Electric Field And Temperature Field Calculation And Analysis Of Papper Oiled Bushing

Paper Oiled condenser bushing is an important part of the substation, mainly working with a transformer and a reactor, carrying conductive current and insulation to the ground. Running conditions of a bushing is harsh, effected by the voltage and current. Dielectric heating and conductive medium heating caused by eddy current make the dissipation of heat difficult, resulting in insulation aging and even heat breakdown. The power equipment failure rate is quite high which has a serious influence on power system reliable operation.Based on 550 kV bushing, the finite element method is used to calculate electric field distribution. The dielectric loss is got. The finite element model of flange, condector and the out line device are established and the magnetic flux density distribution is calculated. The joule heat is got. The temperature field distribution of 550 kV bushing is calculated and the regular is got. The temperature simulation value of each point is compared to the measured temperature value to check whether the temperature rise is reasonable. The results show electric field distribution is uniform inside the bushing, with a maximum value of 4.54kV/mm. The dielectric loss value is totally 54.1527 W, mainly produced in the sleeve core. The joule heat loss value is totally 1149.7W and mainly concentrates on the guide bar. The total heat is 1203.89 W, including 4.50% dielectric loss. The highest temperature appears on the conductor in the transformer oil, with a value of 87.27℃. It is found that calculated temperature value is identical with the experimental temperature illustrating that the method is valid for calculating the bushing temperature distribution.The electric field distribution is calculated in 800 kV bushing with finite analysis. It is needed to establish the finite element model to get the temperature distribution. The temperature distribution is calculated under 2500 A. The temperature law is analyzed and the temperature near the metal is tested. Calculation results show that in the bushing, the temperature is high at the bottom and the temperature is low in the top. The highest temperature appears in the conductive rod, with a value of 86.48℃. The calculation results is useful for the optimization design of bushing and provide the basis for the theory and practice.