Statistical study of power transformer controlled switching with circuit breaker characteristics considerations

2010 ◽  
Author(s):  
T. Liu ◽  
M. Petit ◽  
H. Siguerdidjane ◽  
T. Jung
Keyword(s):  
Statistical Study ◽  
Power Transformer ◽  
Circuit Breaker ◽  
Controlled Switching

Implementation of power transformer controlled switching algorithm

2016 ◽  
Vol 35 (4) ◽  
pp. 1418-1427 ◽  
Author(s):  
Jacek Horiszny
Keyword(s):  
Power Transformer ◽  
Circuit Breaker ◽  
Electric Circuit ◽  
Circuit Theory ◽  
Electromagnetic Transients ◽  
Inrush Current ◽  
Content Type ◽  
Controlled Switching ◽  
Mathematical Formulas ◽  
The Times

Purpose – The paper presents two new algorithms of controlled switching the power transformer. The purpose of this paper is to obtain formulas that determine the moments of closing of the circuit breaker poles. The study contains projects of control systems for both algorithms. Design/methodology/approach – Mathematical formulas for the time instants of the breaker poles closing were developed on the basis of electric circuit theory and magnetic circuit theory. The presented systems were simulated using a model created in the Alternative Transients Program/Electromagnetic Transients Program software. Findings – Numerical simulations have proved that the shown systems properly perform the controlled switching carried out in accordance with the proposed algorithms. The times of the poles closing were correctly determined and the inrush currents were reduced to a level of the current of unloaded transformer. Originality/value – The results achieved are better than those shown in the literature. The solutions presented in the literature provide a reduction of inrush current to a value comparable to the rated current of the transformer, which is ten times greater than the no-load current. Additional achievement of the work is the development of analytical formulas that determine the times of the breaker poles closing.

Electric Discharges Localization for Substation Fault Monitoring Using Two Elements Sensor

2020 ◽  
Vol 17 (2) ◽  
pp. 1009-1013
Author(s):  
Lorothy Morrison Buah Singkang ◽  
Kismet Anak Hong Ping ◽  
P. R. P. Hoole
Keyword(s):  
Fault Detection ◽  
Power Transformer ◽  
Circuit Breaker ◽  
Electric Power System ◽  
Array Antenna ◽  
Electric Discharges ◽  
Localization Accuracy ◽  
Fault Monitoring ◽  
Electromagnetic Signals ◽  
Element Array

A substation is an important unit in the electric power system. Thus, the monitoring process must be carried out effectively to detect the operation status of the equipment, and pre-fault threat detection is necessary for safe operation. Many methods and intelligent techniques have been developed to provide a better way of fault detection. However, power authorities unwilling to adopt those techniques due to the high cost of installation and more sensors required to improve localization accuracy. Therefore, to reduce cost and increase the speed of detection, this paper presents a 2-element array antenna acted like a sensor to detect and localize the electric discharges from abnormal radiated electromagnetic activities in the substation based on the direction of arriving angle (DOA) received by the array antenna. Software implemented signal processor was used to obtain the radiation patterns for different value of DOA relative to the normalized Array Factor (AFN). This 2-element Sensor was proven to eliminate the undesired signals (such as electromagnetic signals from outside the substation) and maximize the signals in the direction of the desired signal by detecting the DOA of abnormal radiation from power apparatus (such as power transformer or circuit breaker bushings) inside the substation. It was proven that this cohesive unit was able to perform the two tasks by simultaneously eliminating or maximizing signals with very small (such as 0.0873 radians) angle difference between external radiation and radiation from apparatus inside the substation. By performing these tasks, the 2-element Sensor was promisingly able to detect and localize the abnormal electrical activities such as Electric Corona and Electric Arcs discharges that may occur in any substation based on the identified DOA from the power apparatus within the substation as a preventative approach for substation breakdown and to improve the efficiency and the performance of fault detection technique in future Substation Fault Monitoring.

Prevention of reignition overvoltages by phase-angle-controlled switching of a gas circuit breaker at shunt reactor current interruption

1993 ◽  
Vol 113 (5) ◽  
pp. 14-23
Author(s):  
Yoshifumi Yamagata ◽  
Tsutomu Kumagai ◽  
Susumu Nishiwaki ◽  
Hiroaki Toda ◽  
Masayuki Ishikawa ◽  
...  
Keyword(s):  
Phase Angle ◽  
Circuit Breaker ◽  
Current Interruption ◽  
Shunt Reactor ◽  
Controlled Switching

A New Differential Relay Framework for Power Transformer

2014 ◽  
Vol 492 ◽  
pp. 426-430
Author(s):  
Rachid Bouderbala ◽  
Hamid Bentarzi
Keyword(s):  
Power Transformer ◽  
Circuit Breaker ◽  
Differential Protection ◽  
Test Results ◽  
Transient Currents ◽  
Fault Currents ◽  
Internal Fault ◽  
Time Signals ◽  
Data Acquisition Card ◽  
Frame Work

A differential relay that is very sensitive relay operating even at its limits may be used for protecting a power transformer. However, this characteristic may lead to unnecessary tripping due to transient currents. In order to avoid this unnecessary tripping, estimated harmonics of these currents may be required which need great computation efforts. In this paper, a new frame work is proposed using PC interfaced with a data acquisition card AD622, which acquires real-time signals of the currents, process them numerically in the computer and outputs tripping signal to the circuit breaker. All algorithms of differential protection function and blocking techniques have been implemented using the Simulink/Matlab. To validate the present work, the performance of developed relay is tested by signals generated by Simulink/MATLAB simulator under different conditions. The test results show that this proposed scheme provides good discrimination between the transient currents and the internal fault currents.

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.

Sign in / Sign up

Export Citation Format

Share Document