Design of a digital protection scheme for power transformers using optimal state observers

1988 ◽  
Vol 135 (3) ◽  
pp. 224 ◽  
Author(s):  
Y.V.V.S. Murty ◽  
W.J. Smolinski ◽  
S. Sivakumar
Keyword(s):  
Power Transformers ◽  
Optimal State ◽  
Protection Scheme ◽  
State Observers ◽  
Digital Protection

A New Adaptive Differential Protection Scheme for Tap Changing Power Transformer

2015 ◽  
Vol 16 (4) ◽  
pp. 339-348 ◽  
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.

The Development of a $d$–$q$ Axis WPT-Based Digital Protection for Power Transformers

2012 ◽  
Vol 27 (4) ◽  
pp. 2255-2269 ◽  
Author(s):  
S. A. Saleh ◽  
A. Aktaibi ◽  
R. Ahshan ◽  
M. A. Rahman
Keyword(s):  
Power Transformers ◽  
Digital Protection

PSO trained ANN-based differential protection scheme for power transformers

2008 ◽  
Vol 71 (4-6) ◽  
pp. 904-918 ◽  
Author(s):  
M. Geethanjali ◽  
S. Mary Raja Slochanal ◽  
R. Bhavani
Keyword(s):  
Power Transformers ◽  
Differential Protection ◽  
Protection Scheme

Digital protection method for power transformers based on an equivalent circuit composed of inverse inductance

1988 ◽  
Vol 3 (4) ◽  
pp. 1501-1510 ◽  
Author(s):  
K. Inagaki ◽  
M. Higaki ◽  
Y. Matsui ◽  
K. Kurita ◽  
M. Suzuki ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Power Transformers ◽  
Protection Method ◽  
Digital Protection

scholarly journals Experimental investigation of insulation resistance for turbo generator digital protection

2020 ◽  
Vol 5 (2) ◽  
pp. 030-037
Author(s):  
Bernard Akindade Adaramola ◽  
Daniel Danjuma Chirpyen
Keyword(s):  
Insulation Resistance ◽  
Electrical Machinery ◽  
Experimental Procedure ◽  
Speed Test ◽  
Protection Scheme ◽  
Voltage Drops ◽  
Turbo Generator ◽  
Generator Unit ◽  
Insulation Breakdown ◽  
Digital Protection

Insulation of all electrical machinery is practically in the form of organic compounds that contain water as part of their make-up. Excessive temperature tends to dehydrate and oxidize the insulation and make it become brittle and disintegrate under vibration and shock. The insulation lifespan of turbo generators deteriorates slowly at low temperatures and more rapidly at high temperature. Economic factors, such as initial cost, replacement cost, obsolescence, and maintenance, are of prime importance when determining the years of useful service desired for the electrical insulation. Generator digital protection- fault diagnosis test was carried out to find out the cause of insulation breakdown on the turbo generator unit 411G3. The experimental procedure consists of an insulation resistance test, meggering (time-resistance absorption test), and pendulum over-speed test. A thorough investigation was conducted to identify all the stator bars that constituted the Red phase and other connections. Voltage drops on these stator bars were measured and values were used to detect ground faults which were rectified via an intelligent protection scheme.

scholarly journals Intelligent Protection of VSD Transformers

2020 ◽  
Vol 6 (4) ◽  
Author(s):  
Martin Brůha ◽  
Tore Nilsen
Keyword(s):  
Power Transformers ◽  
Design Practice ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Good Design ◽  
Transformer Protection ◽  
Protection Scheme ◽  
Harmonic Content ◽  
Input Transformer ◽  
Sinusoidal Current

Variable Speed Drives (VSD) protect themselves as well as the driven motors. In contrast, the isolation input transformer typically requires its dedicated protection. Unlike distribution and power transformers, the protection of VSD duty transformers need to consider several additional aspects, such as non-sinusoidal current with harmonic content, multi-winding design, phase-shifted converter windings etc. This paper aims to explain the challenges related to protection of VSD transformers. A guideline for reliable transformer protection based on good design practice is proposed. Finally the possibility to integrate the transformer protection into the VSD protection scheme is being explored.

Modeling and simulation of a communication-assisted digital protection scheme for micro-grids

2016 ◽  
Vol 57 ◽  
pp. 867-878 ◽  
Author(s):  
Sohrab Mirsaeidi ◽  
Dalila Mat Said ◽  
Mohd. Wazir Mustafa ◽  
Mohd. Hafiz Habibuddin ◽  
Kimia Ghaffari
Keyword(s):  
Modeling And Simulation ◽  
Protection Scheme ◽  
Digital Protection ◽  
Micro Grids
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