Development of a PXI controller based data acquisition system for on line remote monitoring of leakage current on RTV coated insulators

The continuous operation of the transmission system is very important. For ensuring high levels of continuous operation it is not only important to select appropriate insulation withstand levels for various power apparatus, insulators etc., but it is also necessary to consider the pollution withstand levels for external insulation. Problems arise when the insulators, which are polluted and exposed to fog and light, rain, under ambient conditions, flashover at the operating voltage itself. The moistened pollution layer on the insulator surface conducts, thereby increasing the leakage current, in the field. To monitor the status of the insulator surface, leakage current is used as indicator worldwide. Researchers have developed online data acquisition systems for monitoring leakage current continuously. Long-term studies of the electrical phenomena on the polluted insulator surface necessarily demand the usage of an online data acquisition system (DAS) to continuously record the leakage current pulses caused by dry band or and corona discharge activity. A brief review of a few data acquisition systems are discussed below.