Behaviour of Internal Fault and External Fault in Power Transformer using Discrete Wavelet Transform

2012 ◽  
Author(s):  
Atthapol Ngaopitakkul ◽  
Chaichan Pothisarn
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Power Transformer ◽  
Discrete Wavelet ◽  
Internal Fault

A New Algorithm for Three-Phase Power Transformer Differential Protection Considering Effect of Ultra-Saturation Phenomenon Based on Discrete Wavelet Transform

2018 ◽  
Vol 20 (1) ◽  
Author(s):  
Bahram Noshad
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Power Transformer ◽  
Discrete Wavelet ◽  
Inrush Current ◽  
Differential Protection ◽  
Inductive Load ◽  
Saturation Phenomenon ◽  
Three Phase ◽  
Transformer Differential Protection

Abstract One of transient phenomena that lead to the false trip of the power transformer differential protection during the energization of a loaded power transformer is the ultra-saturation phenomenon. This paper presents, at first, a new algorithm for three-phase power transformer differential protection considering effect of the ultra-saturation phenomenon based on Discrete Wavelet Transform (DWT). To model the ultra-saturation phenomenon, the nonlinear characteristic of the transformer core and the effect of the saturation of the current transformers are taken into account. It is assumed that the load of the transformer is a resistive and inductive load. In this algorithm, the ultra-saturation phenomenon, the external and internal faults of power transformer and the magnetic inrush current are simulated. To distinguish between these phenomena, appropriate criteria using DWT by the use of standard deviation of coefficients are presented. Also, one of the most important criteria for the digital relays is the time for making a decision. Thus, to determine the time of decision, the experimental results will be presented.

A New Hybrid Protection Algorithm for Protection of Power Transformer Based on Discrete Wavelet Transform and ANFIS Inference Systems

2018 ◽  
Vol 19 (3) ◽  
Author(s):  
A.M. Salama ◽  
K. M. Abdel-Latif ◽  
Mohamed M. Ismail ◽  
S. M. Mousa
Keyword(s):  
Wavelet Transform ◽  
Response Time ◽  
Discrete Wavelet Transform ◽  
Power Transformer ◽  
Power Transformers ◽  
Discrete Wavelet ◽  
Inference System ◽  
Matlab Simulink ◽  
Inference Systems ◽  
High Degree

Abstract This paper presents a new protection algorithm for power transformers. The new algorithm is based on Discrete Wavelet Transform (DWT) and (ANFIS) Inference System. The simulation of power transformer is done using BCTRAN subroutine of ATP software to simulate the internal faults cases. The protection algorithm using DWT and ANFIS is implemented MATLAB Simulink software. The new Algorithm is tested on 40/40/15 MVA, 220/70/11.5 KV power transformer. The proposed algorithm satisfies high degree of accuracy and faster response time.

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