Research On Substation Life Cycle Cost Modeling And Its Risk Assessment Methods

With the sustained economic growth and social power consumption continuing to increase, in order to guarantee the power supply reliability and power quality, the amount of electricity investment is more and more, which is promoting the rapid advance of the construction of the substation. The traditional substation management focuses on the immediate interest, lacking of the long-term benefits, which cannot meet the new level of substation management. Substation life cycle cost modeling not only achieves the substation economic and technical evaluation in power grid planning stages, avoiding the blindness of constructing a new substation, but also has certain reference value of making decision to optimize the LCC in the substation operation, maintenance and other aspects which improves economic efficiency.Substation life cycle cost is based on the reliability and life management, which attributes substation entire life time cost(from initial investment, operation and maintenance, failure and the retirement during the entire process) to the total cost. The core objective is to make substation LCC optimal when ensuring the reliability of the substation. This paper considers the dynamic change of money with time and environmental factors to build the substation three-dimensional model of life cycle cost.In order to study the importance of the model parameters on the total cost of the substation LCC, this paper makes sensitivity analysis of substation LCC by the traditional sensitivity analysis method and the comprehensive one. Combined with a practical example, the paper makes a ratio analysis of the substation life cycle cost, and preliminarily obtains the focus of substation LCC control. Then the comparison result shows that the comprehensive sensitivity analysis method is more scientific and reasonable. At last, we put forward the corresponding control strategies of substation LCC, which has certain guiding effect on optimizing the substation LCC in engineering application.In order to improve the usefulness and convenience of the LCC estimation, this paper uses the least squares support vector machine model to establish the prediction model of substation LCC. Through the genetic algorithm to find the global optimal solution of the LS-SVM model parameters and improve the precision of prediction. The research results show that the prediction accuracy and performance index of the LS-SVMprediction model with GA optimizing are superior to the traditional LS-SVM model and BP neural network model. It is helpful to achieve the rapid, efficient and objective prediction of substation LCC.There are some uncertain factors in substation life cycle cost which have effect on the LCC. However, we neglect the factors when modeling. In this paper, after establishing the deterministic model, we need make further study of the uncertain factors,namely LCC risk assessment. Firstly, this paper identifies the factors which influences the substation LCC risk and presents a risk assessment index system of substation life cycle cost. Applying matter-element model and extension analysis theory to quantify the qualitative indexes in order to assess the risk, we set up a risk assessment matter-element model of substation life cycle cost. Finally by an example to evaluate the risk grading of substation LCC, we find the key risk factors and put forward the measures to prevent and control the risk which has a guiding effect on the practical application.