Valuation Of Distribution Network Planning Including Distributed Generation Using Cosine Sorting Principle

Power distribution network is the major part of power system, often located in the terminate of power system, it’s closest to users and acts as the key segment of ensuring power supply quality and operating efficiency. In order to meet requirements of power supply enterprises and users and maximize their interest, the economic, reliability and security factors of power distribution network will be evaluated in the planning phase. Therefore, it’s quite significant to select an optimal solution via correct and reasonable evaluation methods.Based on preceding analysis, this paper mainly focuses on the evaluation of power distribution network planning solution with the distributed generation. Following issues are discussed in this paper.(1) The concept and characteristic of smart grid are introduced and considered; its difference with conventional power network is compared. The paper analyzed existing comprehensive evaluation of power distribution network planning and present status of evaluation of power distribution network planning of home and abroad. The massive connection of distributed power is considered to illustrate the characteristic of intelligent power network; the influence for power distribution network, features and classification of distributed power are discussed.(2) The principles established are based on power distribution network evaluation index system, economy, reliability, adaptability and security are 4 class A index, they are depicted through 10 class B index. Distributed generation investment cost, probability of grid-incorporating, anti-damage capability and extending factors are employed to express the characteristic of intelligent power network, every class B index can be acquired by examples, and finally attain the best solution in class A via comprehensive analysis.(3) After the planning of power distribution network, the way to evaluate, recognize and comprehend power distribution network plays a critical role. There are various kinds of evaluating scheme, they have their advantages in specific evaluation, but, in practical application, traditional scheme may be have the problem of strong- subjectivity and computational complexity. Aiming at these problems, the evaluation of power distribution network planning with cosine priortizing theory is employed to analyze examples. By establishing a multi-dimensional space and then putting the index to-be-evaluated and desired index in the space, cosine priortizing theory is a ranking scheme that calculates the cosine included angle value of index segment. The results of class B index of every solution are expressed in N row, representing the solution to-be-selected, the M columns represent the number of index, by standardizing this matrix, then an evaluation matrix is obtained; entropy weight method is taken to determine the weight so as to reduce subjective factors. In multi coordinates, the class B index of every solution represent a coordinate axis, so, N index segments to-be-evaluated are built in M dimension. By standardizing the evaluation matrix, the desired solution is obtained and then calculate the included angle between the index segments to-be-evaluated and desired solution. Finally, the optimum solution is reached by comparing cosine value of included angle.Cosine priortizing theory employed evaluation scheme can weaken strong-subjective of index weight and ranking complexity effectively, and are more flexible in strategic process, the validity has been verified by simulation, this research provide solutions for power distribution network planning staff and has practical engineering significance.