Analytical analysis of transformer interaction caused by inrush current

This paper presents a preliminary study of sympathetic inrush -a phenomenon when an already energized transformer experiences unexpected saturation during the energizing of another transformer connected in parallel. Power transformer can be saturated, giving rise to transients which lead to overvoltage and overcurrent. With the increase of distributed generations that can exaggerate more switching events, transients will become prevalent in such an operating environment. This can also bring power quality variation. Detailed MATLAB-Simulink models are developed and a small scale laboratory experiment using two parallel transformers has been set up to observe the sympathetic inrush interaction and the effect of pointon-wave switching. The simulation results are presented and the analytical calculations are shown to be validated by experiment.

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“…At one point, the flux is zero; hence i 1 stops increasing [16]. The increase of i 1 and the decay of i 2 can be written as:…”

Section: Sympathetic Inrush Principlementioning

confidence: 98%

Investigation and modelling of sympathetic inrush due to transformer energization

Halim

Phung

Fletcher

2014

2014 International Conference on Smart Green Technology in Electrical and Information Systems (ICSGTEIS)

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“…The mechanism of sympathetic inrush for transformers in parallel has been investigated previously [12][13][14]. However, no study has been performed on transformers in series (called series transformers below).…”

Section: Introductionmentioning

confidence: 99%

Investigation into the Physical Mechanism and Influencing Factors of Sympathetic Inrush for Transformers in Series

Peng

Gao

2017

Mathematical Problems in Engineering

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Sympathetic inrush is a magnetizing inrush phenomenon generated in an in-service transformer, when a nearby transformer in series or in parallel is energized. This phenomenon lasts longer than the general inrush and can cause protection maloperation. The study focuses on sympathetic inrush in series transformers. Flux linkage expressions for the series transformers are derived using the Laplace transform. The residual flux, switching angle, and system impedance factors are included in the expressions. The physical mechanism of the sympathetic inrush for series transformers is explained based on the characteristics of the flux linkages. The interaction between the saturated transformers during sympathetic inrush is also investigated. Moreover, the influence of the switching angle, residual flux, system impedance, and load on the inrush currents is analyzed and validated.

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An Identification Method for Sympathetic Inrush Based on Substation-Area Information

Peng

Liu

Cheng

2019

2019 IEEE 8th International Conference on Advanced Power System Automation and Protection (APAP)

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Analytical analysis of transformer interaction caused by inrush current

Cited by 4 publications

References 11 publications

Investigation and modelling of sympathetic inrush due to transformer energization

Investigation and modelling of sympathetic inrush due to transformer energization

Investigation into the Physical Mechanism and Influencing Factors of Sympathetic Inrush for Transformers in Series

An Identification Method for Sympathetic Inrush Based on Substation-Area Information

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