A New Method On Power Quality Evaluation Based On Principles Of Entropy

With the development of national economy and science and technology,the power customers, demand for power quantity and quality is becoming more and more eager, power quality synthesis evaluation has been paid more and more attention to by power utility and customers. In electricity market environment, the quantified description from power quality synthetic evaluation is a vital basis for power quality evaluation and electricity pricing. And in competitive electricity market,a logical evaluation on power quality is an essential prerequisite to establish a fair electricity market. Power quality is a synthesis of several indexes , according to the developmental need of the power quality evaluation, the concept of power quality comprehensive evaluation (PQCE)for regional grid has been used.The substation bus is regarded as the base for Power Quality Comprehensive Evaluation, and Flow chart of regional PQCE is designed in this paper. For avoiding uncertainness in optimization of projection pursuit and improving the efficiency of optimization, the bus PQCE can be picked-up in application of Projection Pursuit Evaluation model based on Maximum Entropy (ME-PP), the genetic projection pursuit method based PQCE constructed the projection function with the power quality indexes, and made the optimization by accelerating genetic algorithm. In order to react the power customers, subjective will, and as well react the objective reality which makes the weight can embody the character of the index's data,While the bus status is prescribed by expertise with the help of the principle of minimum relative information entropy, Combined Weighted method based on Status and Eigenvalue (CWSE) is put forward to determine the PQCE of substation, voltage degree, as well as entire gird.It has been proved that ME-PP decreases the uncertainty of projection and CWSE makes the regional PQCE objective, overall and reasonable.