基于小分段的中压架空线接线模式分析

Medium-voltage Overhead Lines Connection Mode Analysis Based on Short Segment

线路分段数量与网架的紧密配合作为提高配电网可靠性手段之一,可以明显减少用户停电时间。文中在对可靠性与经济参数调研的基础上,将经济性和可靠性结合在一起,提出了一种高可靠性分段原则,继而提出了"小分段"的接线模式。研究表明,与国内习惯分段数(3～5段)相比,线路的分段数量大幅度增加,3～15km的10kV线路最优分段数增加为4～18段,有联络接线模式下系统平均停电持续时间指标从无分段的3.53～17.63h减小到分段后的0.67～2.19h,在保证社会经济效益的前提下显著提高了供电可靠性。最后,对影响最优分段数的参数进行了灵敏度分析,结果表明中压配电线路的最优分段数受到负荷开关单价、线路平均计划停运率、单位停电损失费用及负荷沿馈线分布情况的影响较大。

The close coordination between the number of line segments and the grid configuration, as one of the means of improving distribution network reliability, can significantly reduce the power outage time of users. Based on the research on reliability and economy parameters, a kind of high reliability segment rule is proposed with the grid economy and reliability considered together, and then a connection mode of short segments is presented. The result shows that, compared with domestic habitual segments （3 to 5）, the number of segments has a substantial increase, so that the optimal segment number of an 10 kV line of 3～15 km is increased to 4 to 18 and the system＇s average interruption duration index with a tie-connection decreases from 3.53～17.63 h with no segments to 0.67～2.19 h with optimal segments, greatly improving the power supply reliability with the economic benefit guaranteed. Finally, a sensitivity analysis for the segment related parameters is performed. The outcome shows that the optimal segment number of a medium voltage distribution line is greatly related to the price of a breaker/switch, the average planned outage rate, the energy loss cost and load distribution mode along the feeder.