The Study Of Distribution System Planning Considering Reliability Worth And Its Algorithm

In power systems, distribution networks are the parts connected with customers directly. How to plan distribution networks and get the balance between economy and reliability is a very important problem. In traditional distribution network planning, utilities only pay attention to minimize the investment and operation costs, but ignoring the effect of reliability on customers. Based on the cost-benefit analysis, this paper takes into account the reliability worth in distribution network planning and studies mainly on two problems: the optimal structure and the optimal switching device placement of distribution networks. Since both of them are non-linear combinatorial problems, the paper uses tabu search algorithm, which is one of the artificial intelligent algorithms, to solve the two problems. The following is the main contents:â‘  Design the AC-flow-based reliability assessment program of MV distribution networks. Considering the characteristic of distribution networks, the back/forward sweep algorithm is used for power flow calculation. The reliability calculation is based on sorting the fault type of each node. These are the basis of taking account of reliability worth in distribution network planning.â‘¡ A tabu search method of the optimal structure planning for distribution networks is studied. Firstly, the paper introduces the basic theory of tabu search. Then combined with the characteristic of distribution networks, the study focuses on how to improve the efficiency of tabu search. In the random search, if not improved, tabu search has a big probability of generating infeasible results. The paper takes some measures to make the result move in the feasible area, which avoids unnecessary judgement and calculation. In addition, other aspects of the algorithm are also studied. The test results of two sample systems have verified the feasibility and efficiency of the proposed algorithm.â‘¢ For the first time , tabu search is used to solve the optimal switching device placement problem. Switching devices play a key role in the reliability of distribution networks. The paper takes into account two kinds of switching devices and uses the designed algorithm to determine the number and the locations of them. The proposed algorithm is validated on two distribution test systems. In addition, the algorithm is also used to optimize the distribution network gained by the structure optimization algorithm. The network structure and the switch placement optimization is used for the distribution system planning respectively, which makes the final planned distribution network has a more reasonable reliability level...