On-line monitoring system of insulator leakage current based on ARM

A ceramic insulator has an excellent anti-pollution performance, but sometimes flashover occurs on it and then the outage of power network follows. This paper analyzes the formation mechanism of flashover and the result is that the RMS of leakage current(LC) and discharge pulses reflect the contamination severity approximately. This shows that to a large extent the flashover accident can be avoided by means of monitoring the leakage current value and the discharge pulses. Existing monitoring device for contaminated insulators inspects either leakage currents or discharge pulses, also, it is difficult to meet the requirements of the client for low-power consumption, low cost and high reliability. In this paper, a novel low-power and low-cost online monitoring system is presented, which is based on ARM Cortex-M and Zigbee wireless network. In addition, the monitoring system not only acquires the leakage current and discharge pulses of insulator strings, but also measures the environmental temperature and humidity and then comprehensively analyzes the severity of insulator pollution. After that the results will be displayed on the LCD or sent to the control center through the Zigbee network. Tests show that the monitoring system has good accuracy and good practical performance.