Distribution Network Reactive Power Coordination Optimization

Distribution network reconfiguration and capacitor optimal placement are the two main methods to optimize the distribution network. They both have the function to reduce the active power losses and improve nodes' voltage level. But the former is nonlinear combining optimal problem and the latter is nonlinear planning optimal problem. So it's prone to result in "combination exploration" and lower computational efficiency simply combining the above two means to carry on the coordination optimism of distribution network's reactive power.In this paper, TS algorithm is used to realize the network reconfiguration. By setting the properties of switches in each loop corresponding to the tie switch, the TS searching areas of each loop are made "independent" to each other. In this way the solution areas are made continuous and the dimensions of solution areas are decoupled by numbers of tie switch. Then the advantages for high optimal efficiency and global optimization of TS algorithm can be made good use to the proposed algorithm. To optimize capacitors placement in the distribution system for reducing power losses, the single capacitor compensation method is used to reduce the numbers of locations and to find the locations with best economic profits, meanwhile , the value of continuous variables is gained at the same time. When carrying on the distribution network reactive power coordination optimization, the discrete values of compensation capacitor are obtained using adaptive crossover step genetic algorithm on the basis of consideration of both network reconfiguration based on TS algorithm and compensation capacitors continuous variable optimization, accordingly the high efficiency and global optimal solution of network coordination reactive optimization are achieved.Corresponding software using C++ is programmed according to the algorithm mentioned above. The calculation to the typical IEEE examples shows that the proposed method is correct and effective.