scholarly journals An accurate technique for supervising distance relays during power swing

2021 ◽  
Vol 21 (3) ◽  
pp. 1279
Author(s):  
Loai Mohamed Ali El-Sayed ◽  
Doaa Khalil Ibrahim ◽  
Mahmoud Ibrahim Gilany ◽  
Aboul’Fotouh El’Gharably
Keyword(s):  
Power System ◽  
The State ◽  
Distance Relay ◽  
Transient Phenomenon ◽  
Power Swing ◽  
Switching Line ◽  
Power Frequency ◽  
Simulation Results ◽  
Distance Relays ◽  
Line Switching

Power swing is a power system transient phenomenon that arises due to several reasons including line switching, line outage, sudden increment or decrement in load, faults, etc. Unnecessary tripping during power swing and unnecessary blocking for faults occur during power swing result in distance relay maloperation. Several cascaded outages and major worldwide blackouts have occurred due to maloperation of distance relays. This paper proposes a technique for supervising distance relays during power swing. The proposed online technique discriminates real faults and power swing accurately. It relies on constructing a locus diagram for the current and voltage differences (∆I-∆V) between the two ends of the protected line. The locus is estimated at every power frequency cycle to continuously monitor the state of the line by utilizing the synchrophasor measurements at the sending and receiving ends of the line. The proposed technique is tested for two-area, four-machine power system under faults at different locations of zone-1 and zone-2 regions of distance relays, fault resistances, fault inception angles and slip frequencies using MATLAB software. The simulation results proved the superior improvement of distance relay performance for handling power swing blocking and unblocking actions.

An Enhanced Symmetrical Fault Detection during Power Swing/Angular Instability using Park’s Transformation

2016 ◽  
Vol 2 (1) ◽  
pp. 23 ◽  
Author(s):  
Jeevitha A ◽  
Devi S
Keyword(s):  
Fourier Transform ◽  
Power Systems ◽  
Operating Conditions ◽  
Electrical Machine ◽  
Distance Relay ◽  
Power Swing ◽  
Three Phase ◽  
Wide Range ◽  
Simulation Results ◽  
Line Switching

<p>Power systems are subjected to a wide range of small or large disturbances during operating conditions. Power system disturbances such as line switching, generator disconnection and sudden removal of faults causes oscillations in an electrical machine rotor angles that can result in severe power swings. Depending on the protection controls, the system may remain stable or unstable and it may result in loss of synchronism. In recent years, distance relay finds difficulty between symmetrical fault and power swing which causes undesired tripping of the transmission line is the foremost reason for blackout. This paper proposes a new method Park’s Transformation and Fast Fourier Transform which are used to discriminate between the three phase fault and power swing and also to protect the backup zone of distance relay. This method is verified for normal and abnormal conditions with different load angles and different fault locations in IEEE 6-bus system are simulated in MATLAB/ Simulink. The Simulation results show the capability to avoid unwanted tripping decision of relay quickly and precisely.</p>

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.

Detection of symmetrical fault and discrimination from power swing using MOPSVC approach

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kumarraja Andanapalli ◽  
Monalisa Biswal
Keyword(s):  
Power System ◽  
Positive Sequence ◽  
Distance Relay ◽  
Security Issues ◽  
Power Swing ◽  
Three Phase ◽  
Sequence Components ◽  
Zero Sequence ◽  
Simulation Task ◽  
Eastern Regional

Abstract Distance relay are designed with swing blocking/tripping logic to maintain reliable and secure operation of power system. To prevent this from happening, the relay is functioned with a power swing blocking (PSB) logic. However, ensuring proper detection to swing event requires to overcome from the dependable situation such as three-phase fault. The relay refuses to behave normally if both swing and three-phase fault occur simultaneously. Reliable setting is essential to generate trip/block command. Unsymmetrical faults are easily detected during the swing condition due to the presence of negative and zero sequence components, but such components are absent in the case of symmetrical/three-phase fault. As a result, symmetrical fault under blocking condition is unidentified many a times by the distance relay, arising security issues. To improve the relay operation during swing and symmetrical fault conditions, a MOPSVC (multiplication of positive sequence voltage and current) based index is developed in this work. The MOPSVC index helps to discern power swing from three-phase fault. To test the efficacy of the method, a 230 kV, 50 Hz two-area four machine system, and Indian Eastern Regional Grid (IERG) network are considered. Simulation task is conducted using EMTDC/PSCAD software. To investigate the performance of the proposed method, various swing phenomena, faults, CT saturation, switching transients, and the presence of noise cases are considered, and the results demonstrate the robustness of the proposed algorithm. Responses under stressed power system conditions are also investigated, and a report on comparisons with existing methods is provided. Simulated results confirm that the proposed algorithm can balance the dependability and security aspects of the protection logic.

Adaptive Distance Protection to Prevent False Relay Tripping during Power Swing

2015 ◽  
Vol 785 ◽  
pp. 358-362
Author(s):  
Nor Zulaily Mohamad ◽  
Ahmad Farid Abidin ◽  
Ismail Musirin
Keyword(s):  
Power System ◽  
Distance Protection ◽  
Distance Relay ◽  
Power Swing ◽  
Adaptive Protection ◽  
Short Circuits

The existing distance relay is accommodated with starting function to detect short-circuits in power system. However, this function proves vulnerable to distance relay operation as it could falsely send a tripping signal during power swing. Hence, it is important to introduce an adaptive concept to the distance protection to prevent such false tripping. This paper presents a simple and effective adaptive protection algorithm for power swing prevention based on Under Impedance Fault Detector (UIFD) characteristics, in which capable to identify the power swing condition and adjusting the relay setting accordingly to avoid system mal-operation.

Fault Location Algorithm of the 10kV Rural Network Based on Power Frequency Communication

2013 ◽  
Vol 722 ◽  
pp. 287-291
Author(s):  
Shan Su ◽  
Bing Sheng Yan
Keyword(s):  
Power System ◽  
Fault Location ◽  
Low Cost ◽  
Basic Theory ◽  
Distributed Network ◽  
Original Sequence ◽  
Fault Locating ◽  
Power Frequency ◽  
Location Algorithm ◽  
Simulation Results

A new fault locating model of multi-ports data of 10kV village distributed network has been constructed abased on the basic theory of liner circurt. by taking fault ports as boundaries, the faulted power system is divided into a symmetrical network without the faults and unsymmetrical networks employed to simulate the faults. In this modell, The locating of fault point is looked as an unknowed variable and it is included in the Zbus of unsymmetrical network. We can get it though solving the equation. The method does not need to modify the Zbus of original sequence network and easy implementation on computer, Using TWACS transmits the multiport data information, low cost and can achieve collapse go traffic. The simulation results of Matlab proved that the algorithm is effective.

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