Modified control technique for improvement of DVR transient response

Dynamic Voltage Restorer (DVR), is widely used in distribution systems for protecting sensitive loads against voltage disturbances such as sag and swell. Proposing a DVR for effective voltage waveform improvement needs a very fast transient response. In order to improve DVR´s transient response in different working conditions, the effort should be put on its control technique. In this paper a closed multi-loop control method is suggested. The proposed method is verified for voltage waveform improvement during voltage sag occurred due to startup of a large induction motor and also during a three phase fault occurrence. Simulation results show the effectiveness of proposed control technique.