Performance of current transformer operate under harmonic condition and their effects on transformer differential protection

This paper focused to determine the performance of Current Transformer (CT) operates under harmonics condition and their effects on transformer differential protection. A laboratory test has been implemented to determine the error produced by both CT and power transformer when operating under harmonic condition. The test was performing with the actual condition, where the power transformer is connected to an adjusted nonlinear load, so that the test can be conducted with several levels of total harmonic distortion current (THDi). The results shows, for THDi ranging from 16.70% to 40.88% the maximum errors occurred on CT at secondary power transformers is 27.21% and CT at primary power transformers is 8.12%. This error resulted in differential current flow 0.17A and relay trip without any fault. In this study it was found that the relays started to operate incorrectly on THDi 31.5%.

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A power transformer differential protection based onsupport vector machine and wavelet transform

Electric Power Systems Research ◽

10.1016/j.epsr.2021.107297 ◽

2021 ◽

Vol 197 ◽

pp. 107297

Author(s):

Lucas D. Simões ◽

Hagi J.D. Costa ◽

Matheus N.O. Aires ◽

Rodrigo P. Medeiros ◽

Flavio B. Costa ◽

...

Keyword(s):

Wavelet Transform ◽

Power Transformer ◽

Differential Protection ◽

Transformer Differential Protection

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Transformer Differential Protection Using Process Bus According to IEC 61850-9-2 and Non-Conventional Instrument Transformers

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.799-800.1311 ◽

2015 ◽

Vol 799-800 ◽

pp. 1311-1315

Author(s):

G. Igarashi ◽

J.C. Santos

Keyword(s):

Time Synchronization ◽

Power Transformers ◽

Response Analysis ◽

Differential Protection ◽

Iec 61850 ◽

Instrument Transformers ◽

Synchronization Signal ◽

Conventional Instrument ◽

Transformer Differential Protection

Our aim is to show some impacts on the differential protection of power transformers when using Non-Conventional Instrument Transformers associated with the IEC 61850-9-2 process bus. Described herein are a model for simulating the samples in the process bus, a proposed algorithm for differential protection of power transformers adapted from conventional differential relays so that it works according to the IEC 61850-9-2 standard, and a response analysis of the protection algorithm with the loss of the time synchronization signal in the process bus. Suggestions on parameters to be followed for safer operation of the process bus in these circumstances are also offered.

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Parametric sensitivity analysis of power transformer differential protection

2017 Workshop on Communication Networks and Power Systems (WCNPS) ◽

10.1109/wcnps.2017.8252932 ◽

2017 ◽

Author(s):

L. M. Peres ◽

K. M. Silva

Keyword(s):

Sensitivity Analysis ◽

Power Transformer ◽

Differential Protection ◽

Parametric Sensitivity ◽

Parametric Sensitivity Analysis ◽

Transformer Differential Protection

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A Wavelet-Based Transformer Differential Protection With Differential Current Transformer Saturation and Cross-Country Fault Detection

2018 IEEE Power & Energy Society General Meeting (PESGM) ◽

10.1109/pesgm.2018.8586618 ◽

2018 ◽

Author(s):

Flavio Costa ◽

Rodrigo Prado

Keyword(s):

Fault Detection ◽

Current Transformer ◽

Differential Protection ◽

Cross Country ◽

Transformer Differential Protection ◽

Differential Current

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Enhancing Power Transformer Differential Protection to Improve Security and Dependability

IEEE Transactions on Industry Applications ◽

10.1109/tia.2017.2670525 ◽

2017 ◽

Vol 53 (3) ◽

pp. 2642-2649 ◽

Cited By ~ 6

Author(s):

Lubomir Sevov ◽

Umar Khan ◽

Zhiying Zhang

Keyword(s):

Power Transformer ◽

Differential Protection ◽

Transformer Differential Protection

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A New Adaptive Differential Protection Scheme for Tap Changing Power Transformer

International Journal of Emerging Electric Power Systems ◽

10.1515/ijeeps-2015-0005 ◽

2015 ◽

Vol 16 (4) ◽

pp. 339-348 ◽

Cited By ~ 2

Author(s):

Ashesh Mukeshbhai Shah ◽

Bhavesh Bhalja

Keyword(s):

Power Transformer ◽

Detection Sensitivity ◽

Power Transformers ◽

Test Cases ◽

Differential Protection ◽

Protection Scheme ◽

Differential Characteristic ◽

Numerous Test ◽

Internal Faults ◽

Conventional Scheme

Abstract This paper presents a new adaptive differential protection scheme which efficiently adapts the change in tap position of a power transformer. The proposed scheme is based on analytical derivation of pick-up and slope of the differential relay characteristic. By acquiring information such as rating & connection of CTs and present tap position as input, the proposed scheme enhances sensitivity of differential relay during internal faults. This is accomplished either by decreasing pick-up and/or adjusting slope of the differential characteristic of the relay in case of change in tap position. Numerous test cases consisting of various types of internal and external faults have been simulated for an existing power transformer of Gujarat Energy Transmission Corporation Limited (GETCO), Gujarat, India using PSCAD/EMTDC software package. The proposed scheme increases percentage of winding to be protected during internal faults for power transformers having different ratings and connections compared to the conventional differential protection scheme. Furthermore, it has been observed that the detection sensitivity during special types of turn-to-turn and inter-winding faults with varying fault resistances is also enhanced compared to the conventional scheme. Moreover, it equally maintains stability during CT saturation condition. At the end, comparative evaluation of the proposed scheme with the existing schemes clearly indicates superiority of the proposed adaptive scheme.

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