Voltage Sag/Swell Compensation using Dynamic Voltage Restorer

With the increasing use of sensitive loads, power quality problem such as voltage sags, swells and harmonics are introduce into the distribution system. To overcome this power quality problems various custom power devices such as DSTATCOM, UPQC, and DVR etc. are used. Among this Dynamic Voltage Restorer (DVR) which is series connected power electronic based device is used in power distribution network. Dynamic Voltage Restorer (DVR) is a custom power device used to regulate the load voltage against the power quality problems. There are different control strategies are used for control of DVR based on compensation technique. In this book the reference voltages for dynamic voltage restorer (DVR) are generated using a control algorithm based on unit templates and instantaneous symmetrical component theory. These voltages, when injected in series with distribution system can tightly regulate the load voltage to the pre-fault value against any power quality problem in the source side. The voltage injected is in quadrature with the source current hence the DVR does not need any active power during steady state. The proposed control strategy for the control of capacitor support