126 kV GIS盆式绝缘子介质损耗测试方法及应用

Measurement Method of Dielectric Loss of 126 kV GIS Basin-type Insulator and Its Application

针对绝缘子老化测试或变电站在役GIS绝缘子绝缘状态评价的问题,研究一种GIS绝缘子介质损耗测试方法颇为重要。文中开发了一种基于电流比较仪式电桥的介质损耗测试装置,对全新和服役五年的绝缘子进行了电容和介质损耗测试,并对同类新品和运行抽检绝缘子进行了性能测试和试验验证。结果表明:电流比较仪式电桥具有较高的精度,该测试系统的介质损耗测量误差在2%以内,可以保证测试结果的有效性;全新绝缘子具有良好的电气绝缘性能,电容和介质损耗的测试结果无变化,多年服役绝缘子介质损耗值与全新绝缘子相比变化明显,可用来作为评价绝缘子老化状态的一个特征参数。

A dielectric loss testing device based on current comparator bridge was developed for testing the aging of insulator and evaluating insulation status of in-service GIS insulator. The dielectric loss standard device was used to verify the developed device. The results show that the measurement error of the developed device is within 2%, which can ensure the effectiveness of the test results. The new insulators and the insulators after five-year service were sampled to test their capacitance and dielectric loss. At the voltage of 20 kV, the new insulators showed good electrical insulation property, and their capacitance and dielectric loss did not change during test;however, the insulators after five-year service showed obvious change in the testing data of capacitance and dielectric loss, especially in the data of dielectric loss. Therefore, the dielectric loss can be taken as a characteristic parameter to evaluate aging status of the basin-type insulators.