A Review on Modelling & Simulation of Three Phase Dynamic Voltage Restorer (DVR) using Proportional- Integral (PI) Controller

Abstract

Sensitive loads in power system require a special protection against sag/swell, flickering, harmonics and notching in power supply voltage which can be economically achieved by the dynamic voltage restorer (DVR). In this paper, a Proportional- Integral (PI) controlling method is proposed to generate instantaneous compensating voltage by DVR against disturbances. PI controls the loop mechanism by feedback. It basically changes the proportional and integral constants according to feedback and give possible output to meet the criteria. So, this controller is general enough to handle sag, swell and harmonics with acceptable total harmonic disturbance (THD). Simulation results are obtained using MATLAB/SIMULINK. The disturbances are generated by a programmable supply source. DVR is connected at point of common coupling (PCC) in series with load and supply system. Because the injected voltage is in quadrature with the feeder current, a DVR, supported by capacitor, does not need any active power during steady-state operation.