COMPENSATION OF VOLTAGE AND CURRENT IN MULTI-BUS/MULTI-FEEDER SYSTEM BY USING MC-UPQC Y.VIJAY KUMAR 1 , K. RAVICHANDRUDU 2 & P. SUMAN PRAMOD KUMAR 3 1 Department of EEE, Sri Venkateswara College of Engineering & Technology, Chittoor, Andhra Pradesh, India 2 Department of EEE, Krishnaveni Engineering College, Guntur, Andhra Pradesh, India 3 Department of EEE, CR. Engineering College, Tirupathi, Andhra Pradesh, India ABSTRACT This paper gives a unified power-quality conditioning system ,which is capable of simultaneous compensation for voltage and current in multi-bus/multi-feeder systems. From the proposed configuration, one shunt voltage-source converter (shunt VSC) and multi series VSCs are available. The proposed system can be applied to adjacent feeders to compensate for supply-voltage and load current imperfections on the main feeder and maximum compensation of supply voltage imperfections on the other feeders. In the proposed configuration, 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 other interruptions.The performance of the MC-UPQC as well as the adopted control algorithm is illustrated by simulation. The results are obtained in MATLAB/SIMULINK on a two-bus/two-feeder system show the effectiveness of the proposed configuration. KEYWORDS: Voltage Imbalance Power Quality (PQ), MATLAB/SIMULINK, Unified Power-Quality Conditioner (UPQC), Voltage-Source Converter (VSC) INTRODUCTION With increasing applications of nonlinear and electronically switched devices in distribution systems and industries, power-quality (PQ) problems, such as harmonics, flicker, and imbalance have become serious concerns. In addition, lightning strikes on transmission lines, switching of capacitor banks, and various network faults can also cause PQ problems, such as transients, voltage sag/swell, and interruption. On the other hand, an increase of sensitive loads involving digital electronics and complex process controllers requires a pure sinusoidal supply voltage for proper load operation. Power Quality Many industrial segments, is often enamored by the bells and whistles, colorful diagnostic displays, high speed performance, and levels of automation that can be achieved. Although these features and their indirectly related computer based enhancements are key issues to an efficient terminal operation, we must not forget the foundation upon which we are building. Power quality is the mortar which bonds the foundation blocks. Power quality also affects terminal operating economics, reliability, our environment, and initial investment in power distribution systems to support new installations. To quote the utility company newsletter which accompanied the last monthly issue of my home utility billing: ‘Using electricity wisely is a good environmental and business practice which saves you money, reduces emissions from generating plants, and conserves our natural resources.’ As we are all aware, c ontainer crane performance requirements continue to increase at an astounding rate. Next generation container cranes, already in the bidding process, will require International Journal of Electrical and Electronics Engineering Research (IJEEER) ISSN 2250-155X Vol. 3, Issue 3, Aug 2013, 247-266 © TJPRC Pvt. Ltd.