Reactive Power Optimization Of Distribution Network With Distributed Generation

As the problem of energy and environment is more and more serious,green and renewable energy has attracted more and more attention.Distributed generation has been more and more applied to power systemas a new technology which can make full use of new energy. Reactivepower optimization is an effective measure to improve the quality ofpower supply and enhance the security, stability and economy of thedistribution network; it has been studied as an important researchdirection. After DG accesses to the distribution network, DG not only hasa certain impact to the quality of power supply, but also affect thedistribution network planning, design, working, and so on. As a result, ithas important theory value and actual significance to research theproblem about reactive power optimization with DG.Firstly, several typical DGs are introduced, then the influence of DGon distribution network is analyzed, in addition, the paper focuses onanalysis of the influence of the capacity and location of DG on voltageand power loss of distribution network.Secondly, the calculate methods of power flow are concluded intraditional distribution network, the handling of different types of DG isanalyzed; then the power flow calculation and its advantages anddisadvantages are studied in the distribution network with DG.Thirdly, to overcome the problems of basic particle swarm algorithmsuch as premature, bad convergence precision, final slow convergencerate, a simplified particle swarm algorithm using dynamically changinginertia weight and learning factors is proposed. Inertia weight andlearning factors are dynamically changed in the algorithm so that it canadjust the global search ability and local search ability during searchingbest solution. The results show the proposed algorithm significantlyimproves the optimal performance of particle swarm optimization.Finally, a reactive power optimization mathematical model with DGis built up. The active power loss, the penalty functions including thevoltage exceeding and DG’s reactive power exceeding are taken intoconsideration. Three optimization algorithms applied for optimal reactive power is simulated on18-bus distribution system and IEEE33-busdistribution system. The results show that DG incorporated distributionnetwork reasonably and optimizing the reactive power of DG caneffectively reduce the active power loss, improve voltage quality andenhance the security, stability and economy of power grid. Besides, theresults demonstrate the proposed algorithm is effective and feasible.