VOL. 4, NO. 2, APRIL 2009 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences © 2006-2009 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com DYNAMIC COMPENSATION REQUIREMENT ANALYSIS FOR AN INDIAN UTILITY Anshul Chaudhary 1 , Vivek C. Niraj 1 , S. Prabhakar Karthikeyan 1 , R. Nagaraja 2 , I. J. Raglend 1 and D. P. Kothari 3 1 School of Electrical Sciences, VIT University, Vellore, India 2 Power Research and Development Consultants Private Ltd., Bangalore, India 3 VIT University, Vellore, Tamil Nadu, India E-Mail: anshul3144027@yahoo.co.in ABSTRACT This paper presents a technique to find out the suitable dynamic compensation requirement for an Indian utility i.e. Maharashtra region. The practical system considered was a part of western grid which is very critical for power evacuation from a major generating station. The objective of this paper was to increase the power flow in identified weak lines using dynamic compensation. As the variable capacitor does not suite economically, the option of using the series compensation which is used for reducing the angular separation and shunt compensation with Static VAR Compensator (SVC) was used for damping out the voltage oscillations at the receiving end is explored. The study result showed that the power flow could be increased considerably in the weak lines and also the system was stable in the steady state as well as in the dynamic conditions. Keywords: dynamic compensation, shunt compensation, static var compensation, sensitivity analysis, transient stability analysis. 1. INTRODUCTION Recent power systems are undergoing a profound transformation in the form of restructuring. Many private power companies have entered in to the power industry. This has resulted in complex operation and control of large interconnected grid systems. In this changing scenario, the primary challenge for power engineers is to efficiently control the active and reactive power flows in a specific transmission line or the corridor due to dynamically changing inter grid transactions. Control of power flows should be achieved without generation rescheduling or topological changes in order to enhance the power system performance [1]. Flexible AC Transmission systems (FACTS) controllers are proved to be very useful in achieving this and in addition these devices will also enhance the secured operation of power systems [2, 3]. Reactive power control has grown in importance for a number of reasons. First, the requirement for more efficient operation of power systems has increased with the price of fuels. For a given distribution of power, minimizing the total flow of reactive power can reduce the losses in the system. This principle is applied throughout the system, from the simple power factor correction capacitor used with a single inductive load, to the sophisticated large interconnected networks. Second, the extension of transmission networks has been curtailed in general by high interest rates and in particular cases by the difficulty of acquiring right-of-way. In many cases the power has been increased, requiring the application of reactive power control measures to restore stability margins. Third, the exploitation of hydropower resources has proceeded spectacularly to the point where remote, hostile generation sites have been developed. Inspite of parallel development of dc transmission technology, ac transmission has been preferred in many cases. The problem of stability and voltage control are identifiable as problems in reactive power control, and a wide range of different solutions has been developed, ranging from the use of fixed shunt reactors and capacitors, to series capacitors, synchronous condensers and modern static compensators. Fourth, the requirement for a high quality of supply has increased because of the increasing use of electronic equipment and because of growth of continuous-process industry. Among the family of FACTS controllers, SVCs are used in power systems for rapid control of voltage control at weak points in the network. By virtue of their ability to provide continuous and rapid control of reactive power and voltage, SVCs enhance several aspects of transmission system performance such as control of temporary over voltage, prevention of voltage collapse, enhancement of transient stability [4]. At the sub transmission and distribution system levels, SVCs are used for balancing the three phases of systems supplying unbalanced loads. They are also used to minimize fluctuations in supply voltages caused by repetitive-impact loads such as dragline loads of mining plants, rolling mills, and arc furnaces [5]. In this paper suitable dynamic compensation for the given system has been found out which will allow increasing the generation at Chandrapur in future and enhancing the power flow through the identified weak lines while maintaining the system stable from steady state as well as dynamic point of view. Suitable degree of series compensation has been found out using power flow analysis which will enhance the power flow through the identified weak lines, reduce the angular separation between sending end and receiving end and improve the dynamic stability of the system. Suitable amount of fixed shunt compensation has been found out using power flow analysis which will maintain the voltage profile almost constant at the point of connection. Sensitivity analysis of SVC was done to find out the most suitable parameters of SVC to be connected at receiving end. 19