Some Studies Based on Red, Load Modeling, Line Outage using Voltage Stability Analysis

D.V.N.Ananth Member, IEEE VITAM College of Engg. Visakhapatnam, India.
Manuscript received on July 01, 2012. | Revised Manuscript received on July 04, 2012. | Manuscript published on July 05, 2012. | PP: 147-155 | Volume-2, Issue-3, July 2012. | Retrieval Number: C0725052312 /2012©BEIESP
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Abstract: There are many methods for overload relieving which have been reported for determining a secure operating point. Most of these methods use conventional optimization techniques, which are generally time–consuming from a computation point of view, especially for large systems. Further the conventional optimization technique updates all the controllers for most of the operating conditions. Under emergency conditions the operator, has to make quick decisions, with little concern for the theoretical optimality of the operating point and also the operator cannot move all the controllers to different settings within less time. In this context a simplified approach has been proposed in this paper for security oriented power system operation. The contribution of each generator for a particular overloaded line is first identified, then based on Relative Electrical Distance (RED) concept the desired proportions of generation for the desired overload relieving is obtained. Then based on the Generation Shift Sensitivity Factor (GSSF) concept the desired proportions of generation for the desired overload relieving is obtained. An attempt is also made to curtail the number of generators to be rescheduled based on GSSF for overload relieving Results obtained for network overload alleviation of 5 bus meshed system, IEEE 30-bus New England system are presented for illustration purposes. The change in load sharing and generation scheduling was examined when the slack bus was changed, generator node changed and placed in the midpoint of the system, increase in generator number, load modeling was calculated. For all the above cases the voltage stability indices (Ve, Lindex and MSV) were calculated, recorded and then compared for best performance to the previous cases. The generation scheduling was determined with line outage and subsequent load shedding.

Keywords: Relative Electrical Distance, Generation Shift Sensitivity Factor, Congestion, Load modeling, slack bus, load sharing, power flow analysis, optimal power flow.