Research And Design Of The Online Monitoring And Early Warning System Of Transformer Hot Spot Temperature

With the rapid development of the national economy, a significant effect was sustained, rapid growth of power load; by contrast, the construction of the network is relative lag, which resulted in power transformer load rate in a higher position. With the increase of load rate, the transformer winding hot spot temperature will rise; the hot spot temperature rise will affect the transformer insulation capacity, and ultimately affect the life of the transformer. So we need the transformer has higher overload ability thatcould change and adjust the load according to the transformer hot spot temperature in real-time, whichcan not only avoid transformer fault occursdue to excessive damage, but also leave some spaceto dispatcher tocontrolload in safe and reliable within the scope. This paper focused on the traditional hot spot thermal circuit model, consideration of the environmental meteorological conditions,cooling ways, load rate of transformer internal temperature effects, establishedan improved model based on the average temperature, accurately calculated transformer winding temperature and hot spot temperature. Then developed a set of power transformer hot spot temperature on-line monitoring and early warning system, improve the safety and efficiency of transformer, which can adapt to the needs of social and economic development.First of all, this paper reviews the theory of transformer hot spot temperature and its calculation method, and analyzes the important significance and value; secondlyconstructs the thermal circuit model based on the average temperature and analyzesits applicability, compared with the national standard calculation method and transformer measured temperature rise, proves the validity of the model; then design a power transformer hot spot temperature on-line monitoring and early warning system based on the established hot spot temperature model; finally, the test result of the system show the validity and practicability of the designed system.