Implementation of a Unifled Power Flow Controller for two Interconnected Solar Mini-Grids

Abstract

This project focuses on modelling a Unified Power Flow Controller (UPFC) to regulate power flow on the interconnection line between two solar mini-grids. As renewable energy sources become more prevalent, the interconnection of mini grids emerges as a strategic approach to enhance reliability, efficiency, and resilience in decentralized power systems. The UPFC, a flexible AC transmission system (FACTS) device, offers advanced capabilities in managing power flow, voltage stability, and reactive power compensation, making it an ideal solution for this application relative to its counterparts. The project involves the development of a detailed mathematical model of the UPFC, integrating its components-series and shunt converters-into the power system simulation. Using this model, we simulated various operational scenarios to analyze the impact of the UPFC on the power flow, evaluate the UPFC's ability to control active and reactive power flow between interconnected solar mini-grids with solar energy variability in one mini-grid. The simulations were conducted using DIgSILENT Powerfactory software. The results showed that the UPFC can perform help in mitigating reversal power flow and control the loading on the tie line, provide sufficient active power contribution and one hundred percent reactive power compensation relative the deficit on the demanding side of the line and thus improve the security and voltage stability during the intermittent behavior of the solar power plants.