Research of the Temperature Field Distribution Based on FVM for Oil-Immersed Transformer

2014 ◽  
Vol 1079-1080 ◽  
pp. 510-514
Author(s):  
Yong Qiang Wang ◽  
Jie He ◽  
Lun Ma ◽  
Liu Wang ◽  
Ying Ying Sun ◽  
...  
Keyword(s):  
Temperature Field ◽  
High Temperature ◽  
Temperature Distribution ◽  
Field Distribution ◽  
Hot Spot ◽  
Load Capacity ◽  
Normal Operation ◽  
Internal Temperature ◽  
Temperature Field Distribution ◽  
Spot Temperature

Thehottest spot temperature (HST) of windings of oil-immersed transformer is animportant factor that affects load capacity and operation life of transformer,and is closely related to the transformer load, top oil and environmenttemperature. HST, when operating at high temperature and overload, may lead totransformer failure which will affect the normal operation of the power system.In order to calculate the transformer hot spot temperature accurately, we takea 33MVA-500KV transformer as an example, and establish a three dimensionalmodel, get its internal temperature distribution based on Fluent simulationsoftware. At last, we comparative and analysis the accuracy of FVM calculation andIEEE guidelines recommend model combined with online monitored values. Theresults show that the FVM method with higher accuracy relative to the IEEEguidelines model, proved that using the FVM can accurately calculate the HST ofoil-immersed transformer.

scholarly journals Three-Dimensional Electro-Thermal Analysis of a New Type Current Transformer Design for Power Distribution Networks

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1792
Author(s):  
Bingbing Dong ◽  
Yu Gu ◽  
Changsheng Gao ◽  
Zhu Zhang ◽  
Tao Wen ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Temperature Field ◽  
Temperature Gradient ◽  
Field Distribution ◽  
Distribution Network ◽  
Current Transformer ◽  
Internal Temperature ◽  
Temperature Field Distribution ◽  
Type Design ◽  
New Type

In recent years, the new type design of current transformer with bushing structure has been widely used in the distribution network system due to its advantages of miniaturization, high mechanical strength, maintenance-free, safety and environmental protection. The internal temperature field distribution is an important characteristic parameter to characterize the thermal insulation and aging performance of the transformer, and the internal temperature field distribution is mainly derived from the joule heat generated by the primary side guide rod after flowing through the current. Since the electric environment is a transient field and the thermal environment changes slowly with time as a steady field under the actual conditions, it is more complex and necessary to study the electrothermal coupling field of current transformer (CT). In this paper, a 3D simulation model of a new type design of current transformer for distribution network based on electric-thermal coupling is established by using finite element method (FEM) software. Considering that the actual thermal conduction process of CT is mainly by conduction, convection and radiation, three different kinds of boundary conditions such as solid heat transfer boundary condition, heat convection boundary condition and surface radiation boundary condition are applied to the CT. Through the model created above, the temperature rise process and the distribution characteristics of temperature gradient of the inner conductor under different current, different ambient temperatures and different core diameters conditions are studied. Meanwhile, the hottest temperature and the maximum temperature gradient difference are calculated. According to this, the position of weak insulation of the transformer is determined. The research results can provide a reference for the factory production of new type design of current transformer.

Influence upon temperature field distribution with straight grooves parameters of clutch friction disk

2020 ◽  
Vol 234 (9) ◽  
pp. 2263-2278
Author(s):  
Jie Li ◽  
Yanxiong Zhang ◽  
Xiaoyan Wang ◽  
Jialing Gu ◽  
Cheng Chen ◽  
...  
Keyword(s):  
Temperature Field ◽  
High Temperature ◽  
Field Distribution ◽  
Friction Pair ◽  
Structural Parameters ◽  
Temperature Inhomogeneity ◽  
Temperature Field Distribution ◽  
Thermoelastic Instability ◽  
Temperature Range ◽  
Average Temperature

The instability of the temperature field distribution in clutch friction pair tends to increase exponentially with time when the relative velocity is greater than a certain critical value, which indicates the system enters a state of thermoelastic instability. During high-speed frictional sliding at a high temperature and high pressure, thermoelastic instability will generate local high temperature on friction pair and then cause high-frequency vibration, warping, fatigue fracture, and so on. With the aim of studying the problems arising from local hot spots and the mechanism behind the characteristics of temperature field in friction pair, a thermoelastic finite element analysis model was established for friction pair of heavy-duty vehicle clutch in this paper. The characteristics of thermoelastic stress and temperature distribution under different conditions were obtained by simulation analysis where different values were applied to groove distribution parameters such as number, angle, depth, and width. Experiments were carried out on a friction pair to test its thermoelastic instability. Results show that as the value of each groove distribution parameter increases, the fitting curves of the average temperature, range, and the temperature inhomogeneity coefficient of the temperature field are in forms of oscillation. The average temperature and range have the same trends. The paper concludes that the average temperature range and inhomogeneity coefficient of the temperature field distribute in order, so that the optimized structural parameters were obtained.

Calculation of the Internal Temperature Field of Transformer by the Method of Combination the Finite Element and the Finite Volume

2014 ◽  
Vol 1079-1080 ◽  
pp. 492-497 ◽  
Author(s):  
Lun Ma ◽  
Liu Wang ◽  
Ying Ying Sun ◽  
Tao Wan ◽  
Jia Peng Wei ◽  
...  
Keyword(s):  
Temperature Field ◽  
Mixed Method ◽  
Hot Spot ◽  
Three Dimensional ◽  
Internal Temperature ◽  
Accurate Calculation ◽  
Calculation Results ◽  
Transformer Winding ◽  
Regulatory Model ◽  
Spot Temperature

Oil immersed transformer is an important equipment ofpower system, whose fault is often caused by the aging of insulation. In actualoperation, accurate calculation of the temperature field, especially hot spottemperature of transformer winding, is very important for stabilizing the powergrid operation and extending the transformer life. In order to calculate thetransformer's hot spot temperature accurately, a new method which is based oncomparison of respective advantages of the FEM and FVM is used; we take a31.5MVA transformer as exemple, using the hybrid method of the FEM and the FVM,the three-dimensional temperature field of transformer is calculated. Bycomparing the figures of top oil temperature of transformer monitored by theoperating transformer and the figures calculated by mixed method, the marginerror of the hot spot temperature is only 1.9°C. While the IEEE guidelines formodel calculation results, the calculated results of FEM algorithm and FVMalgorithm results with the monitoring data of standard deviation were as highas 4.6 °C, 3.8 °C and 3.1 °C. The Calculation accuracy is much higher than theaccuracy of the result using IEEE regulatory model, FEM and FVM, proved thatthis mixed method can calculate the internal temperature field of oil immersedtransformer accurately.

scholarly journals The study of three-dimensional temperature field distribution reconstruction using ultrasonic thermometry

AIP Advances ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 075007 ◽  
Author(s):  
Ruixi Jia ◽  
Qingyu Xiong ◽  
Kai Wang ◽  
Lijie Wang ◽  
Guangyu Xu ◽  
...  
Keyword(s):  
Temperature Field ◽  
Field Distribution ◽  
Three Dimensional ◽  
Temperature Field Distribution
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