Voltage sag and swell alleviation in distribution network using custom power devices; D-STATCOM and DVR

In this paper, an electromagnetic transient model of embedded Distribution Static Compensator (D-STATCOM) and that of Dynamic Voltage Restorer (DVR) are established in a state-of-the-art PSCAD/ETDMC environment. This is aimed at improving reliability and alleviating voltage sags and swell at load point in a distribution network. Sinusoidal Pulse Width Modulation (SPWM) is used to monitor the Voltage Source Converter (VSC) employed to monitor the operations of these Custom Power devices. An overview of D-STATCOM and DVR together with their basic configurations, mode of operations, functions and control scheme are reviewed. A test distribution network subjected to some disturbances; sensitive load variation and faults is developed and simulated with and without the controllers. The system´s response before and after introducing the controllers, clearly demonstrates their effectiveness and robustness in voltage stability and power quality control.