A New Wavelet Transform Approach to Discriminate Magnetizing Inrush Current and Fault Current

2006 ◽  
Author(s):  
X.L. Feng ◽  
J.C. Tan ◽  
Z.Q. Bo
Keyword(s):  
Wavelet Transform ◽  
Inrush Current ◽  
Fault Current ◽  
Magnetizing Inrush Current

scholarly journals A Method for Identification of Transformer Inrush Current Based on Box Dimension

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Maofa Gong ◽  
Ran Zheng ◽  
Linyuan Hou ◽  
Jingyu Wei ◽  
Na Wu
Keyword(s):  
Fundamental Difference ◽  
Box Dimension ◽  
Inrush Current ◽  
Fault Current ◽  
Differential Protection ◽  
Phase Current ◽  
Magnetizing Inrush Current ◽  
Three Phase ◽  
Transformer Differential Protection ◽  
Box Dimensions

Magnetizing inrush current can lead to the maloperation of transformer differential protection. To overcome such an issue, a method is proposed to distinguish inrush current from inner fault current based on box dimension. According to the fundamental difference in waveform between the two, the algorithm can extract the three-phase current and calculate its box dimensions. If the box dimension value is smaller than the setting value, it is the inrush current; otherwise, it is inner fault current. Using PSACD and MATLAB, the simulation has been performed to prove the efficiency reliability of the presented algorithm in distinguishing inrush current and fault current.

scholarly journals Differential Protection of Power Transformer using Wavelet Transform

2019 ◽  
Vol 8 (3) ◽  
pp. 7627-7630
Keyword(s):  
Wavelet Transform ◽  
Power Transformer ◽  
Circuit Breaker ◽  
Inrush Current ◽  
Differential Protection ◽  
Time Duration ◽  
Transform Method ◽  
Protection Scheme ◽  
Magnetizing Inrush Current ◽  
Clearing Time

This paper presents wavelet transform method for the analysis of differential currents of power transformer which can act as an accurate classifier between magnetizing inrush current and internal faults to avoid the needless tripping of circuit breaker. The differential protection scheme occasionally mal – operate whenever magnetizing inrush occurs in power transformer. The aim is to reduce the rate and time duration of undesired outages of power transformer. This includes the necessities of reliability with zero mal – operation of differential relay. The result shows higher operating speed with less fault clearing time. Wavelet Transform is employed for the analysis of transient signals under various conditions, which extracts data from signals in time and frequency domain simultaneously. The simulation is done in MATLAB environment.

scholarly journals Wavelet Transform Implementation to Differentiate Inrush Current and Fault Current in Power Transformer

2020 ◽  
Vol 8 (5) ◽  
pp. 3041-3044
Keyword(s):  
Fourier Transform ◽  
Wavelet Transform ◽  
Fast Fourier Transform ◽  
Power Transformer ◽  
Normal Faults ◽  
Inrush Current ◽  
Fault Current ◽  
Electrical System ◽  
Protection Circuit ◽  
Internal Faults

An electrical system is al complex network, to enhance power generation, transmission and distribution transformers play an important role. Power transformer is the heart of the electrical system. Even though electrical power is generated at lower rate in the coastal areas, it can be transmitted easily over hundreds of kilometer with the help of power transformer. So there must proper protection should given to power transformers. But in order to give the proper protection there should be proper discrimination between internal faults and inrush current. If there is no proper differentiation between faults and inrush current phenomena than the protection circuit will not trip when inrush current comes into the picture. But the protection circuit will trip at faster rate than the actual one when the normal faults or internal faults come into the picture. So there should be proper discrimination between inrush current and internal fault current so that the protection circuit will work properly. There are so many techniques available to get differentiation between inrush current and fault current. Fast Fourier transform is one of the method to differentiate between these two currents. Here we are using wavelet transform technique to get the difference between these two currents. The properties of the inrush current obtained from this technique are accurate and distinct from those obtained from the fast Fourier transform. The experimental set up is carried out in matlab simulink and results were discussed as shown below in results.

Identifying Transformer Inrush Current Based on Artificial Neural Network

2011 ◽  
Vol 58-60 ◽  
pp. 1779-1785
Author(s):  
Hang Xu ◽  
Xu Hong Yang ◽  
Jian Hua Ye ◽  
Hong Qian ◽  
Yang Xue ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
High Accuracy ◽  
Inrush Current ◽  
Fault Current ◽  
Neural Network Method ◽  
Magnetizing Inrush Current ◽  
Network Method ◽  
Simulation Results ◽  
Digital Simulations

In this paper, lots of digital simulations of transformer magnetizing inrush current and fault current have been done through Matlab software. A neural network method used to identify magnetizing inrush current has been proposed and established. The simulation results show that this method can identify magnetizing inrush current well, with high accuracy.

Research on Identifying Inrush Current of Transformer Based on Correlation Analysis

2012 ◽  
Vol 433-440 ◽  
pp. 6921-6926
Author(s):  
Da Zhuang Chen ◽  
Jia Dong Huang
Keyword(s):  
Correlation Analysis ◽  
Correlation Coefficient ◽  
Inrush Current ◽  
Fault Current ◽  
Full Wave ◽  
Fault Currents ◽  
Magnetizing Inrush Current ◽  
Half Wave ◽  
Frequency Components ◽  
Fourier Algorithm

This paper presents correlation analysis to discriminate the magnetizing inrush current from the fault currents in transformers. The proposed technique is based on the normalized correlation coefficient flowing into transformers during the fault current or the transformer inrush current. The method need the imaginary parts of fundamental frequency components, which are obtained from sampling differential current based on full-wave fourier algorithm and half-wave fourier algorithm, then calculate the normalized correlation coefficient with theory of correlation coefficient. Theoretical analysis and dynamic simulation results show that the method is effective and reliable under various fault conditions and simple to be applied.

An Identification Method of Magnetizing Inrush Current Phenomena in Distribution System

2010 ◽  
Vol 130 (4) ◽  
pp. 430-436 ◽  
Author(s):  
Naoki Dou ◽  
Atushi Toyama ◽  
Kohki Satoh ◽  
Tadashi Naitoh ◽  
Kazuyuki Masaki
Keyword(s):  
Distribution System ◽  
Inrush Current ◽  
Identification Method ◽  
Magnetizing Inrush Current
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