Eccentric Bus-Bar Testing Method of the Shielding Effect of a Heavy Current Transformer With Shielding Coils

Qu, Kaifeng; Zhao, Wei; Huang, Songling; Jiang, Bo; Liu, Zhifang; Dong, Qinxiao

doi:10.1109/tim.2011.2160913

Cited by 5 publications

(5 citation statements)

References 4 publications

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“…Furthermore, in [ 16 ], the leakage flux produced by an eccentric primary bus-bar is also derived from the vector potential method, as shown in Equation (4).

where d is the eccentric distance of the bus-bar, i 1 is the bus-bar current, and k e is the core-pickup factor for the leakage flux produced by the eccentric bus-bar, which has been estimated to be almost the same as k s by simulation and experimental results demonstrated in previous publications [ 15 , 17 ].…”

Section: Analytical Models Of the Stray Flux And Coil Leakage Fluxmentioning

confidence: 98%

“…To propose a new empirical equation for the currently used mainstream CTs, sufficient empirical data are required. The empirical data can be obtained by numerical simulation based on the finite-element method (FEM), a method that has been proven to be highly accurate in solving stray flux in a CT core [ 17 ].…”

Section: Analytical Models Of the Stray Flux And Coil Leakage Fluxmentioning

confidence: 99%

“…In order to model this open boundary problem, a large cylindrical air region was built, with the ring core object horizontally placed at the center of the region. The radius and the height of the cylindrical air region were respectively set to 4 m and 5 m, which had been validated to be accurate enough for this analysis [ 17 ]. The ring core object was meshed into approximate 10 × 10 × 10 mm cubic elements, and the air region was meshed freely in default parameters.…”

Section: Analytical Models Of the Stray Flux And Coil Leakage Fluxmentioning

confidence: 99%

“…However, so far, quantified studies on the performance of shielding coils are limited in number and scope. Due to the lack of analytical models, existing studies on the stray flux and the leakage flux of shielding coils are mainly based on physical experiments [ 1 , 4 , 10 , 13 , 14 , 15 ] or numerical calculations [ 9 , 11 , 13 , 14 , 16 , 17 , 18 ], both of which take a lot of time to process [ 19 ]. This problem is especially pronounced in the optimization of shielding coils, where thousands of cases are to be inspected [ 20 ].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers

Gao

Zhao

Wang

et al. 2017

Sensors

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Applying shielding coils is a practical way to protect current transformers (CTs) for large-capacity generators from the intensive magnetic interference produced by adjacent bus-bars. The aim of this study is to build a simple analytical model for the shielding coils, from which the optimization of the shielding coils can be calculated effectively. Based on an existing stray flux model, a new analytical model for the leakage flux of partial coils is presented, and finite element method-based simulations are carried out to develop empirical equations for the core-pickup factors of the models. Using the flux models, a model of the common four-segment shielding coils is derived. Furthermore, a theoretical analysis is carried out on the optimal performance of the four-segment shielding coils in a typical six-bus-bars scenario. It turns out that the “all parallel” shielding coils with a 45° starting position have the best shielding performance, whereas the “separated loop” shielding coils with a 0° starting position feature the lowest heating value. Physical experiments were performed, which verified all the models and the conclusions proposed in the paper. In addition, for shielding coils with other than the four-segment configuration, the analysis process will generally be the same.

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“…Furthermore, in [ 16 ], the leakage flux produced by an eccentric primary bus-bar is also derived from the vector potential method, as shown in Equation (4).

Section: Analytical Models Of the Stray Flux And Coil Leakage Fluxmentioning

confidence: 98%

Section: Analytical Models Of the Stray Flux And Coil Leakage Fluxmentioning

confidence: 99%

Section: Analytical Models Of the Stray Flux And Coil Leakage Fluxmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers

Gao

Zhao

Wang

et al. 2017

Sensors

Self Cite

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show abstract

“…In [11], a method is proposed to simplify the multi-phase interference into a stray field produced by a single large current, but still a large current source as well as bulky bus-bars are required in the testing [12][13][14]. On the other hand, the principle of shielding coils can also be applied, i.e., introducing a set of partial testing coils to generate an equivalent interfering magnetic field.…”

Section: Introductionmentioning

confidence: 99%

Design of equivalent coils for anti- interference testing of heavy current transformers

Gao

Zhao

Qu³

et al. 2018

International Journal of Applied Electromagnetics and Mechanics

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Heavy current transformers (HCTs) for large generators are intensively interfered by the stray magnetic field produced by heavy adjacent currents, and therefore, anti-interference testing is a crucial process to assure the robustness of HCT products. However, the generation of the interference involves multiphase heavy currents, which are difficult to produce in testing environments, and equivalent testing coils have become an emerging solution to the testing. In this paper, an improved parameter determination algorithm is proposed for the traditional two-segment testing coil configuration, and furthermore, a novel multi-segment testing coil configuration is proposed for better equivalence of the multiphase interference. The effectiveness of the two configurations are thoroughly analyzed by FEM-based simulations as well as physical experiments.

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The effect of interfering flux on direct current comparator

Shao

Pan

et al. 2010

Cpem 2010

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Eccentric Bus-Bar Testing Method of the Shielding Effect of a Heavy Current Transformer With Shielding Coils

Cited by 5 publications

References 4 publications

Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers

Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers

Design of equivalent coils for anti- interference testing of heavy current transformers

The effect of interfering flux on direct current comparator

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