基于模拟电荷法的绝缘子电场非接触式测量法

CHARGE SIMULATION METHOD BASED INSULATOR NON-TOUCHING ELECTRIC FIELD MAPPING METHOD

根据模拟电荷法的基本原理和绝缘子片的实际形状,采用环线形离散模拟电荷等效分布在绝缘子表面的束缚电荷,使模拟电荷产生的空间场的边界条件满足绝缘子的束缚电荷产生的空间场。测量绝缘子串附近一定距离范围内的几点(对于110 kV,可只测量3点)的电场强度,根据测量点的实际电场强度和采用模拟电荷法建立的等效模型,结合一定的搜索方法,可计算出绝缘子串的实际分布电压值。将绝缘子串的实际电压分布值与国家标准给定的电压分布值相比较,可判断出有无劣质绝缘子片及其位置,从而完成绝缘子的预防性检测,避免电力事故发生。与目前国内的电场测量法相比,这种方法采用程序计算来代替部分测量工作,可以带电检测,测量点少,操作方便,实现了一定距离的非接触式测量,避免测量装置直接与高压绝缘子接触,降低了操作的危险性。

According to the fundamental principle of the simulation charge method and the real figures of insulators, the appropriate ring simulated charges are used to substitute the chained charges on the surface of the insulators, under the condition that the field produced by the simulated charges should well satisfy the boundary conditions of the field produced by the chained charges on the surface of insulators. An instrument is used to measure the electric field produced by the voltage distribution on the high voltage insulators, and the electric field of several points in the area near to the insulators can be also measured. With the test data and the model found by the simulation charge method, the quantity of electric charge of the simulation charges can be worked out, and then the practical voltage distribution on the surface of the insulators can be calculated according to Maxwell's grid equations. Compared with the national standard of voltage distribution of insulators, it can be judged whether there is detective insulator among the insulators, also the number and position of the detective insulators. Hence, the electric power accident can be avoided and the electric power system can operate safely and steadily. Thanks to the use of the charge simulation method, part of the measurement can be replaced by the calculation software. One of the advantages of this method is that there is no need to break off the power during the period of measurement. Another is the number of the scale points is less than the current electric field mapping. Hence, the operation is much more convenient. In addition, the method of the non-touch electric field mapping can be achieved in certain range of distance to avoid the instrument touching the high voltage insulators directly, thus reducing the operation risk.