for rapid voltage sag mitigation. The system is modelled and simulated in MATLAB/Simulink under symmetrical fault conditions. Simulation results demonstrate that the FLC-based SMES–DVR effectively restores the load voltage with minimal overshoot and oscillations, while also providing a faster response and improved stability compared to conventional DVR approaches.

Introduction

Hybrid renewable energy systems combining solar PV and wind power offer sustainable electricity but are prone to voltage sags caused by faults or sudden load changes. These sags can damage sensitive equipment and destabilize the grid. Dynamic Voltage Restorers (DVRs) mitigate sags by injecting compensating voltage, and their performance is enhanced when integrated with Superconducting Magnetic Energy Storage (SMES) for rapid power support. Traditional DVR control strategies may struggle with nonlinearities and fast disturbances, prompting the use of Fuzzy Logic Controllers (FLCs) for adaptive and robust voltage regulation.

This study models a hybrid PV–wind system with an SMES-assisted DVR controlled by an FLC in MATLAB/Simulink. Simulations under symmetrical (12% and 25%) and asymmetrical voltage sags show that the fuzzy-controlled DVR rapidly restores load voltage, reduces ripples, and improves stability compared to conventional DVR control. The results confirm that the SMES-DVR with fuzzy logic provides faster, more reliable compensation, ensuring stable power delivery in hybrid renewable energy networks.

Conclusion

The fuzzy logic simulation results demonstrate that the DVR–SMES system outperforms both PI- controlled and non-fuzzy setups. With fuzzy logic, the recovery time decreased from 0.040–0.055 s (PI) to 0.020–0.030 s, and the injected voltage decreased from 60–78 V to 30–42 V. This reduced the amount of work needed to compensate by almost 40%. Ripple levels also fell by 65–70%, yielding smoother voltage restoration near the nominal 330 V. Overall, fuzzy logic enables faster recovery, lower energy demand, and improved voltage stability, providing a more effective solution for sag mitigation in hybrid renewable systems.

References

[1] Chen, X., Li, Y., and C. Wu, J. (2018). Integration of superconducting magnetic energy storage with dynamic voltage restorers for enhanced power quality in distribution systems. International Journal of Electrical Power & Energy Systems, 100, 178–187. [2] Singh, R., C. Ghosh, A. (2019). Fuzzy logic-based dynamic voltage restorer for power quality improvement in distribution networks. IEEE Transactions on Power Delivery, 34(3), 1210–1218. [3] Al-Shetwi, A. Q., Hannan, M. A., Jern, K. P., Alkahtani, A. A., C Abas, A. E. (2020). Power quality challenges of grid-connected wind and photovoltaic energy systems: A review and solutions. Renewable and Sustainable Energy Reviews, SS, 150–163. [4] Patel, M., Sharma, P., C Verma, R. (2021). The study proposes a dynamic voltage restorer that utilizes superconducting magnetic energy storage and a fuzzy logic controller to compensate for voltage sag. Energy Reports, 7, 4567–4576. [5] Kumar, P., Singh, B., & Verma, R. (2017). The study conducted a performance evaluation of the Dynamic Voltage Restorer (DVR) for voltage sag mitigation using a PI controller. International Journal of Electrical Power and Energy Systems, 9, 111–12.

Copyright

Copyright © 2025 Prasanna Koraboina, Sharma K.V., Naik M.T.. 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.