Optimization Study Of Reactive Power Compensation For Rural Medium-voltage Distribution System

Several kinds of sensible consumers are widely used in the electrical system. Generally, the power factors of these consumers are low. This causes a lot of reactive power in the power grids and affects the quality of power supply, especially the rural medium-voltage power grids. Because of the length of the transmission lines, the number of distribution transformers, strong load seasonality and time variability, the reactive power in the rural medium-voltage power grids is more evident. But this also brings a great potential of reducing the loss in the rural distribution system. Therefore, the optimization of reactive power is of great importance to improving the voltage quality and to reducing the line loss.In view of the serious reactive power loss in the rural medium-voltage power grids, this paper has emphatically studied the optimization of the reactive power compensation for the rural medium-voltage distribution system. Based on the characteristics of the rural medium-voltage distribution sysetm, under the constrained conditions of minimum line loss, voltage quality and economic consideration, a convenient and effective half-ergodic search algorithm intended to get the optimal reactive power compensation place and the optimal compensation capacity was introduced. The optimization software with VC6.0++, which is suitable for the optimization of the reactive power compensation for the rural single-supply distribution system, was developed. The optimal compensation place and the best compensation capacity can be getted when the corresponding network parameters and load parameters is inputted. This software was validated with a uniformed load system. The optimization method of reactive power compensation was applied to a 10kV rural distribution system and the optimal number, position and capacity of compensation devices under different constrained conditions, as well as the comparion results of line loss and comprehensive economic comparion before and after compensation, are obtained. The work of this thesis provides a scientific reference for the decision-making of the reactive power compensation for the rural distribution system.