Paper 12: Determination of the ‘Hot Spot’ Temperature Rise from P.V.C. Insulation Characteristics

1969 ◽  
Vol 184 (11) ◽  
pp. 117-130
Author(s):  
S. W. Twaites ◽  
R. F. Murray
Keyword(s):  
High Temperature ◽  
Temperature Rise ◽  
Hot Spot ◽  
Electrical Machines ◽  
Maximum Temperature ◽  
Spot Temperature ◽  
Operational Service

It is normal practice when designing electrical machines to design for operation within the maximum temperature limits of the insulation. If part of the winding is not effectively cooled under these conditions, the resulting temperature rise can damage the insulation and seriously reduce the length of operational service of the machine. This paper discusses a method of detecting high-temperature regions within a winding and of estimating the ‘hot spot’ temperature. The investigation has been concentrated on the design associated with a direct water-cooled winding, although the results could be applied generally on other electrical machines.

scholarly journals Study on the Method of Calculating Temperature Rise of Transformer

2020 ◽  
Vol 179 ◽  
pp. 01027
Author(s):  
Tao Li ◽  
Xiaoping Du ◽  
Xuewu Sun ◽  
Yuanyuan Song
Keyword(s):  
Temperature Rise ◽  
Thermal State ◽  
Hot Spot ◽  
Scientific Basis ◽  
Internal Temperature ◽  
Insulation Aging ◽  
The Neural Network ◽  
Forecasting Method ◽  
Transformer Winding ◽  
Spot Temperature

The internal temperature of the transformer is a key parameter to measure the thermal state of the transformer. The service life of the transformer generally depends on the life of the insulating material, and high temperature is the main reason why cause insulation aging, this paper studies the temperature rise of transformer winding hot spot temperature for the key, using the neural network forecasting method, forecasts transformer winding hot spot temperature change rule, calculate the transformer internal temperature rise, provide the temperature of the scientific basis for the safe operation of the transformer.

A Novel Approach to Investigate the Hot-Spot Temperature Rise in Power Transformers

2015 ◽  
Vol 51 (3) ◽  
pp. 1-4 ◽  
Author(s):  
Longnv Li ◽  
Shuangxia Niu ◽  
S. L. Ho ◽  
W. N. Fu ◽  
Yan Li
Keyword(s):  
Temperature Rise ◽  
Hot Spot ◽  
Power Transformers ◽  
Novel Approach ◽  
Spot Temperature

scholarly journals Initiation of solid explosives by impact and friction: the influence of grit

1949 ◽  
Vol 198 (1054) ◽  
pp. 337-349 ◽  
Keyword(s):  
Melting Point ◽  
Hot Spots ◽  
Hot Spot ◽  
Threshold Value ◽  
Maximum Temperature ◽  
Melting Points ◽  
Solid Explosives ◽  
Lower Melting Point ◽  
Determining Factor ◽  
Spot Temperature

This paper describes an experimental study of the initiation of solid explosives, and in particular the effect of artificially introducing transient hot spots of known maximum temperature. This was done by adding small foreign particles (or grit) of known melting-point. The minimum transient hot-spot temperature for the initiation of a number of secondary and primary explosives has been determined in this way. It is shown that the melting-point of the grit is the determining factor , and all the grits which sensitize these explosives to initiation either by friction or impact have melting-points above a threshold value which lies between 400 and 550 ° C. Grit particles of lower melting-point do not sensitize the explosives. The same explosives initiated by the adiabatic compression of air required, for initiation, minimum transient temperatures of the same order as the threshold melting-point values. The results provide strong evidence that the initiation of solids as well as of liquids by friction and impact is thermal in origin and is due to the formation of localized hot spots. There is evidence that in the case of the majority of secondary explosives which melt at comparatively low temperatures, intergranular friction is not able to cause explosion and the hot spots must be formed in some other way. With the primary explosives which explode at temperatures below their melting-points, hot spots formed by intergranular friction can be important.

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.

Thermal Model of Disk Coil With Directed Oil Flow

2008 ◽  
Author(s):  
Shahram Khalil Aria ◽  
Sahar Samsami
Keyword(s):  
Mathematical Model ◽  
Optimal Design ◽  
Temperature Rise ◽  
Thermal Model ◽  
Hot Spot ◽  
Exact Location ◽  
Oil Flow ◽  
Transformer Winding ◽  
Spot Temperature

In this paper, a developed mathematical model for temperature rise calculation is briefly described. In this model, at first, load loss of a transformer winding with forced directed oil is calculated and the winding temperature rise along the horizontal ducts and vertical ducts is computed. Then hot spot temperature and its exact location is determined. The model can also be used for optimal design of winding in size and cooling. Finally the results are given and compared with experiment values.

scholarly journals Analysis and Experiment of Hot-Spot Temperature Rise of 110 kV Three-Phase Three-Limb Transformer

Energies ◽  
2017 ◽  
Vol 10 (8) ◽  
pp. 1079 ◽  
Author(s):  
◽  
◽  
◽  
◽  
◽  
...  
Keyword(s):  
Temperature Rise ◽  
Hot Spot ◽  
Three Phase ◽  
Spot Temperature

The effect of high-temperature steam ingestion on aerodynamic performance and stability of a transonic rotor

2018 ◽  
Vol 233 (9) ◽  
pp. 3351-3367 ◽  
Author(s):  
Baofeng Tu ◽  
Luyao Zhang ◽  
Jun Hu
Keyword(s):  
High Temperature ◽  
Temperature Rise ◽  
Mass Fraction ◽  
Stability Boundary ◽  
Maximum Temperature ◽  
Aerodynamic Stability ◽  
Rise Rate ◽  
High Temperature Steam ◽  
The Impact ◽  
Transonic Rotor

To investigate the effect of high-temperature steam ingestion on the aerodynamic stability of a transonic axial compressor, a NASA Rotor 37 was numerically simulated. The effects of the high-temperature steam mass fraction, the temperature rise rate, the maximum temperature, and the distribution of steam at the inlet boundary on the aerodynamic stability of a transonic axial rotor were investigated, using the steady-state and quasi-steady methods. From the simulation results, it was found that high-temperature steam ingestion has an adverse effect on the transonic rotor. The greater the steam mass fraction and the maximum temperature, the greater the impact of the steam ingestion on the stability boundary. The temperature rise rate has little effect on the performance and stability. The distribution of steam at the inlet boundary has a significant impact on the performance and stability. In addition, with the ingestion of high-temperature steam, the average density of the gas at the rotor inlet is affected, and the passage shock position moves forward at the same time, which leads to the occurrence of the stall in advance.

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