Multi-stage Equipment Asset Joint Optimization Configuration Method For Distribution Network Considering Life Cycle Cost

With the development of the economy,residents demand for power reliability has gradually increased.In recent years,our country has continuously increased the investment in the distribution network in order to improve the reliability of the distribution network in a variety of ways.However,the various departments of the power grid lack detailed connection and blindly invest in reliability improvement from multiple perspectives such as planning,operation,and maintenance,which can not achieve joint configuration,and leading to the waste of assets.Thus,this thesis has carried out the following work in the joint optimization configuration of the reliability improvement measures of the distribution network:Firstly,a cost model of reliability improvement measures for the distribution network based on the life cycle theory is established.The cost composition of the distribution network equipment is analyzed.Considering the actual distribution network planning and operating cost accounting methods,refined distribution network transformation cost models are established for the three methods commonly used in the process of improving the reliability of the distribution network,namely grid structure transformation,distribution automation transformation and live operation.Secondly,this thesis uses the failure consequence analysis method to establish the reliability evaluation model of the optimal configuration of the distribution network reliability improvement measures.The distributed generation(DG)island operation capability is quantified as a probability model,while taking into account the grid topology,the calculation models for component fault repair time and planned power outage time are established,and a fault action time calculation model is established based on the influence of distribution automation and live work.Thirdly,a joint optimization configuration method for multi-stage equipment assets of the distribution network is presented in this paper,with the lowest life-cycle cost as the goal,and the stage reliability requirements as the constraint,which comprehensively optimizes the configuration plan of grid structure transformation,distribution automation transformation and live work.At the same time,a dynamic optimization model solution method based on grid search is proposed.Finally,an example of a regional distribution network is applied to simulate and analyze the optimal configuration model to verify the feasibility of the model.Then,the differences among multi-stage joint optimization,single-stage joint optimization,and non-joint optimization strategies are compared,and the effectiveness of the multi-stage joint optimization configuration model is proved.Meanwhile,the influence of DG access on the configuration of the reliability improvement measures of the distribution network is measured.The simulation results show that the joint optimization configuration method of multi-stage equipment assets in the distribution network can effectively avoid the problems of excessive investment and blind investment in the distribution network.