智能变电站线路保护系统检修周期的优化方法研究

Research on Optimization Method of Maintenance Period for Transmission Line Protection System in Smart Substation

为了优化智能变电站线路保护系统检修周期,以降低线路保护系统的运维检修成本,利用威布尔分布函数和表征检修对设备故障率影响的改善因子,建立了计及设备老化与不完全检修的设备故障率模型。利用可靠性框图法,建立了智能变电站线路保护系统的故障率模型。根据线路保护系统的故障率在稳定运行期与损耗期具有的不同变化规律,在两个阶段采用不同的检修周期。考虑了直采直跳、直采网跳、网采网跳3种采样跳闸模式、单重和双重化线路保护配置以及不同检修等级的维修成本等因素,构造了智能变电站线路保护系统的年均运行成本模型,并给出了年均运行成本最小时两阶段的最佳检修周期的求解方法。针对各采样跳闸方式下单套与双重化配置的保护系统进行仿真实验,获得相应的平均无故障工作时间、可靠运行时间、年均运行成本等指标,验证了所提方法的有效性。

In order to optimize the maintenance periods of transmission line protection system in smart substation,and reduce its operation and maintenance costs,an equipment failure rate model is proposed,considering equipment aging and incomplete maintenance and using Weibull distribution function and the improvement factor of maintenance for the failure rate of equipment.With the method of reliability block diagram,a failure rate model of the protection system is established.According to the different laws of the failure rate for the protection system in stable-operation and deterioration stages,different maintenance periods are adopted in the two stages respectively.An annual average operating cost models of protection system are established for the single and dual transmission line protection configurations with three sampling trip modes,i.e.direct sampling and direct tripping,direct sampling and net tripping,net sampling and net tripping,and the maintenance costs of different maintenance grades.The solving method of best maintenance periods of the two stages under the lowest annual average operating cost is studied.Simulations of the two protection configurations under each sampling trip mode are performed to obtain the mean time between failures,reliable operation time and annual operation cost,validating effectiveness of the proposed method.