变电站绝缘子污秽在线监测技术

为实现电气设备在线监测的智能化和自动化,以单片机为核心开发了变电站绝缘子绝缘性能在线监测系统的远程终端,并且利用RS 485通信总线技术和后台计算机通信从而构成监测的整体系统。此系统远端可监测变电站的温度和相对湿度以及绝缘子的泄漏电流和脉冲电流,这些信息传送到中央计算机后通过模糊多级综合评判处理数据。模糊综合评判可以综合考虑多个因素对评判结果的影响,利用这一原理建立了绝缘子在线监测量同绝缘性能之间的模糊关系。模糊一级综合评判可给出绝缘子的在线绝缘性能,第二级综合评判即给出检修建议。通过此方法,监控人员可以远程在线监测变电站实时绝缘状况,同时可减少电网因绝缘问题引起的故障,在保证电网安全运行方面有参考价值。

Contamination of Substation Insulators On-line Monitoring Technology

It designs the RTU(Remote Terminal Unit) for on-line monitoring system to the insulator strings of substations based on single-chip,which is the core of the RTU and also included the signal adjust,A/D transform,and signal transform,for achieving the intelligent and automatic monitoring the electric equipment.The communication between RTU and centre computer is completed by RS 485 serial communication.The system is made of the RTU,RS 485 and the center computer.This monitoring system can monitor the temperature and relative humidity of the substation in real time and remote mode and it can also detect the leakage current and pulse current of insulator strings effectively.The information of insulator strings is transmitted to the center computer by RS 485 and processed by the software which is installed on the center computer and based on multilevel fuzzy comprehensive evaluation.For the multilevel fuzzy comprehensive evaluation can considered the effect between several factors and the assessed result comprehensively.It establishes the fuzzy relation between on-line monitoring data of insulators and the insulation of it using multilevel fuzzy comprehensive evaluation and mostly discusses the establishment of the fuzzy logical membership functions of the peak value of the leakage current,the virtual value of leakage current,the odd order harmonic of leakage current,the times of the pulse leakage current and the peak value of the pulse current and the foundation of fuzzy logical relation matrix.The system has the real-time early fuzzy warning function base on the first level fuzzy comprehensive evaluation, and according to the second level fuzzy comprehensive evaluation it makes suggestion to operator whether it should be maintained.Only this way,the dispatcher can long-distance on-line monitor the insulated status of the substation,and this system can decrease the fault of power system which is conducted by fault of insulation.It is very important to the power system for insuring the safe operation of the power system.