Study On Heat Flow Model And Hotspot Of Transformer Heat Loss

Transformer is commonly used equipment in power system, its importance is self-evident. The safe operation of transformer directly affects the safety of the electric power transmission and distribution. In the long run, due to various losses, the internal of oil-immersed transformer produce a large amount of heat, and the heat produced in the transformer internal will has a serious impact on the service life of the transformer internal components. At the present, the faults caused by overtop temperature of transformer have been more and more. To make a modeling analysis of 35 kV oil-immersed transformer, and then calculate the loss and heat of each part produced in 35 kV oil-immersed transformer when it is fully loaded and running stably by electromagnetic field simulation software--- Maxwell. In the next, change the loss data into heat load, and input it to ANSYS CFX in order to make a temperature analysis of the 35 kV oil-immersed transformer. After all of the steps, we can get the temperature rise distribution of oil-immersed transformer. Through the temperature field research to the 35 kV oil-immersed transformer, we can provide a kind of simulation calculation method of the transformer temperature rise to transformer designers.We may also provide certain reference to someone who makes transformer temperature testing.This article main research content is as follows:(1)According to the three heat transfer principle, including heat conduction, convection heat transfer and heat loss through radiation, plus the calculation model of solid area, solid-liquid interface, the fluid flow field,at the same time, we use the ANSYS software to establish finite element analysis model of 35 kv oil-immersed transformer. In the paper, we have established models mainly aimed at the core, winding, and tank.(2)Using the electromagnetic simulation software---Maxwell to make a electromagnetic simulation for 35 kv oil-immersed transformer; Combined with the thermodynamics theory knowledge, we get the core loss, high voltage winding loss, low voltage winding loss, and eddy current loss. And then, we calculated the calorific value and heat density of core, high voltage winding, low voltage winding and the structure parts according to the loss.(3) to input calculated the heat load in the ANSYS CFX, and to early to set up the simulation parameter of the finite element analysis model of 35 kV oil-immersed transformer, and then on the basic of considering the transformer oil flow, make a simulation analysis of the temperature field of the 35 kV oil-immersed transformer when it is running by the ANSYS CFX. Through those steps, we can get the temperature distribution map of the transformer.