北京10kV配网合环试验与分析

为了保证重要用户的不间断供电,提高城市配电网的供电可靠性,北京电网10kV配电出线带电倒负荷的操作频繁。因合环开关两侧母线或线路存在电压差等原因,可能使合环操作中产生过大环流,引起过流保护或速断保护误动。合环以沙窝站为例,介绍了试验条件、合环试验接线、方法、步骤和安全措施。通过研究合环暂态和稳态过程,提出了合理的合环仿真模型和计算方法,计算了合环稳态电流和合环瞬时最大冲击电流。根据对试验数据、录波波形与仿真计算结果的分析对比,探讨了影响安全合环的主要特征量,给出了安全合环的主要调整措施,得出的结论对电网实际运行具有指导意义。

Loop closing examination and analysis on Beijing 10 kV distribution network

The online operation is quite frequent in Beijing 10 kV distribution network in order to ensure the continuous power supply to important consumers and to increase the network reliability. Mal-protection operation or over-current circumstance might occur because of tremendous loop current during the loop closing if there is a voltage difference between the terminals of the switch. The loop closing examination strategies as well as safety precaution methods were introduced and the loop closing equivalent model was established with an example of Shawo Substation. Making a study of transient and steady process in loop closing, the steady-state loop current and the transient rush current were also calculated. Comparing the recorded diagram with the power flow calculation results, key factors affecting the loop closing safety were discussed. Main adjustment measures for loop closing safety are suggested to limit the loop current, which have instruction significance to the network operation.