The study of directional overcurrent relay and directional earth-fault protection application for 33 kV underground cable system in Malaysia (original) (raw)
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TEPES TURKISH JOURNAL OF ELECTRICAL POWER AND ENERGY SYSTEMS, 2021
The intensive use of the underground cables in distribution systems, eventually, results in the total phase-ground capacity of the system to increase. High magnitude of capacitive currents causes capacitive current based sympathetic tripping problem to occur frequently at the distribution system. Directional protection relays may be used to eliminate the sympathetic tripping problem and protect the system selectively. However, it should be known that selective operation of directional relays entirely depends on suitable angle settings. Non-properly angle settings may cause mal operation of directional protection relays. Thus, angle setting of directional protection relays is utilised considering cable cross section area, cable length, parallel feeders number and neutral earthing resistance in this study. The efficiency of the selected angle settings methodology has been confirmed over a field-case distribution system.
The Electrical Power System consists of many vital components. Among them, the Transmission lines are one of the most important parts of the system. Faults occur in transmission lines have high impact on the electrical power system. The major fault in transmission line is single line to ground (L-G) fault, but, various types of faults also occur in transmission line, such as unsymmetrical faults which includes single line to ground (L-G) fault, double line to ground (L-L-G) fault and line to line (L-L) fault and symmetrical faults which are three phase fault. So, the protection relays are needed to protect transmission lines from various types of faults. Overcurrent and earth fault relay is normally used to protect transmission lines, distribution lines, transformers and bus coupler etc. Moreover, these relays can be used as main or backup protection. The modeling of protection relays is required to determine the effects of network parameters and configurations on the operation of these relays. This paper presents the modeling and simulation of standard inverse definite minimum time (IDMT) relay using MATLAB/SIMULINK software. The study of test system is Paunglaung-Pyinmana High Voltage transmission line. The proposed model was tested for single line to ground (L-G) fault and three phase fault witha fault resistance (0.001 Ω)at various locations. The simulation results obtained by MATLAB software show the feasibility analysis of High Voltage Transmission Line with Overcurrent and Earth Fault relay. Keywords-High Voltage Transmission line, Overcurrent and earth fault relay, MATLAB, Single line to ground (L-G) fault, Three Phasefault.
Iraqi journal for electrical and electronic engineering/Al-maǧallaẗ al-ʻirāqiyyaẗ al-handasaẗ al-kahrabāʼiyyaẗ wa-al-ilikttrūniyyaẗ, 2024
The coordination of overcurrent relay protection in the power framework is crucial for preserving electrical distribution systems. It ensures that both primary and backup protection are provided to the system. It is essential to maintain a minimal level of coordination between these relays in order to reduce the overall running time and guarantee that power outages and damage are kept to a minimum under fault conditions. Proper coordination between the primary and backup relays can minimize the operation duration of overcurrent with instantaneous and earth fault relays by selecting the optimum TMS (Time Multiplier Setting) and PS (Plug Setting). The present study investigates the difficulty associated with determining the TMS and PS values of earth-fault and overcurrent relays at the 33/11 kV power distribution substation in Basra using the instantaneous setting element. Overcurrent and earth fault relays were simulated in two scenarios: one with a time delay setting and one with an immediate setting. This procedure was carried out to generate Time Current Characteristics (TCC) curves for each Circuit Breaker (CB) relay took place in the Nathran substation, which has a capacity of 2×31.5 MVA and operates at a voltage level of 33/11 kV. The substation is a part of the Basrah distribution network. The short circuit current is estimated at each circuit breaker (CB), followed by the simulation of protection coordination for the Nathran substation using the DIgSILENT Power Factory software. This research is based on real data collection, and the setting considers the short-circuit current at the farthest point of the longest feeders. The results show the effectiveness of the proposed coordination scheme, which reduced trip operation time by 20% compared to the presented case study while maintaining coordination between primary and backup protection.
Electrical Engineering, 2022
The main goal of this study is to propose new characteristics to an REF 615 model (overcurrent and earth fault relay) that is used for feeder protection in an actual radial system of an Egyptian Substation. When studying fault current, both light and heavy loads as well as fault locations are considered based on the radial nature of the network. The proposed algorithm relies on simultaneously activating the three settings of REF 615 OC relay, with the three settings being set on the respective normal inverse (NI), very inverse (VI) and definite time (DMT) curves. The relay's operating area is divided into two areas. The VI curve functions as a backup for NI in the first area, whereas the NI curve functions as a backup for VI in the second area. The novelty of this study is the proposed model's ability to handle relay failure through its self-protection, which increases the network's protection level and minimizes the relay operating time by about 41.07% for rapid response to a fault. The presence of self-backup protection can minimize the coordination time interval between the main protection and backup protection (CTI) by about 77.98%. The ETAP software is used to investigate the actual radial system and in the analysis of the protection coordination.
gazi university journal of science, 2017
Protection coordination is the heart of all power systems. To insure a quality and reliable operation of the power systems, an electrical fault must be cleared within short time. This can be achieved by proper coordination between the protection relays. In Siddik Kardesler Substation the MV voltage feeders’ protection is provided by overcurrent relays. This paper is principally concerned with practical protection coordination of the electrical substation by using substation as case study. In the Part-2, distance and differential protection will be discussed. Finally, after test and commissioning, the substation is successfully energized without problem.
Protective Relay Coordination in an Injection Substation Using Short Circuit Analysis
International Journal of Advances in Engineering and Management (IJAEM), 2022
This research aims to improve relay coordination in the Port Harcourt Distribution Network using Marine Base 2 X 15MVA, 33/11kV Injection substation as a case study. The method employed is short circuit analysis of the network to determining the sequence of relay coordination to faulton both the existing and enhanced cases, and then applyingElectrical Transient Analyzer Program (ETAP 19.0.1) to model and simulate the network using data gotten from the Port-Harcourt Electricity Distribution Company and the Transmission Company of Nigeria.The result reveals that for the existing case, tripping sequence violation occurred on the 4 (four) primary feeder relays with their respective backup. Churchill feeder fault analysis reveals a total time of operation between the primary relay and its backup for a 3-phase fault as 83.3ms, 213ms, 137ms and 110ms while the order of tripping operation is from feeder breaker, 33kV line breaker, 33kV control panel breaker and 11kV incomer control breaker for the existing case while the improved case, the time of operation is 226ms, 343ms, 411ms and 420ms. This shows the right order of coordination from feeder breaker to 11kV incomer control breaker, 33kV control panel breaker and 33kV line breaker. 3-phase fault on NPA feeder for the existing case, shows the order of time of operation in response to fault as82.9ms, 137ms, 213ms and 110ms. Thus, the sequence is from feeder breaker, 33kV line breaker, 33kV control panel breaker and 11kV incomer control breaker, and improved case is226ms, 343ms, 411ms and 420ms. Fault on Station Road feeder for the existing caseshowsa total time of operation as 84.9ms, 137ms, 213ms and 110ms, whilethe improved case is 240ms, 373ms, 416ms and 420. The total time of operation for a fault on Amadi North feeder for the existing case is 83.6ms, 244ms, 165ms and 110ms while the improved case sequential
Optimal operational characteristics of directional earth fault protection
2017
The function of the directional earth ground fault protection is to protect against ground faults by selecting the output at the substation. Nowadays, ground faults are covered by this function protection, that may have low sensitivity. Given the large number of variables that influence the system, it is necessary to analyze their impact in order to reach an optimal setting. Highly resistive ground faults result in very low residual voltages and currents, but also an angle between them for different ground connections. This results in a drawback in the normal exploration of the MV network. The measuring devices’ errors and their electrical schemes used in the calculation of residual voltage and currents were the subject of study in this work. Moreover, a protection unit was tested in the laboratory to measure the loads of the voltage and current analog inputs. The adopted neutral regime and the variations between its characteristics overhead, underground and mixed lines were analyze...
Directional Earth Fault Protection for Transmission Lines – Need and Operational Experiences
— This paper attempts to bring out the necessity of activating directional earth fault protection in numerical distance relays and also highlights an operational problem with this protection in double circuit lines. These aspects are discussed with specific reference to two incidents taken place in 400 kV and 220 kV transmission lines emanating from Gas Insulated Switchgear (GIS) of 540 MWe Nuclear Power Plant and from 220 kV Out door Switchyard of 220 MWe Nuclear Power Plant respectively.
MATEC Web of Conferences, 2018
The disturbance of the high voltage transmission can be caused by a short circuit, overload, lightning surge, and other natural disturbances. That disturbance can lead to disruption of the distribution of electricity and damage to the electric power system installation equipment. A reliable protection system that can identify the disturbance quickly and also can securing affected parts of the system from other parts that can still operate normally are needed. Protection system operation may fail due to various factors; therefore, in addition to primary protection required backup protection that can work as primary protection fails to work. Distance relays can be used as primary protection as well as remote backup protection on high-voltage transmission. While overcurrent relay (OCR) and ground fault relay (GFR) is used as a local backup if distance relay failed to work. This research conducted a study of protection relays coordination for primary protection or backup protection on t...
Design and Implementation of Overcurrent Relay to Protect the Transmission Line
Power system is prone to faults, because of disoperation of the system or by the natural disasters. This may be caused with damage the components of power system leading to great tasked for their subrogation and cutting the power supply to customers. In this period, much power is exhausted and this stipulation is increasingly transmitted by using transmission line, from one side or place to another side. Different kinds fault may occur in these transmission lines. The major purpose of this article is to analysis and studies the different faults and also declares the impact on transmission line. This work is approach to MATLAB/SIMULINK package. In this work we connect a 100Km terco type and the various cases of fault types are studied where over current relays (OCRs) are used in this work.