Study and application of portable leakage current monitoring system

Measuring the leakage current of insulator surface is an implementable and effective method to evaluate the insulator contamination. This paper proposed a portable leakage current monitoring system for site outer insulation studies. Difference mode has been applied in this system for common mode signal reduction. The synchronous sampling rate can reach 20kS/s, which can record full information in the leakage current data. Resistor sensor has been applied in this system, which has a good electromagnetic interference performance. This system has a wide measuring range from 0.1mA to SA, relative error can be controlled within 2%. Applied voltage values on the insulator can also been measured through this system when correlating with a voltage divider. LabVIEW has been applied for software platform building of the system, which is easy to operate, rich in functions and extendible. Features of this system are light weight, small volume, economic and convenient to implement. This system can fit varies site applications for research institutes.