Voltage Stability Compensation in Electronics –Saturated Network Using Unified Power Flow Controller

Abstract

Voltage stability is a critical aspect of power system operation, especially in networks with a high penetration of power electronic loads such as variable speed drives, converters, and renewable energy systems. These electronics-saturated networks often experience voltage fluctuations, harmonic distortions, and reactive power imbalances, which can lead to instability and reduced power quality. The Unified Power Flow Controller (UPFC), a key Flexible AC Transmission System (FACTS) device, offers a comprehensive solution to these challenges by providing simultaneous control of voltage, impedance, and phase angle in the transmission line. This paper presents an approach for voltage stability compensation in electronics-saturated networks using the UPFC. The shunt converter of the UPFC provides reactive power support, maintaining bus voltage levels and mitigating voltage sags caused by nonlinear electronic loads. Simultaneously, the series converter regulates line impedance and power flow, reducing line losses and improving load distribution. Additionally, the coordinated control of the shunt and series converters helps damp power oscillations and improve system resilience against sudden load variations. Advanced control strategies such as Proportional-Integral (PI) controllers, Fuzzy Logic Controllers (FLC), and Model Predictive Control (MPC) are discussed for optimizing the UPFC’s performance under varying load conditions. Simulation results demonstrate that the UPFC significantly enhances voltage stability, reduces harmonic distortion, and improves overall power quality in an electronics-saturated network. The proposed solution is suitable for applications in modern power grids, including industrial plants, electric vehicle charging stations, and smart grid environments.