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.