Development of Generalised Integrator with a Feedback Loop Based Dynamic Voltage Restorer for Fast Mitigation of Voltage Sag/Swell

Power-electronic converter-based device called the Dynamic Voltage Restorer (DVR) is intended to shield delicate loads from supply-side voltage perturbations. It is connected in series to the distribution feeder and has the ability to generate or absorb real and reactive power at its AC terminals. This work presents the use of a control scheme based on Generalized Integrator with a Feedback Loop (GIFL) gain choosing technique for the purpose of fast voltage sag/swell detection to enable the DVR to carry out a fast and effective voltage compensation in power distribution system. This helps in significantly reducing the impact of voltage sag/ swell and in turn improve the power quality of the system. Two scenarios were used to analyze the effectiveness of the developed technique: incorporation of voltage sag and swell independently on the distribution system. The results obtained showed that the distortions introduced to the system as a result of the sag and swell was significantly reduced. The results obtained from the developed scheme was further compared with that obtained when the conventional DVR was used in mitigating the voltage sag and swell using total harmonic distortion (THD) as performance metrics. All modelling and analyses were carried out using MATLAB 2019 software