An improved thermal model for distribution transformer under unbalanced voltage conditions

Najafi, Atabak; İskender, İres

doi:10.1016/j.ijthermalsci.2015.11.014

Cited by 17 publications

(7 citation statements)

References 9 publications

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“…The second way is to use the temperature profiles to validate the results of this study. The maximum temperature of the core and the oil temperature at different loads are within the maximum range, as measured in previous studies . The thermal limits of the transformer used in this work are within the range of several guidelines, such as those provided by the IEEE standard C57.91‐1995…”

Section: Validation Worksupporting

confidence: 71%

“…The maximum temperature of the core and the oil temperature at different loads are within the maximum range, as measured in previous studies. [56][57][58][59] The thermal limits of the transformer used in this work are within the range of several guidelines, such as those provided by the IEEE standard C57.91-1995. 60 Numerous parameters, such as losses and thermal profiles, should be considered when determining the optimum T-joint design for the core of the transformer.…”

Section: Temperature Profile Resultsmentioning

confidence: 99%

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A new approach of core structure model for 3-phase distribution transformer

Alyozbaky

Kadir

Izadi

et al. 2018

Int Trans Electr Energ Syst

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Summary Reducing the losses of 3‐phase transformers is still considered a significant target by many transformer designers and manufacturers. Core joint design is one of the factors related to the losses. In previous studies, core losses and flux density distribution motivated researchers to design appropriate T‐joints. However, the variation of load and thermal profiles are the most important factors related to the losses in transformers. This study proposed a new T‐joint configuration for the core of the 3‐phase transformer. The proposed model was built after considering the variation of load and thermal profiles. Results were compared with those of conventional T‐joint designs, such as butt‐lap and 45° mitered designs, that are currently used. The no‐load losses of the proposed model were reduced by more than 6.8% and 10% compared with those of the butt‐lap and mitered T‐joint designs, respectively. Furthermore, the total losses, the hot spot temperature of the core, and the oil temperature decreased significantly. The proposed model contributes to the literature on new T‐joint designs for improving transformer performance.

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Section: Validation Worksupporting

confidence: 71%

Section: Temperature Profile Resultsmentioning

confidence: 99%

A new approach of core structure model for 3-phase distribution transformer

Alyozbaky

Kadir

Izadi

et al. 2018

Int Trans Electr Energ Syst

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“…Genetic algorithm may be employed to extend the TEC in order to estimate the above-mentioned parameters [11,12]. Later on, extended TEC of power transformer did not model different parts individually and merely hot spot of winding and top-oil temperature within the transformer were determined [13][14][15]. However, presented models have not been so far used for thermal analysis of transformer supplied by unbalanced voltages, because they have some limitations for such applications.…”

Section: Introductionmentioning

confidence: 99%

Thermal analysis of power transformers under unbalanced supply voltage

Mikha-Beyranvand

Faiz

Rezaeealam

et al. 2019

IET Electric Power Applications

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High temperatures may damage power transformers. These problems leading to the high temperature are more revealed under non-rating operating conditions such as unbalanced supply voltage. The aim of the present study is thermal analysis of such supply and obtaining its temperature distribution. Existing thermal analysis methods through thermal equivalent circuit (TEC) have some drawbacks; in these models, thermal parameters of different regions of transformer such as core, tank, metallic parts and winding are not defined. On the other hand, those models are not applicable for thermal analysis of transformer with unbalanced supply voltage. Here, a novel TEC model is proposed which is able to define temperatures of different components of oil-immersed power transformers individually under unbalanced supply voltage. The merit of the introduced model is that losses of different parts of transformer are considered as heat generating sources which are used as the inputs of thermal model. At this end, a three-dimensional finite-element method is suggested which is able to estimate the losses of different parts of power transformer. Finally, the results of applying the TEC to the transformer are compared with the temperature distribution of finite-element modelling and high accuracy of the TEC model in estimation of the temperatures of different regions are emphasised.

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“…Oil-immersed power transformer insulation often uses oil-paper insulation structure type. In this case temperature is the main factor to promote the aging [1] . Hot spot is not only the most serious areas where insulation state is affected by temperature, but oil and paper insulation aging are one of the fastest [2] .…”

Section: Introductionmentioning

confidence: 99%

Research on Hot Spot Temperature Calculation and Analysis of Online Monitoring Method of Oil-immersed Power Transformer Winding

Zhang¹

2017

Proceedings of the 2nd International Conference on Computer Engineering, Information Science &Amp; Application Technology (ICCI

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Abstract. Transformer hot spot temperature is the most important reason for affecting the insulation state of the winding. Hot spot position is also one of the most serious areas in transformer oil paper insulation aging. Therefore, to monitor the hot point temperature is of great significance. This paper introduces the indirect calculation model of hot spot temperature of oil-immersed power transformer and the real-time on-line monitoring system. Subsequently the simulation of transformer hot spot temperature instance is enumerated with the MATLAB environment.

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An improved thermal model for distribution transformer under unbalanced voltage conditions

Cited by 17 publications

References 9 publications

A new approach of core structure model for 3-phase distribution transformer

A new approach of core structure model for 3-phase distribution transformer

Thermal analysis of power transformers under unbalanced supply voltage

Research on Hot Spot Temperature Calculation and Analysis of Online Monitoring Method of Oil-immersed Power Transformer Winding

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