Compensation of nonlinearities in a current transformer for the reconstruction of the primary current

2001 ◽  
Vol 9 (4) ◽  
pp. 565-573 ◽  
Author(s):  
S. Bittanti ◽  
F.A. Cuzzola ◽  
F. Lorito ◽  
G. Poncia
Keyword(s):  
Current Transformer ◽  
Primary Current ◽  
A Current

Analiza algoritama za kompenzaciju zasićenja strujnog transformatora

2020 ◽  
Vol 22 (1-2) ◽  
pp. 112-118
Author(s):  
Nenad Belčević ◽  
◽  
Zoran Stojanović
Keyword(s):  
Relay Protection ◽  
Current Transformer ◽  
Main Function ◽  
Negative Consequences ◽  
Current Transformers ◽  
Secondary Current ◽  
Measuring Devices ◽  
Protection Devices ◽  
Primary Current ◽  
A Current

The main function of current transformers is to adapt the high values of the primary current to values suitable for the operation of relay protection devices, i.e. measuring devices. Under normal conditions, a current transformer transforms the current in a virtually permanent ratio, and practically without a phase shift, so the secondary current is actually a scaled value of the primary current. However, when a fault occurs in the power system, currents reach high values. As a result, the flux in the core of the current transformer can reach values above the knee of the magnetization characteristic, causing saturation of the current transformer. When saturation occurs, the secondary current is no longer a scaled value of the primary current, but is deformed. Deformation of the secondary current may cause malfunctioning of some relay protection devices. The development of digital relay protection has made it possible to perform software saturation compensation by applying certain algorithms, thus eliminating the negative consequences that saturation of the current transformer causes. In this paper, one of the possible approaches for compensation of saturation is analyzed, which is based on the application of an equivalent scheme and magnetization curve of the current transformer. Two typical approaches have been singled out, which have been analyzed and tested in more detail. Testing was performed in the MATLAB/Simulink.

scholarly journals A simplified model of a current transformer for studying relay protection operation in transient conditions

2021 ◽  
Vol 25 (4) ◽  
pp. 450-462
Author(s):  
T. S. Mukhametgaleeva ◽  
D. S. Fedosov
Keyword(s):  
Current Transformer ◽  
Voltage Characteristic ◽  
Simplified Model ◽  
Current Voltage Characteristic ◽  
Current Transformers ◽  
Transient Conditions ◽  
Transformation Ratio ◽  
Current Voltage ◽  
Primary Current ◽  
A Current

We develop a simplified model of a current transformer based on its current-voltage characteristic. This model is applicable for studying relay protection operation in transient conditions when no high accuracy or consideration of current transformer magnet core hysteresis is required. The model was developed in MATLAB Simulink using elements of the SimPowerSystems and Simscape libraries. The model uses the transformation ratio and current-voltage characteristic obtained during operational tests of a current transformer. Calculation experiments with non-linear resistance found that a currentvoltage characteristic of voltage and current values can be used to model a current transformer, rather than instantaneous values. The following conditions were simulated: for nominal currents in current transformer windings to check the transformation ratio; for opened secondary winding; with current transformer saturation by increasing secondary loading; increasing the primary current ratio and presence of aperiodic current at the start of the transition process. It was found that the developed current transformer model allows for a correct imitation of all the above conditions. To verify the model, secondary current oscillograms were obtained using real current transformers 10 kV at known primary current, which were compared with nominal oscillograms in the model. The discrepancy between the results of calculational and real experiments was no more than 10% in amplitude values, with high-quality matching obtained for current charts in the model and real current transformers. A significant advantage of the developed model is that its setting requires no information on magnet core cross-section, power line length, steel grade, and the number of current transformer winding turns.

In-situ measurement of the current transformer burden in a current transformer testing system using a shunt resistor

Measurement ◽  
2007 ◽  
Vol 40 (9-10) ◽  
pp. 876-882 ◽  
Author(s):  
Jae Kap Jung ◽  
Jeon Hong Kang ◽  
Sang Hwa Lee ◽  
Myungsoo Kim
Keyword(s):  
Current Transformer ◽  
In Situ Measurement ◽  
Testing System ◽  
A Current

Electricity Usage Monitoring Based On Internet of Things

2021 ◽  
Vol 20 (3) ◽  
pp. 37-42
Author(s):  
Mohd Ridzuan Ahmad ◽  
Hishamuddin Hashim
Keyword(s):  
Internet Of Things ◽  
Electricity Consumption ◽  
Current Transformer ◽  
Consumption Pattern ◽  
Process Scheduling ◽  
Time Data ◽  
Domestic Use ◽  
Electrical Consumption ◽  
The Internet Of Things ◽  
A Current

Electricity monitoring systems have long been used in industrial scenarios such as process scheduling and distribution. This monitoring system needs to be developed for domestic use such as in homes and shops. In recent times, the electricity demand has increased in households with the use of different appliances. The advent of technologies such as the Internet of Things (IoT) has made real-time data acquisition and analysis possible. This project is designed to control and monitor household electricity consumption via smartphones using the ESP8266 Wi-Fi module as a communication protocol and the Blynk application as a private server. The used wifi module provides notification through the Blynk application. The system uses an Arduino Mega2560 microcontroller to control all devices in this project. For monitoring the energy usage, a current sensor type Split Core Current Transformer (SCT013) was used. From the experimental results, it is confirmed that the system is capable of monitoring the whole house’s electrical usage easily. With this system in place, end-users are provided with proper awareness and able to plan their home’s electrical consumption pattern effectively.

Busbar differential protection in conjunction with a current transformer compensating algorithm

2008 ◽  
Vol 2 (1) ◽  
pp. 100 ◽  
Author(s):  
Y.C. Kang ◽  
J.S. Yun ◽  
B.E. Lee ◽  
S.H. Kang ◽  
S.I. Jang ◽  
...  
Keyword(s):  
Current Transformer ◽  
Differential Protection ◽  
A Current

Using a Current Loop and Homogeneous Primary Winding for Calibrating a Current Transformer

2013 ◽  
Vol 62 (6) ◽  
pp. 1658-1663 ◽  
Author(s):  
Karel Draxler ◽  
Renata Styblikova ◽  
Vlastimil Rada ◽  
Jan Kucera ◽  
Martin Odehnal
Keyword(s):  
Current Transformer ◽  
Current Loop ◽  
A Current
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