Load bus voltage control using Fuzzy Logic under N-1 transmission line contingency

The voltage control problem is generally difficult because of the large scale and non-linear characteristics in power systems. Based on the power system status, the reactive power and voltage control is required to make the correct decision in order to get the system back to an acceptable operating state. For this purpose we have developed in this paper an algorithm based on Fuzzy Logic in order to control the VAR resources, transformer tap changer and PV pus voltage in a power system under abnormal and/or contingency operation to maintain the voltage at all buses within acceptable limits, when minimizing the number of control actions. The algorithm is iterative and designed to take advantage decoupling the load flow Jacobean matrix to decrease the computation time. The effectiveness of the developed algorithm is identified through its application to the IEEE 14 test system. The calculation results show excellent performance of the proposed method, in regard to computation time and quality of results.