Optimal reactive power and voltage control for distribution system involves the installation of fixed shunt capacitors and tap changing voltage regulators along distribution feeders. This can improve voltage profiles for all end-use customers and reduce real power losses. In this book, the fuzzy logic optimization technique is studied and applied to solve the capacitor allocation problem in radial distribution systems. Using voltage regulator for voltage control of radial distribution systems is also studied to allow more loss reduction and to improve the whole system voltage profile. The applicability of the fuzzy logic technique in the field of capacitor placement problem is discussed. Modifications are made to existing fuzzy membership functions to obtain better results. Also, an approach using tap-changing voltage regulators is applied to maintain the voltage profile on a general radial distribution system within a pre-specified bandwidth. In addition, the action of the regulators is studied to provide the best possible profile while maximally decreasing system losses; this is done by controlling the regulator tap positions.

Thermal generation scheduling is considered as one of the most important power system operational planning problems. The scheduling problem consists of two main parts; the economic dispatch problem and the unit commitment problem (UCP). The former belongs to nonlinear programming problems while the later is a combinatorial optimization problem. Dynamic economic dispatch problem (DEDP) is a special type of the generation scheduling problem in which all the units are considered online during the entire scheduling horizon. In this book, Hopfield Neural Network (HNN) is applied to solve the generation scheduling and the DEDP. A detailed study of the effect of the HNN parameters on the solution quality of EDP including transmission losses is made. The most appropriate values of the parameters are tuned. A new algorithm is proposed to eliminate the gap between the solution obtained by HNN and the actual solution. Three software packages are developed under the MATLAB(r) platform to solve EDP, ramp rate constrained DEDP and UCP. To demonstrate the effectiveness of the proposed algorithms and enhancements, several test systems reported in literature, with different complexities, are solved.