scholarly journals A Novel Methodology to Sense CT Saturation Using Numerical Protection Relays

2020 ◽  
Vol 5 (6) ◽  
Author(s):  
S.S. Raut ◽  
S.S. Hadpe
Keyword(s):  
Power System ◽  
Electronic Device ◽  
Secondary Current ◽  
Protection Relay ◽  
Important Input ◽  
Intelligent Electronic Device ◽  
Protection Devices ◽  
System Designs ◽  
Maximum Reliability ◽  
Primary Current

The necessity for dependability and safety in power system is rising at an alarming rate as the power system designs are getting more & more complex. In order to ensure maximum reliability, the numerical protection relays must receive accurate measurements. One of the most important input measurements desired by the relay is current. Nevertheless, the current measurements expected from current transformers (CTs) can be inaccurate due to occurrence of a phenomenon called as CT saturation. CT saturation causes distortion in the secondary current, which is not linearly proportional to the primary current, leading to mal-operation of protection devices. Therefore it becomes extremely vital that the numerical protection relay, also known as intelligent electronic device (IED) senses the CT saturation condition and blocks its operation so as to avoid mal-operation of the IED which may lead to supply interruption, further resulting in production losses and undesirable switching of the sensitive equipments affecting system reliability and customer satisfaction. This paper includes a review of the background about CTs & proposes a novel methodology to exclusively sense the CT saturation using the numerical protection relays reliably and cost effectively.

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.

Laboratory Test of Current Transformer Operates under Harmonic Conditions

2015 ◽  
Vol 793 ◽  
pp. 222-225
Author(s):  
Indra Nisja ◽  
A.Z. Abdullah ◽  
S. Masri ◽  
S. Hardi
Keyword(s):  
Power System ◽  
Laboratory Test ◽  
Harmonic Distortion ◽  
Current Transformer ◽  
Total Harmonic Distortion ◽  
Current Harmonics ◽  
Secondary Current ◽  
Primary Current

This research focused on the effect of harmonic to the performance of current transformer (CT) operates under harmonic conditions. Due to the increasing of harmonic in power system, the CT did not perform well. The CT may saturates due to the presence of voltage and current harmonics. In this project, a laboratory test was conducted to investigate and analyze the influence of harmonics to the CT performance. This CT has been test with different Total Harmonic Distortion Current (THDi) at primary side and constant primary current. The experiment result shows the secondary current CT errors will increases when THDi increases.

Research on Electrical Power System with Information Modeling and SCL Description of IED for Transformer Condition Monitoring Based on IEC61850

2013 ◽  
Vol 676 ◽  
pp. 177-180
Author(s):  
Yun Tao Sun ◽  
Xin Jian Tang ◽  
Jue Long Li ◽  
Xiu Chen Jiang
Keyword(s):  
Power System ◽  
Condition Monitoring ◽  
Electronic Device ◽  
Electrical Power ◽  
Information Modeling ◽  
Insulation Material ◽  
Electrical Power System ◽  
Description Language ◽  
Reporting Service ◽  
Intelligent Electronic Device

A transformer is a critical device in an electrical power system substation. Monitoring its condition, including insulation material statuses, is imperative. This article discusses the information modeling techniques of IEC61850 and modeling steps of condition-monitoring IED, analyzes the reporting service, focuses on the characteristics of transformer condition monitoring, rationally develops and makes use of logical nodes and data in the IEC61850 standard, conducts modeling for the actual intelligent electronic device (IED) of transformer condition monitoring and describes the model with substation configuration description language (SCL). The configuration file of this model has passed the test done with standard syntax (Schema mode).

scholarly journals Bi-Directional Power Flow in Switchgear with Static Transfer Switch Applied at Various Renewable Energies

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3187
Author(s):  
Keon-Woo Park ◽  
Chul-Hwan Kim
Keyword(s):  
Communication System ◽  
Power Flow ◽  
Electronic Device ◽  
Test Sequence ◽  
Test Results ◽  
Distributed Generations ◽  
Prototype Development ◽  
Intelligent Electronic Device ◽  
Bidirectional Power Flow ◽  
Actual Test

In this study, we describe the development of a plug-in type of switchgear that can control bidirectional power flow. This switchgear system can connect distributed generations such as photovoltaic and wind turbine generation, and AC and DC loads. The proposed switchgear system consists of an inverter for connecting distributed generations and DC load, a static transfer switch (STS) that can control and interrupt the bidirectional power flow, and an intelligent electronic device (IED) that can control each facility using a communication system. Since the topology inside the switchgear is composed of DC bus, it can be operated as a plug-in type of system that can be used by simply connecting the converters of various distributed generations to the inverter in the developed switchgear system. In this study, we describe the overall structure of the proposed switchgear system and the operation of the components. In addition, prototypes of each facility are developed and the results of building a small testbed are presented. Finally, we verify the operation of the inverter by performing an experiment on the testbed and show that throughout a test sequence the proposed switchgear system works normally. The contributions of this study are the development of a plug-in type of switchgear for AC/DC and the actual test results presented through prototype development and testbed configuration.

scholarly journals The design of electric drives with electronic protection devices

2018 ◽  
Vol 226 ◽  
pp. 04012
Author(s):  
Boris D. Khastsaev ◽  
Larisa M. Dedegkaeva ◽  
Maksim P. Maslakov
Keyword(s):  
Physical Quantity ◽  
Linear Dependence ◽  
Electronic Device ◽  
Measuring Circuit ◽  
Structural Scheme ◽  
Electric Drives ◽  
Intelligent Sensors ◽  
Protection Devices ◽  
Physical Quantities ◽  
Improved Characteristics

The possibility of designing an electronic device for protection and diagnostics of electric drives with improved characteristics is considered. The technique and algorithm of design of similar devices, the structural scheme of the device constructed on their basis are offered. To improve the characteristics of the device of protection and diagnostics of electric drives in the work it is proposed to provide for the use of measuring transducers with linear dependencies of the output values on the controlled ones. The latter is possible as a result of the use of measuring circuits in measuring transducers with linearized dependencies of the output values on the input and the use of intelligent sensors. As a measuring circuit for the construction of measuring transducers is considered the measuring circuit of Kenigsberg, which is characterized by a linear dependence of the output active value of the passive measured (controlled physical quantities). At the same time, the intelligent sensors are additionally assigned the function of linearization of the output dependence of a «simple» sensor on the controlled physical quantity.

Critical Clearing Time Associate with Relation of Power Load Factor and Frequency in Transient Stability

2015 ◽  
Vol 743 ◽  
pp. 257-262
Author(s):  
Ming Jong Lin
Keyword(s):  
Power System ◽  
Power Factor ◽  
Transient Stability ◽  
Automatic Monitoring ◽  
Load Factor ◽  
Protection Relay ◽  
Power Load ◽  
Clearing Time ◽  
The One ◽  
Time Point

Critical clearing time is to determine the time point of the collapse of the power system when the power system occur transient stability by a huge of failure. So that the one is an important data on protection system in power system. Therefore as an electrical engineer must to look on mostly the point of one to analyze and design in the power. In this paper, through the protection relay and breaker analysis of operation to know the team of protection relay how to complete the automatic monitoring and isolated the fault-equipment in power system. To study and analyze the swing equation and equal area criterion, we found out the relation of critical clearing time is changed with power factor and frequency. The critical clearing time was verified a non-constant value which is changed with the power factor and; if the load power factor is high, the critical clearing time is high but the frequency is high, the critical clearing time is low with system swing in the transient stability. This paper will be verify below each paragraph.

Design for Robot Control Board Based on AVR Single Chip Microcomputer

2014 ◽  
Vol 484-485 ◽  
pp. 570-573 ◽  
Author(s):  
Hong Li ◽  
Si Qing Zhang
Keyword(s):  
Robot Control ◽  
Electronic Device ◽  
Rapid Development ◽  
Decisive Role ◽  
Control Board ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Electronic Products ◽  
Intelligent Electronic Device ◽  
Avr Mcu

Application of single chip microcomputer in the ubiquitous in modern life, as electronic products, intelligent upgrade, MCU control board play a decisive role, the design of main control board system for intelligent electronic device provides a more rapid development. This paper firstly introduces the properties of AVR single chip, the performance of AVR MCU design the control board of the corresponding circuit, and to study its programming method, is convenient for the users to operate, it is applied to the hardware.

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