The Control Method in Synchronous Frame for DVR to Mitigate the Balanced and Unbalanced Voltage Sag/Swells Phenomenon in Power Network

Abstract

Nowadays great attention is paid to the problem of power quality. With the modern equipment, their operation is very sensitive to the quality of the power supply. When the power quality is not guaranteed, such as a nonstandard voltage, current or frequency, which will damage the equipment or the equipment will operate improperly. One of the basic problems here is Sag/Swells voltage. To solve this problem, the dynamic voltage Restorer (DVR) is put into use in the power distribution network. DVR will reduce or add the voltage in series with supply voltage through injection transformer to correct the amplitude, voltage phase and harmonic components into line. This paper proposes a control method for the DVR based on space vector control, with two feedback loops according to voltage and current. The authors use independent control methods, separation of components of direct and reverse in d-q Synchronous Reference Frame for DVR. This method has effectively controlled for the voltage sags and swells phenomenon in balanced and unbalanced. The research results are simulated and verified on Matlab - Simulink software.