Research On The Life Cycle Management Theory And Method In Distribution System Planning

The distribution network is an important part in the power system. Comparing with developed countries, the distribution network in China is backward and the investment is inadequate. With the sustained and rapid development of China's economy, there is much room for development of distribution network in the future. As the distribution system has the characteristics of systematicness and long-term, the costs of operation and maintenance stages have a large proportion in the life cycle cost. It is important for the network planning and operation staff that all costs of distribution network planning and the operational stage were analyse using the life cycle management theory in the ditribution planning and design. By the method not only the economy and the reliability of the planning scheme can be optimized,but also the life cycle cost minimization and the economic and social benefits maximization can be achieved. So the the ditribution system planning based on the life cycle cost is important to build safe, reliable and economic distribution network. In this paper, the theory of life cycle management is applied in all aspects of distribution network planning, the main research results are as follows:1. The whole process of distribution network planning, construction and the operation management was analysised deeply. The life cycle of distribution system planning was divided into different stages and the calculation methods and the economic evaluation methods based on the LCC were established. The theoretical foundation of the life cycle cost management theory applycation in distribution network planning was built.2. The new model of substation locating and sizing planning based on the life cycle cost of equipment was presented. The initial investment, operation and maintenance cost, fault cost and disposal cost of the high voltage transmission lines, the lower voltage distribution networks and the substation equipment were considered. The certain reliability and the optimal economy of the planning scheme were considered in the model. The ArcGIS spatial analysis function was used to overcome the constraint of geographical factors of planning substation, and the planning efficiency was improved. The improved algorithm based on the k-mean clustering algorithm and multi-swarms stochastic particle swarm optimization algorithm was presented. The new algorithm's global searching capability was improved tremendously.3. The new model of the distribution network planning and the configuration of switches based on the life cycle cost of equipment was presented. The initial investment, operation and maintenance cost, fault cost and disposal cost of planning scheme were considered in the new model. The planning scheme not only meet the optimal economic, but also was reliable. The function of outage cost was built, and the new function reflected the comprehensive effect of the frequency, duration and quantity of outage to the outage cost. This method was more scientific and accurate to calculate the outage cost. The improved algorithm based on the combined mean clustering algorithm and random particle swarm algorithm was represented. The new algorithm's global searching capability was improved observably.4. A mathematical model was proposed with the objective function of maximum net benefit in present value, and the model showed the benefit of power loss reduction vividly. The clustering and crowding niche genetic algorithm was used to the reactive power planning of distribution network, and it enhanced the ability of global optimization and the stability of results by adjusting the cluster distance.5. The life cycle security, efficiency and cost management method of distribution network equipment with distribution feeder as the basic unit was presented. The evaluation model of distribution network planning scheme based on the annual security efficiency and cost index was built. According to the distribution system characteristics the safety indexs and the life cycle cost calculation method of the model were defined. The model not only meet the optimal LCC, but also cansidered the security effectiveness value of the planning program. So the shortcoming without considering the utilization rate of the model based on only the LCC value was overcome. The calculation programming of distribution equipment asset life cycle information management and indexs evaluation was developed, and the method provided a basis for making decision of equipment selection and distribution network planning evaluation, improving the management efficiency and the accuracy of decision making.