摘 要

近年来，随着智能电网的发展，变电站中要求使用越来越多的智能二次设备。二次设备诸如电子式电流互感器，汇控柜等一旦遭受电磁干扰，将严重影响变电站的可靠运行。开关操作是变电站中产生操作过电压及其暂态过程的主要原因。因此，进行断路器开关操作实验是评判且保证GIS变电站安全可靠运行的重要依据。

本文从开关操作的电磁干扰源，干扰对象和干扰产生的影响三个方面总结了国内外开关操作的电磁干扰的研究现状。暂态过电压过电流引起的电磁辐射的研究仍处于初期阶段。因此，本文的主要工作是研究壳体暂态过程的产生机理，建立壳体暂态过程的电磁干扰模型，并解决由壳体产生的空间辐射电磁场的大小。GIS壳体在开关操作条件下的瞬时循环。

首先，本文研究了GIS壳中的电磁干扰源产生的机理。当操作该开关时，在GIS外壳上会发生外壳电位上升现象（TEV）。因为GIS外壳具有电气连通性，所以TEV会导致外壳和地面或外壳与外壳之间的环路产生电流，这就是外壳的暂态过电流。可以看出，建立TEV模型以准确计算TEV是分析壳的暂态过程的前提。 TEV的计算包括建立GIS套管模型，开关操作激励源的确定，GIS内部和外部的电磁波的传播路径以及变电站二次设备受到的干扰测量。

为了得到暂态过程产生电磁波的传播路径，采用XFDTD有限元仿真软件对1：1的110KVGIS套管模型进行仿真。在以上研究的基础上，建立了精确求解TEV的计算模型。

获得壳体暂态过程的数学表达式是建立GIS壳体辐射模型及麦克斯韦方程的基础。为此，对TEV波形数学方程的拟合进行了研究，以便在TEV数学表达式拟合的基础上通过欧姆定律获得仿真模型以及有效的电磁场计算方法的数学表达。在对TEV波形数据进行统计分析的过程中，分析了TEV波形的周期性，重复性，幅度变化特性，并结合阻尼正弦电流波形与正弦交流电拟合得到了典型的TEV波形。获得TEV激励源波形的表达式。在此基础上，分析了GIS壳体的阻抗特性，建立了GIS壳体暂态过程的计算模型，得到了GIS壳体暂态电磁场在不同时间，不同地点对应的强度大小，分析了壳体暂态电流的特性和影响。以及影响壳内暂态过程的主要因素。

为了获得壳体外的暂态电磁辐射分布，本文根据天线模型建立了开关操作时GIS壳体辐射模型及其开口泄漏模型。通过对辐射模型的仿真，得到了开关操作条件下GIS内部与外部空间中暂态辐射电场和磁场的强度大小及其时域传播路径。同时，为验证辐射模型的正确性，在110kV GIS平台上进行了开关操作条件下GIS外部空间的辐射电磁干扰测试，并在不同距离之间的电场强度进行了测试。测量了TEV和GIS外壳。测试结果不仅验证了模型的正确性，而且还揭示了开关操作过程中产生的辐射干扰超过了GIS变电站所允许的电磁兼容水平。因此，应充分注意由开关操作引起的辐射电磁干扰。

最后，分析了开关操作的辐射电磁场对智能元件的干扰，并提出了相应的抑制措施。

关键词：开关操作；GIS套管模型；电磁暂态；智能电子二次设备；开口泄漏辐射模型

Abstract

Recently, with the development of smart grids, more and more secondary equipment are required in substations. Once the secondary equipment such as the electronic current transformer or HSBC ark suffers from electromagnetic interference, it will seriously threaten the safe operation of the substation. Circuit breaker operation is the most typical and most important source of Operating overvoltage and its transient process in substations. Therefore, the electromagnetic interference of Circuit breaker operation is of great significance to ensure the security, reliability of GIS substations.

This paper concludes the research status of electromagnetic interference of circuit breaker operation at home and abroad from three aspects of electromagnetic interference source, interference object and interference results of circuit breaker operation. The research of electromagnetic radiation caused by transient overvoltage and overcurrent is still in its infancy. Therefore, this paper is about to find out the generation mechanism of the shell transient process, establish the electromagnetic interference model of the shell transient process, and solve the size of the space radiated electromagnetic field generated by the shell. The instantaneous cycle of the GIS shell under the switching operation conditions.

First, this paper does some research on the mechanism of electromagnetic interference sources in the GIS shell. When the circuit breaker operation begins, a rise in shell potential (TEV) occurs on the GIS shell. Because the GIS enclosure has electrical connectivity, TEV will cause a current in the loop between the enclosure and the ground or between the enclosure and the enclosure. This is the transient overcurrent of the enclosure. It can be seen that establishing a TEV model to accurately calculate TEV is a prerequisite for analyzing the transient process of the shell. The calculation of TEV includes the establishment of the GIS bushing model, the determination of the excitation source of the switching operation, the propagation path of the electromagnetic waves inside and outside the GIS, and the measurement of interference received by the secondary equipment in the substation.

In order to obtain the propagation path of electromagnetic waves generated during the transient process, XFDTD finite element simulation software was used to simulate the 1: 1 110KVGIS casing model. Based on the the research this paper does, a calculation model for accurately solving the the propagation path and intensity of electromagnetic field is established.

Obtaining the mathematical expression of the shell transient process is the basis for establishing the GIS shell radiation model and Maxwell's equations. To this end, the fitting of the mathematical equations of the TEV waveform is studied, in order to get the simulation model and the the simulation results of the effective electromagnetic field calculation method by maxwell's law based on the theory of electromagnetic field transmission. During the statistical analysis of the TEV waveform data, the periodicity, repeatability and amplitude change characteristics of the TEV waveform were analyzed, and the typical TEV waveform was obtained by combining the damped sinusoidal current waveform with the sinusoidal alternating current. Get the expression of the TEV excitation source waveform. On this basis, the impedance characteristics of the GIS shell are analyzed, and the calculation model of the transient process of the GIS shell is established. The strength of the transient electromagnetic field of the GIS shell at different times and different locations is obtained. The characteristics and influence of the on-state current. And the main factors affecting the transient process in the shell.

In order to obtain the transient electromagnetic radiation distribution outside the shell, this paper uses the antenna theory to establish the leakage model of the GIS shell opening leakage of the electric dipole. from the simulation results of the radiation model, the distribution of the transient radiated electric field and magnetic field in the external space of the GIS under the circuit breaker operation is obtained. meanwhile, to verify the correctness of the radiation model, on the 110kV GIS platform, the radiated electromagnetic interference test of the internal and external space of the GIS under the circuit breaker operation was conducted, and the electric field strength between different distances was tested. The TEV and GIS enclosures were measured. The test results not just simply verified the correctness of the model, it also shows that the radiated interference generated during the circuit breaker operation exceeded the electromagnetic compatibility level permitted by the GIS substation. Therefore, full attention should be paid to radiated electromagnetic interference caused by switching operations.

Finally, the interference of the radiated electromagnetic field of the switch operation on the smart components is analyzed, and corresponding suppression measures are proposed.

Keywords: switch operation; GIS bushing model; electromagnetic transient; intelligent electronic secondary equipment; opening leakage radiation model

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