Research On Reactive Compensation Configuration Optimization With Harmonic Consideration In Distribution Network

Reactive compensation configuration optimization of distribution network is an effective measure to ensure security and economy of distribution network. Optimal reactive compensation configuration could effectively improve voltage level, decrease network loss, and increase power factor. However due to the widespread use of nonlinear equipment in the distribution network in recent years, harmonic pollution in the distribution network is increasing. The harm of harmonic to distribution network is very great, it affects seriously safety of distribution network, economic and reliable operation of electrical equipment and distribution network. Therefore study on reasonable al ocation of reactive compensation in distribution network under condition of harmonic distortion has special significance. It not only make compensation to the best effect of loss reduction, but also restrain the harmonic which avoids harmonic amplification or resonance so that influence safety operation of distribution network.This dissertation devotes to the correlative problems of reactive compensatio n configuration optimization in distribution network, including the study on effective algorithms of fundamental and harmonic flow calculations for distribution network, research on particle swarm optimization algorithm and tis improvement, research on modeling and solving algorithm of reactive compensation configuration optimization in distribution network, and verify the effectiveness and practicability of the optimiza t io n model and solving method in actual distribution network. The main work of this dissertation as follows:Firstly, this dissertation analyzed comprehensively the harmonic source models and typical harmonic flow calculations, and found that the calculation time of those existing harmonic flow calculation methods would increase obviously with distribution network scale increases. Put forward a kind of distribution network harmonic flow calculat io n algorithm which derived from distribution network fundamental flow calculat io n algorithm to solve this problem. This algorithm can figure out quickly and effective ly harmonic indexes of distribution network, and it laid a good foundation for reactive compensation configuration optimization in distribution network with harmonic consideration.Secondly, the author comprehensively analyzed basic PSO algorithm's thought, main parameters, convergence, advantages and disadvantages, and pointed out the defects in convergence and search precision of the standard PSO algorithm, then put forward the ideas of PSO improvement: modifying the value of key parameters of PSO algorit hm according to the convergence conclusion,and it has great improvement in terms of convergence performance and search accuracy compared with standard PSO algorithm.Thirdly, the reactive compensation configuration optimization model was established according to the actual situation of distribution network. The objective function of the optimization model are the minimums of the power active loss and capacitor investment cost respectively. The constraint conditions of the optimiza t io n model are made of system flow constraint, controlled variable constraint, and status variable constraints. The improved PSO-based algorithm proposed on the premise of compensation configuration optimization model had established.Finally, calculating the optimization results of IEEE 11-bus distribution network and Sichuan Guangyuan actual distribution to verify the validation and practicability of the optimization model and solving method. The optimization results indicated that the optimization model and solving method was available and practical.