Implementation of a fuzzy logic scheme for Q/V control in distribution systems

This paper presents a fuzzy connectionist scheme for reactive power/voltage control in distribution systems. Power loss and voltage sensitivities obtained at the end of the base case load flow are used to determine the dominant inputs to the fuzzy connectionist model. The interdependence between bus voltages and capacitor settings adds to the computational complexity. Based on physically justifiable assumptions, the capacitor problem is decoupled from the voltage regulator problem. The fuzzy inference system (FIS) provides rules for the two decoupled problems. The rules are adapted using a neural network. Adaptability of rules contributes to qualitative comprehension of the inference process by a human operator. The proposed scheme is implemented in an integrated environment involving ´C´ language and the fuzzy logic toolbox and GUI of MATLAB. ´C´ language is used for carrying the numerical computations in the calculation library. The programming and the window handling facilities of MATLAB and its built-in functions in the fuzzy logic toolbox are used to create the front-end for the FIS. A 30-bus test system is used to demonstrate the effectiveness of the above approach.