scholarly journals Prevention of Cascaded Events of Distance Relay Zone Three Using Logic Controls

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohamed Younes E. Henna ◽  
Sayed A. Nagy
Keyword(s):  
Transmission Line ◽  
New Method ◽  
Defense System ◽  
Distance Relay ◽  
System Parameters ◽  
Critical Situation ◽  
Cascaded Events ◽  
Distance Relays ◽  
Line Overload

This paper presents a new method to prevent cascaded events caused by zone 3 elements of distance relays due to transmission line overload by using logic controls. A proposed adaptive distance relay algorithm provides a new concept to distinguish between actual faults and flow transfers and secures time to perform remedial controls by a defense system during cascaded events. Maloperation of distance relay is a very critical situation, leading to more operation of other distance relays and finally partial or total blackout. Logic controls are used to insure the operating decision through observing the system parameters and compare it with a setting already being input to the system. When distance relay is activated and the logic controls find that the system is healthy (unfaulted) and that the activation resulted from transmission line overload not real fault, the operation signal will be blocked to protect the system from maloperation.

Visualising the Response of Distance Relays in the Series Compensated Transmission System - Understanding the Problems and some Practical Solutions.

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Abhishek Khanna
Keyword(s):  
Transmission Line ◽  
Transmission System ◽  
Distance Relay ◽  
Series Compensation ◽  
Novel Methods ◽  
Distance Relays ◽  
Direction Determining

This paper discusses problems and the possible solutions for protecting series compensated transmission line with distance relays. The paper also takes into consideration the influence of the series compensation on the distance relays installed on the short lines adjacent to the compensated line. Starting from visualising the response of the distance relays, the paper proposes some simple but novel methods to secure and improve the distance relay response. The methods include new impedance and direction determining techniques, placement of CVT and setting considerations. The material presented in this paper is based on the authors experience in protecting series compensated lines with distance relays.

scholarly journals Modelling and Simulation of Mho Type Distance Relay for High Voltage Transmission Line Protection Using MATLAB Software

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Win Win Tun ◽  
Ohn Zin Lin ◽  
Han Su Yin
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Modelling And Simulation ◽  
Fault Line ◽  
Distance Relay ◽  
Double Line ◽  
Ground Fault ◽  
Three Phase ◽  
Distance Relays ◽  
Transmission Line Protection

Transmission lines are an important part of a power system. Transmission lines have high power transmission capacity and they are prone to faults of larger magnitudes. Various faults occur in transmission lines. Therefore, protection relays are necessary to protect transmission lines. The purpose of protection system is to interrupt the faulty section from the healthy section because the fault currents may damage the electrical equipments. One of the protection relays is distance relay and it is mainly used in transmission line. Sometimes these relay are used for backup protection. Distance relays for determining the impedance need the voltage and current. Transmission lines are typically protected by distance protection relay. Distance relays are considered of high speed class and can provide transmission lines. Nowadays, numerical distance relays have been used instead of using electromechanical and static distance relays. The proposed model was verified under different tests such as single line to ground (L-G) fault, double line to ground (L-L-G) fault, line to line (L-L) fault and three phase (L-L-L) fault. SimPower System was used for modelling and simulation of distance relay, transmission lines and faults. The simulation results were obtained from MATLAB software shows the feasibility of analysis of transmission line protection with mho type distance relay for single line to ground fault, double line to ground fault, line to line fault and three phase fault at different location of transmission lines. The difficulties understanding on operation of distance relay can be cleared by using MATLAB/SIMULINK software.  

scholarly journals Distance Relay Protection Improvement of Alaoji-Afam 330kV Transmission Line

2018 ◽  
Vol 3 (9) ◽  
pp. 40
Author(s):  
Eseosa Omorogiuwa ◽  
Wonodi Ikonwa
Keyword(s):  
Transmission Line ◽  
Impedance Measurement ◽  
Relay Protection ◽  
Distance Relay ◽  
Fault Resistance ◽  
Good Improvement ◽  
Distance Relays ◽  
Protected Zone

Fault resistance influences the operation of distance relays, thus causing it to give inaccurate impedance measurement, thus resulting to under-reach condition. .Trip report of fault occurrence in Alaoji-Afam 330kV line showed the effect of fault resistance on the relay operation. This paper seek to improve distance relay performance in terms of reliability, speed and selectivity on Alaoji-Afam 330kV transmission line, when fault resistance is present through adjustment of protected zone reach using NEPLAN software to model and simulate distance relay used for this study. Several simulations were run and the results showed good improvement of distance relay operation in handling fault conditions. Adjustment of the protected zone reach was done to compensate for the effect of high fault resistance on distance relay operation.

Differential Equation Based Adaptive Distance Relaying Setting Method for Series Compensated Line

2014 ◽  
Vol 1044-1045 ◽  
pp. 482-485
Author(s):  
Jin Hu Zhang ◽  
Zhen Yu Xu ◽  
Zhi Peng Su
Keyword(s):  
Differential Equation ◽  
Transmission Lines ◽  
Distance Relay ◽  
Iterative Calculation ◽  
Simple Simulation ◽  
Simulation Results ◽  
Distance Relays ◽  
Distance Relaying

The distance relays of transmission lines find limitations in the presence of series compensated capacitor. One of them is the distance relay setting issue, in which either over-reach problem or under-reach problem may occur. To deal with this issue, a differential equation based adaptive distance relaying setting method for series compensated line is proposed. As for it do not need to identify whether SC/MOV is in fault loop, not need to know the parameters and the operating states of SC/MOV/GAP, and furthermore, it can be realized without the iterative calculation, it is very suitable to be used for the distance relaying adaptive setting of series compensated line. Simple simulation results certificate the proposed adaptive setting method.

scholarly journals Suggestion of a New Protection Scheme for a Transmission System Equipped with a Thyristor-Controlled Series Capacitor

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2250
Author(s):  
Minh-Chau Dinh ◽  
Minh-Quan Tran ◽  
Jae-In Lee ◽  
Seok-Ju Lee ◽  
Chur Hee Lee ◽  
...  
Keyword(s):  
Transmission Line ◽  
Power Flow ◽  
Operation Mode ◽  
System Stability ◽  
Test Bed ◽  
Distance Relay ◽  
Protection Scheme ◽  
Thyristor Controlled Series Capacitor ◽  
Real Time Digital Simulator ◽  
Series Capacitor

A thyristor-controlled series capacitor (TCSC) is employed to a transmission line in order to enhance the usable capacity of the present as well as upgraded lines, improve system stability, reduce losses, and improve power flow control capability. However, in an abnormal situation, the TCSC may transit from the existing operation mode to the other mode according to its control system and protection strategy. There is much difference in the impedance of the TCSC between each mode. This threatens the reliability of the conventional protection system, especially the distance relay, that works based on the measurement of line impedance. In this paper, we suggest a new protection scheme for a distance relay of a transmission line equipped with a TCSC. In the suggested method, in order to mitigate the effect of the TCSC in the fault loop, the TCSC injected voltage is subtracted from the measured phase voltage before supplying the voltage signal to the distance relay. The suggested scheme was verified by a real time digital simulator (RTDS)-based closed-loop test bed of a protective relay. The effect of the TCSC in the fault loop was completely mitigated. The distance relay works properly with the suggested scheme.

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