基于10kV配电网PT频繁故障的仿真与改进措施研究  

Simulation analysis and improved measures for preventing potential transformer fault in 10 kV distribution networks

作　　者：李雷[1] 罗容波[1] 王岩[1] 傅正财[2] 

机构地区：[1]广东电网公司佛山供电局,广东佛山528000 [2]上海交通大学电气工程系电力传输与功率变换控制教育部重点实验室,上海200240

出　　处：《电力系统保护与控制》2014年第14期132-137,共6页Power System Protection and Control

摘　　要：为了准确分析10kV母线并列电压互感器(PT)熔断器频繁熔断的原因,以某地区110kV变电站为例,首先对其PT频繁故障原因进行分析,然后根据该站的实际参数,利用ATP/EMTP仿真软件进行了模型仿真研究。分析表明,电网线路对地电容放电产生的暂态冲击电流是导致该变电站熔断器发热,从而引起母线PT频繁故障的直接原因,同时发现三组并列PT励磁特性不同引起暂态冲击电流分布不均亦是熔断器熔断的重要原因。基于此,提出在PT中性点加装消谐器或改用4PT接线方式等改进措施。仿真结果表明,上述措施对限制单个PT的暂态冲击电流具有显著效果。但当母线有多PT并联时,需同时考虑各个PT,以杜绝任何PT的熔断器因过流被熔断。To analyze the reason why the 10 kV potential transformer （PT） frequently fused, taking a 110 kV transformer substation for example, it summarizes the theories firstly. Then, simulation of a power system model is performed according to the actual parameters of this substation using the ATP / EMTP simulation software. It concludes that the transient inrush current caused by ground capacitor discharge is a direct reason for frequent fault of the 10 kV PT. Also, the unbalanced distribution of the inrush current caused by different excitation characteristics of PTs, is an important reason for its fuse. Based on this case, it proposes several improvements such as installing resonance eliminator in the neutral points of PT, or switching to 4PT wiring. The simulation shows great improvement on limiting the transient inrush current of a single PT. But when several PTs are paralleled, the condition of each PT should be accounted in order to eliminate any possibility of PT being fused by overcurrent.

关 键 词：配电网 电压互感器 熔断器 故障仿真 暂态电流 

分 类 号：TM451[电气工程—电器]