Line Monitoring System Of Power Transformer Core Ground Current Study

The power transformer is one of the most important electrical equipments in the power system, whether it can run safely and stably or not will affect the reliability of the power supply and the normal operation of the system. So a fixed-time or real-time online monitoring of the running state of the transformer is very important.In the working process of the transformer, multi-point grounding of the transformer core could lead to too big grounding current which can burning the core. In order to prevent burning fault of transformer core, an online monitoring system based on GSM wireless communication technique of the current in the grounding loop of the transformer core is introduced. In this paper, the automatic switch range circuit can process the signal which comes from the current transformer to ensure the accuracy of the data. When the chip MAX197 finish the convert of analog to digital, the signal goes in to the CPU(Central Processing Uint). CPU can control the LED module to display the current. And users can operate the keyboard according to their needs, for example, setting the time interval of sending current value from CPU to cell phones, the warning value of the current and the short message center number.This system could real-time monitor the grounding current of the transformer core and store the historical data. When the grounding current exceeds the national standard, the system will generate an alert signal and control the resister automatically, which limited the current in the demand of operation standard.