Research on reliability-based feeder system planning methods

Feeder system is an important part of the distribution system, which is not only shouldering the mission of fulfilling social responsibility, but also related to economic benefit of power supply companies. In the traditional planning method of feeder system, power supply reliability is implicitly reached by “N-1” criterion, but it is not particularly effective in reducing costs and handling budgets. Therefore, this planning method does not meet distribution network differentiation and meticulous management requirements and it's difficult to protect the interests of power supply companies and consumers, unable to adapt to future development needs of distribution network. In this paper, based on the different requirements for power supply reliability in different regions, the key elements of feeder system (feeder capacity, zone, segmentation, protection, switching time, etc.) and their flexible configuration method were proposed. Based on coordination accident support capacity of different zone switching mode and transfer capability for feeder system, feeder system planning method that supports feeder layer outage, transformer outage and substation outage and the overall process of feeder system reliability design were put forward, to ensure planning scheme achieve satisfactory electrical performance, accident control, optimal power supply reliability and economy. Finally, distribution network optimal planning in high reliability demonstration area of a city was selected as an actual case and satisfied planning scheme was obtained, to verify the effectiveness of the proposed planning methods.