A hybrid methodology for the development of intelligent voltage and reactive power control systems

The reactive power which is entirely different from frequency has local characteristics. In the past, it is managed by the manual operation in a local reactive power control station. Since coordination or integrated control was possible due to the recent advances in computers and communication networks, the hierarchical voltage control system, consisting of primary, secondary, and tertiary, has been already used in the real-life situations of developed countries. In this paper, the intelligent system, or expert system for the voltage and reactive power control will be displayed as a prototype that has a simpler structure in terms of MMI and database prior to the development of intelligent system for real-time control. This system makes fully use of the sensitivity matrix that is a numerical analysis technique of control equipment such as generator terminal voltage, shunt capacitor/reactor, transformer tap as well as the best-first searches to use sensitivity coefficients as the cost function, leading to the development of a hybrid type expert system. The intelligent system has been tested on IEEE 30-bus sample system, and test results applied to the test-bed would be really satisfactory at a steady-state level.