Control of Power at Weak-Grid Using Upqc

In this paper a compensation strategy based on a particular CUPS device, the Unified Power Quality Compensator (UPQC) has been proposed. A customized internal control scheme of the UPQC device was developed to regulate the voltage in the WF terminals, and to mitigate voltage fluctuations at grid side. The voltage regulation at WF terminal is conducted using the UPQC series converter, by voltage injection “in phase” with PCC voltage. On the other hand, the shunt converter is used to filter the WF generated power to prevent voltage fluctuations, requiring active and reactive power handling capability. The sharing of active power between converters, is managed through the common DC link. Therefore the internal control strategy is based on the management of active and reactive power in the series and shunt converters of the UPQC, and the exchange of power between converters through UPQC DC–Link