复合绝缘子接地电流的测量及其特性研究

Study on Measurement of Grounding Current and Its Characteristics for Composite Insulator

目前检测复合绝缘子污秽状况的主要方法是泄漏电流法。这种方法需要在绝缘子上加装电流传感器,加大了测量难度和危险性。文章提出了通过测量绝缘子接地电流来检测复合绝缘子表面污秽程度的方法.对复合绝缘子的接地电流特性进行了研究,分别建立了复合绝缘子接地电流、体泄漏电流和表面泄漏电流的测试回路,对洁净和污秽条件下复合绝缘子上述3种电流进行了测量和比较分析。试验结果表明:污秽奈件下复合绝缘子接地电流及表面泄漏电流的幅值比洁净条件下的都有明显增大,而且增大的幅度基本相同,而波形上谐波成分大大减小,但体泄漏电流基本没有变化。因此,通过测量复合绝缘子接地线上的接地电流可以用于检测出复合绝缘子的污秽程度。

The major method now for detecting pollution condition of composite insulator is to detect leakage current. This method needs to install the current transducer on insuhtor, which increases the measurement difficulty and danger. The paper presented the method to detect the pollution degree of composite hasulator surface by measuring its grounding current. To test and verify the practicability of detecting the pollution degree of composite insulator surface, it is necessary to study the characteristics of composite insulator grounding current. In this paper, three kinds of measurement circuit were set up to measure the grounding current, the body leakage current and the surface leakage current separately of the composite insulator, and under clean and pollution condition the three kinds of current of the composite insulator that had mentioned before were measured and analyzed respectively by comparing the three kinds of current. The results show that the grounding current and the surface leakage current amplitude of pollution composite insulator inereased obviously compared with the clean condition, and they almost have the same increase, as well their harmonic component decreases greatly with the same rate. However, body leakage current almost has no change compared with the clean one. The pollution degree of composite insulator surface can be detected by measuring grounding current on the insulator grounding line.