Load flow, voltage stability & short circuit analyses and remedies for a 1240 MW combined cycle power plant using ETAP

Abstract

Load flow, voltage stability & short circuit analyses of a power system are essential for both design and operating stage performance monitoring and to ensure reliable grid operations by adequate protection scheme settings. In this research work, electrical model of a 1240 MW combined cycle power plant (CCPP) is developed on Electrical Transient Analyzer Program (ETAP) and load flow, voltage stability & short circuit analyses are performed. Effect of power grid voltage instability on system buses of the power plant is evaluated. Using load flow analysis that exploits Newton-Raphson algorithm, buses operating at under voltage due to power grid voltage instability are identified and their voltages are improved according to given voltage constraints that are based on buses criticality with respect to loads. On-load tap changers and reactive power compensation are used to improve steady state voltage stability. Optimal position for capacitor banks placement and number of capacitor banks are suggested by using optimal capacitor placement module of ETAP. The results of short circuit analysis are compared with short circuit current values experienced by the power plant sources. Consequently, favorable results have been accomplished through ETAP for all power system analyses.