基于非接触式静电检测技术的电气设备接地实时检测系统的研究及应用

发布时间：2018-07-06 11:43

本文选题：非接触式 + 静电检测　；参考：《兰州理工大学》2017年硕士论文

【摘要】：在电力系统中,各电气设备的接地装置及变电站、发电厂内的接地网是否可靠、是否完整对电气设备的安全稳定运行起着重要的作用。电气设备的接地是否达标不仅影响电气设备的正常运行,而且影响运维与检修人员的人生安全。本文针对电气设备接地状况的监测手段比较单一,且费事费力这一现象,提出一种能够做到实时检测电气设备的接地状况的系统或装置。非接触式检测接地是否完好的方法有静电感应法和空气电离法两种,本文主要是利用非接触式静电感应检测这一方法,选取合适的传感器,由于静电传感器输出信号相对较弱,且受外界环境影响,导致其中含有大量噪声信号及其他干扰信号。所以信号采集系统对静电传感器的输出信号进行采集之前需要对其进行适当的处理来降低其中的干扰信号,通过检测探头与被检测设备的感应电场来检测带电体的表面电压降。通过振动电容式静电计测量设备表面静电的情况来监测电气设备接地状况,同时与传统的测试方法测读出的接地电阻进行比较,记录不同等级电气设备接地正常及接地不良时静电的积聚与泄放规律,从而推倒出准确判断设备是否接地不良的算法,完成接地电阻实时系统的硬件和软件系统的设计与研究。本文提出接地阻抗监测系统的稳定运行是由各种辅助电路来控制工作的,其中,包括模拟与数字电路以及单片机对其信号进行及时的处理和优化,使其达到想要的理想状态,并且符合电场测量所需要的精度值,方可直接用于监测和测量,使用静电感应技术采集接地阻抗后利用无线传输技术和现代电子技术,遵循自动化检测方向设计了一种非接触式接地电实时监测系统。系统设立多个观测站采集,每一个观测站均安装一台静电感应测试仪进行接地阻抗监测。本文对检测系统的电路组成,进行了一系列优化,使检测在最大程度上消除了各种可变因素对于电场测量带来的干扰,改善了在电场测量的相应精度。同时监控装置可以根据自身存储的数据来与静电检测仪发送的数据进行比较,从而得到装置接地是否可靠的信息。而远端多点测试的过程是由以上信息最终经由通信线路传到计算机监控室,计算机中心亦可将所有测量信号传输至各个线路,对其终端进行调节。工作人员可通过计算机的软件界面,实时操作控制,方可得到目前接地阻抗值,采集之后通过无线网络技术将数据发送至远方监控系统,完成变电站、发电厂电气设备接地状况的实时、远程监控,故障预警及定位。
[Abstract]:In the power system, the grounding device of each electrical equipment, the substation, the grounding grid in the power plant is reliable, and the integrity plays an important role in the safe and stable operation of the electrical equipment. Whether the grounding of electrical equipment meets the standard not only affects the normal operation of electrical equipment, but also affects the safety of operation and maintenance personnel. Aiming at the phenomenon that the monitoring method of grounding condition of electrical equipment is simple and laborious, a system or device that can detect the grounding condition of electrical equipment in real time is put forward in this paper. There are two kinds of non-contact detection methods: electrostatic induction method and air ionization method. This paper mainly uses non-contact electrostatic induction detection method to select the appropriate sensor, because the output signal of electrostatic sensor is relatively weak. And by the external environment, resulting in a large number of noise signals and other interference signals. So the signal acquisition system needs to deal with the output signal of electrostatic sensor properly to reduce the interference signal and detect the voltage drop of charged body by detecting the inductive electric field of the probe and the detected equipment before collecting the output signal of electrostatic sensor. The grounding condition of electrical equipment is monitored by vibrating capacitance electrometer to measure the static electricity on the surface of the equipment. At the same time, it is compared with the ground resistance read out by the traditional test method. This paper records the accumulation and discharge rule of static electricity in normal grounding and bad grounding of electrical equipment of different grades, thus pushing down the algorithm of judging whether the equipment is grounding bad or not, and accomplishing the design and research of hardware and software system of earthing resistance real time system. In this paper, it is proposed that the steady operation of the grounding impedance monitoring system is controlled by various auxiliary circuits, including analog and digital circuits and single chip computers, which can process and optimize their signals in time, so that they can reach the desired ideal state. It can be directly used for monitoring and measurement only if the accuracy of electric field measurement is satisfied. After collecting earthing impedance by electrostatic induction technology, wireless transmission technology and modern electronic technology can be used. A non-contact real-time monitoring system for grounding electricity is designed according to the direction of automatic detection. Several observation stations are set up in the system and each station is equipped with an electrostatic induction tester to monitor the grounding impedance. In this paper, a series of optimizations have been carried out on the circuit composition of the detection system, so that the interference caused by various variable factors to the electric field measurement is eliminated to the greatest extent, and the corresponding accuracy of the electric field measurement in the field is improved. At the same time, the monitoring device can be compared with the data sent by the electrostatic detector according to the data stored by itself, so as to obtain the reliable information about the grounding of the device. The process of remote multipoint testing is from the above information to the computer monitoring room through the communication line, and the computer center can transmit all the measurement signals to each line to adjust its terminal. Through the software interface of the computer and real-time operation control, the staff can get the current grounding impedance value. After collecting the data, they can send the data to the remote monitoring system through wireless network technology to complete the substation. Real-time, remote monitoring, fault warning and location of electrical equipment in power plant.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM862

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