Development And Application Of Monitoring Device Of Transformer Core Current

So far the intelligent power grid is being developed at home, and the on-line monitoring system for transformer core is a very important part, the working condition of iron core can be judged accurately through on-line monitoring of transform core,so that to maintenance in time before failure, whichcan not only improve the reliability of power supply effectively, but also reduce the operation cost of power system, so it has very vital significance toensure the safe operation of power transformer. In this paper, an on-line monitoring of transformer core system is developed, to solve the problem of theprecision and accuracy of the data cannot be guaranteed though previous methods and faults which cannot be found in time on regular visit.In this paper the earth current theory is analyzed, the system hardware circuit and the design of the system structure are designed and tested. The development of on-line monitoring of transformer core device has following functions: core earth current real-time monitoring, core earth current limit alarm,historical data storage and query functions.This device is by using high precision wear heart type current transformer suit in the transformer core grounding line method to get core/clamp grounding current signal, the current signal obtained by this method can reflect the change of core earth current, and because of no electrical connection withtransformer, there is no impact on the operation of the transformer.