Analysis of the residual flux influence on inrush current and electromagnetic force in large power transformer

Ge, Weigao; Zhao, Jianhai; Wang, Youhua

doi:10.1049/joe.2018.8631

Cited by 12 publications

(2 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When the transformer is switched to connect with power grid again, a magnetizing inrush current will be produced as the existence of Br [7], [8]. Sometimes this current may be 6 to 8 times higher than the rated state current [9], which will result the transformer failing to connect with the power grid. To suppress inrush current, synchronous closing technology and phase selection closing technology are proposed in [10]- [12], on the premise of Br magnitude and direction being obtained [13].…”

Section: Introductionmentioning

confidence: 99%

Residual Flux Density Measurement Method of Single-Phase Transformer Core Based on Time Constant

Huo

Yang

et al. 2020

IEEE Access

Self Cite

View full text Add to dashboard Cite

Residual flux density in the single-phase transformer core can dramatically increase inrush current when the transformer is energized. To reduce inrush current, it is necessary to study residual flux density measurement. This paper proposes a new residual flux density measurement method based on time constant. Firstly, the generation principle of residual flux density is analyzed under different magnetization states, and it is found that the positive relative differential permeability is smaller than the negative at different residual flux density. To obtain the relative differential permeability, when an appropriate DC excitation is applied, the measurement circuit is equivalent to a first-order RL circuit. Then, combining magnetic circuit and transient circuit analysis, the relationship between time constant and relative differential permeability is obtained. It is conclusion that the positive time constant is less than the negative. Residual flux density direction is determined by comparing the positive and negative time constant, and the magnitude of residual flux density is calculated by the relationship between residual flux density and the difference of the positive and negative time constant. Finally, the empirical formula between residual flux density and time constant difference of the square core is obtained in finite element method, and then verified on the experimental platform. Compared with other measurement methods, the relative error of proposed empirical formula is within 4.58 %, and it has higher accuracy in this paper. The proposed method in this paper can provide a reference for selecting the demagnetization voltage, which improves the effectiveness of demagnetization. INDEX TERMS Residual flux density, relative differential permeability, time constant difference, empirical formula.

show abstract

Section: Introductionmentioning

confidence: 99%

Residual Flux Density Measurement Method of Single-Phase Transformer Core Based on Time Constant

Huo

Yang

et al. 2020

IEEE Access

Self Cite

View full text Add to dashboard Cite

show abstract

“…Differential relay should cater Vector Group of Transformer [14,15], Zero Sequence Current Flows [16], On Load Tap Changers [17], and must not initiate tripping during normal operation of transformer including energization of transformer (Inrush Current [18,19]), over fluxing [20], and tap changer operation.…”

mentioning

confidence: 99%

A Detailed Testing Procedure of Numerical Differential Protection Relay for EHV Auto Transformer

et al. 2021

View full text Add to dashboard Cite

In power systems, the programmable numerical differential relays are widely used for the protection of generators, bus bars, transformers, shunt reactors, and transmission lines. Retrofitting of relays is the need of the hour because lack of proper testing techniques and misunderstanding of vital procedures may result in under performance of the overall protection system. Lack of relay’s proper testing provokes an unpredictability in its behavior, that may prompt tripping of a healthy power system. Therefore, the main contribution of the paper is to prepare a step-by-step comprehensive procedural guideline for practical implementation of relay testing procedures and a detailed insight analysis of relay’s settings for the protection of an Extra High Voltage (EHV) auto transformer. The experimental results are scrutinized to document a detailed theoretical and technical analysis. Moreover, the paper also covers shortcomings of existing literature by documenting specialized literature that covers all aspects of protection relays, i.e., from basics of electromechanical domain to the technicalities of the numerical differential relay covering its detailed testing from different reputed manufacturers. A secondary injection relay test set is used for detailed testing of differential relay under test, and the S1 Agile software is used for protection relay settings, configuration modification, and detailed analysis.

show abstract

Effect of Tapping Position on the Electromagnetic Forces of the Tap-Winding Transformer

Dawood,

Bağrıyanık,

Kömürgöz

2024

J. Electr. Eng. Technol.

View full text Add to dashboard Cite

Analysis of the residual flux influence on inrush current and electromagnetic force in large power transformer

Cited by 12 publications

References 8 publications

Residual Flux Density Measurement Method of Single-Phase Transformer Core Based on Time Constant

Residual Flux Density Measurement Method of Single-Phase Transformer Core Based on Time Constant

A Detailed Testing Procedure of Numerical Differential Protection Relay for EHV Auto Transformer

Effect of Tapping Position on the Electromagnetic Forces of the Tap-Winding Transformer

Contact Info

Product

Resources

About