Evaluation of the Power Transformer Magnetizing Inrush Currents

2020 ◽  
Vol 10 (10) ◽  
pp. 20-32
Author(s):  
Aleksey A. KUVSHINOV ◽  
◽  
Vera V. VAKHNINA ◽  
Aleksey N. CHERNENKO ◽  
◽  
...  
Keyword(s):  
Power Transformer ◽  
Geomagnetic Disturbance ◽  
Inrush Current ◽  
Geomagnetic Disturbances ◽  
Disturbance Intensity ◽  
Magnetizing Inrush Current ◽  
Inrush Currents ◽  
Instantaneous Values ◽  
The Mathematical Model ◽  
Analytical Expressions

The mathematical model of a shell-core power transformer’s magnetization branch is substantiated. By using the model, analytical expressions for the magnetizing current instantaneous values under the conditions of geomagnetic disturbances can be obtained. Quantitative assessments of the magnetizing inrush current amplitudes and durations versus the geomagnetic disturbance intensity are obtained. The dynamics of the power transformer magnetic system saturation transient and changes in the magnetization inrush current amplitudes and durations after a sudden occurrence of geomagnetic disturbances are shown. The error of estimating the magnetizing inrush current amplitudes under geomagnetic disturbances is determined based on comparison with experimental data.

scholarly journals Simulink model of transformer differential protection using phase angle difference based algorithm

2020 ◽  
Vol 11 (2) ◽  
pp. 1088
Author(s):  
Nassim A. Iqteit ◽  
Khalid Yahya
Keyword(s):  
Phase Angle ◽  
Power Transformer ◽  
Inrush Current ◽  
Current Transformers ◽  
Phase Angle Difference ◽  
Simulink Model ◽  
Magnetizing Inrush Current ◽  
Angle Difference ◽  
Inrush Currents ◽  
Transformer Differential Protection

<p class="p1">An application of phase-angle-difference based algorithm with percentage differential relays is presented in this paper. In the situation where the transformer differential relay is under magnetizing inrush current, the algorithm will be utilized to block the process. In this study, the technique is modeled and implemented using Simulink integrated with MATLAB. The real circuit model of power transformer and current transformers are considered in the simulation model. The results confirmed the effectiveness of the technique in different operation modes; such as, magnetizing inrush currents, current transformers saturation and internal transformer faults.</p>

scholarly journals The Assessment of a Magnetizing-Current Inrush of a Power Transformer

2021 ◽  
Vol 2096 (1) ◽  
pp. 012135
Author(s):  
A Kuvshinov ◽  
V Vakhnina ◽  
D Kretov ◽  
A Chernenko
Keyword(s):  
Power Transformer ◽  
Piecewise Linear ◽  
Current Amplitude ◽  
Piecewise Linear Approximation ◽  
Inrush Current ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Disturbances ◽  
Magnetizing Inrush Current ◽  
Magnetizing Current ◽  
Induced Currents

Abstract The study aims to propose an analytical tool for determining the parameters of the power transformer magnetizing inrush current caused by geomagnetically induced currents flowing through high-voltage windings with a grounded neutral under the impact of geomagnetic disturbances on the power grid. The analytical equations for the instantaneous magnetizing current under geomagnetic disturbances were obtain by mathematical model of magnetizing branch for a shell-type power transformer. A model base on a magnetization characteristics piecewise-linear approximation for the electrical steel. The magnetizing inrush current amplitude and duration it was found depends on the intensity of geomagnetic disturbances and in cope-link with the dynamics of the power transformer core saturation transient process were determined the changes in the magnetizing inrush current amplitude and duration under geomagnetic disturbances. The magnetizing inrush current amplitude it was found may reach the level of short-circuit current periodic component at the point of power transformer grid connection. The results were verify by comparing the design and experimental values of the magnetizing inrush current amplitude. The advantages of proposed mathematical model shown with justifying the analogy between core saturation under connecting of power transformer to a grid and under geomagnetically induced currents exposed. The piecewise-linear approximation of power transformer magnetization characteristic, allow to obtain the amplitude value of magnetizing inrush current caused by geomagnetically induced currents with an accuracy of 6% and can be used with power grid steady state and transient simulation under geomagnetic disturbances.

scholarly journals Analysis of the Electromechanical Characteristics of Power Transformer under Different Residual Fluxes

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8244
Author(s):  
Wenqi Ge ◽  
Chenchen Zhang ◽  
Yi Xie ◽  
Ming Yu ◽  
Youhua Wang
Keyword(s):  
Power Transformer ◽  
Input Parameter ◽  
Electromagnetic Transients ◽  
Structural Parameter ◽  
Inrush Current ◽  
Parameter Variations ◽  
Inrush Currents ◽  
3D Finite Element Method ◽  
Opening And Closing ◽  
The Impact

When the electromagnetic transients occur in a power transformer, an inrush current is generated in its winding. The inrush current not only affects the performance of the transformer windings, but also affects the lifetime of the transformer. Many factors affect the inrush current, the most influential ones among which are the closing phase angle and the residual flux. In this paper, a dry-type transformer simulation model is built to analyze the influence of the inrush current on the performance of transformer windings during no-load reclosing conditions. Firstly, the inrush current was generated in the transformer windings during the no-load reclosing operation under different residual fluxes. Secondly, the field-circuit coupling 3d finite element method is used to analyze the electromagnetic force at different locations of the transformer windings under the influence of different inrush currents. The results of winding structural parameter variations are obtained through electromagnetic-structural coupling simulation, and the electromagnetic forces are used as the input parameter for the structural analysis. Finally, the residual flux is generated by controlling the opening and closing angle of the transformer through the phase-controlled switch, and the winding electromechanical characteristics are tested under different residual fluxes. Finally, comparisons of the test and simulation results are drawn to verify the impact of the closing angle and residual flux on inrush current and the winding deformation during the no-load reclosing conditions.

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 Comparison and Analysis of Magnetizing Inrush and Fault Condition for Power Transformer

2018 ◽  
Vol 7 (4.5) ◽  
pp. 126 ◽  
Author(s):  
Mudita Banerjee ◽  
Dr. Anita Khosla
Keyword(s):  
Fourier Transform ◽  
Normal Condition ◽  
Power Transformer ◽  
Harmonic Distortion ◽  
Inrush Current ◽  
Harmonic Content ◽  
Internal Fault ◽  
Magnetizing Inrush Current ◽  
Comparison And Analysis ◽  
Primary Current

This paper presents the second harmonics present in the primary current of a power transformer at different conditions using Fast Fourier Transform and Total Harmonic Distortion techniques to analyze the inrush condition and to distinguish it with fault condition of a power transformer. Result shows that the 2nd harmonic content is pre-dominant in inrush condition of primary current of the power transformer. It is observed that there are significant differences amongst the parameters found during inrush condition, normal condition and internal fault condition which are useful in the identification of magnetizing inrush current of power transformer. The simulation is done in MATLAB/SIMULINK. 

scholarly journals Design of Hardware Setup Based on IEC 61850 Communication Protocol for Detection & Blocking of Harmonics in Power Transformer

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8284
Author(s):  
Abdul Azeem ◽  
Majid Jamil ◽  
Shamimul Qamar ◽  
Hasmat Malik ◽  
Rayees Ahmad Thokar
Keyword(s):  
Research Study ◽  
Communication Protocol ◽  
Power Transformer ◽  
Object Oriented ◽  
Power Transformers ◽  
Inrush Current ◽  
Iec 61850 ◽  
Transformer Protection ◽  
Magnetizing Inrush Current ◽  
Harmonic Restraint

In this paper, the authors have developed a hardware model for blocking even and odd harmonics of a power transformer. In the proposed hardware model, intelligent differential & over-current relays are used for the blocking of harmonics of a power transformer. The harmonic restraint function on the differential relay (7UT61) prevents the relay from tripping during transformer magnetizing inrush current. However, the over-current relays which are used for back up protection does not have a harmonic restraint element, and over-current relay trips due to magnetizing inrush current, causes unwanted interruptions and power failures. The establishment of harmonic blocking scheme for over-current protection in power transformers is an important finding of this research study. IEC61850 standard-Based GOOSE (Generic Object Oriented Substation Event) applications used in power transformer protection for fast detecting and clearing of faults is an interested study presented in the proposed work.

Sign in / Sign up

Export Citation Format

Share Document