778 | P a g e Improving Power Quality by UsingMC-UPQC

This paper presents a new Unified Power-Quality Conditioning System (MC-UPQC),capable of simultaneous compensation for voltage and current in multi-bus/multi-feeder systems. By using one shunt Voltage-Source Converter(VSC) and two or more series VSCs the configuration is made. The system can be applied to adjacent feeders to compensate for supply-voltage and load current imperfections on the main feeder and full compensation of supply voltage imperfections on the other feeders. The configuration will be designed as all converters are connected back to back on the dc side and share a common dc-link capacitor. Therefore, power can be transferred from one feeder to adjacent feeders to compensate for sag/swell and interruption. The proposed topology can be used for simultaneous compensation of voltage and current imperfections in both feeders by sharing power compensation capabilities between two adjacent feeders which are not connected. The system is also capable of compensating for interruptions without the need for a battery storage system and consequently without storage capacity limitations. By the simulation the performance of MC-UPQC as well as the adopted control algorithm will be illustrated