The Study Of Distribution Network Maintenance Optimization Based On Risk Assessment

Power distribution network is the last part of power system, connected with the users directly. The failure of distribution grid will directly affect the continuous stability of electricity, and directly cause huge losses of society. Therefore, maintaining sustained and stable operation of the distribution network is an important task of the power grid. Due to distribution network’s various nodes, wide distribution and complex network structure, the maintenance of the distribution network is a complex engineering which needs coordination and balance from various aspects. In order to ensure the reliability of power supply, the maintenance of distribution network should be economic and efficient each time. Reasonable selective maintenance plan is the guarantee of repair work, and the premise of establishing selective planning is to have sufficient risk assessment and reliable equivalent calculation of the distribution network.Therefore, from the present condition of power distribution network, this paper first introduces the distribution network risk assessment model, which adopts a series of logical steps, giving the relevant risk indicators, mastering the probability and severity of the accident quantitatively, thus reflect the effects of the accident to the entire power system fully. Furthermore, this paper analyses the grid equivalent method of transmission system for distribution network reliability assessment, which considers the system’s constraints of safety and stability. In order to obtain designate node’s maximum load capacity under different system states, this article adopts Monte Carlo simulation method to sample system’s state, and combines with the evaluation model to present the distribution of node’s maximum load capacity. Based on the risk assessment model of distribution network, this paper puts forward selective maintenance plan of distribution network, which optimizes the equipment maintenance implementation time. First of all is risk identification, by decoupling components’ failure rate to realize the analysis of individual risk factors; and then is the risk assessment:by establishing decision tree to obtain different schemes under different state transitions, afterwards from the economic perspective, to determine the optimal maintenance plan to implement the risk mitigation.Finally, based on the PG&E69 and RBTS transmission systems, this paper makes equivalent process to the transmission power grid, and proves the effectiveness of selective maintenance plan based on risk management, which has a good application prospect.