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Electrical Aspects
Published in Frank R. Spellman, The Science of Wind Power, 2022
To protect a circuit, a fuse is placed directly into the circuit. A fuse will open the circuit whenever a dangerously large current starts to flow. A fuse will permit currents smaller than the fuse value to flow but will melt and therefore break or open the circuit if a larger current flows. A dangerously large current will flow when a “short circuit” occurs. A short circuit is usually caused by an accidental connection between two points in a circuit that offers very little resistance that passes an abnormal amount of current. A short circuit often occurs because of improper wiring or broken insulation.
Fault Analysis and Protection Systems
Published in Antonio Gómez-Expósito, Antonio J. Conejo, Claudio A. Cañizares, Electric Energy Systems, 2018
José Cidrás, José F. Miñambres, Fernando L. Alvarado
The damaging effects of the faults are numerous and are mainly related to the high currents which can appear in the system. Usually, these current values can be several times the value of the normal operational current and can occasionally produce overvoltage phenomena. The main effects of the faults can be summarized as follows: Conductor heating owing to the Joule effect, which depending on the value and duration of the short circuit can provoke irreversible damage.Electromechanical forces, which can create breakages and sudden conductor displacements possibly resulting in new faults.Voltage variations, which are voltage drops in the failed phases and eventual voltage increases in the others.
Power Flow and Electric Machinery Basics
Published in Pedro Ponce, Arturo Molina, Omar Mata, Luis Ibarra, Brian MacCleery, Power System Fundamentals, 2017
Pedro Ponce, Arturo Molina, Omar Mata, Luis Ibarra, Brian MacCleery
Faults are conditions in which one or more of the phases in a power system are shorted to ground or to each other. Faults also occur if a phase is open circuited. When a short circuit occurs, very large currents flow and these currents can damage the power system unless they are stopped quickly. Unlike overloads, faults must be cleared immediately, so relays are designed to automatically open circuit breakers and isolate faults as soon as they are detected.
Passive Island Detection Method Based on Positive Sequence Components for Grid-Connected Solar–Wind Hybrid Distributed Generation System
Published in Electric Power Components and Systems, 2023
Ch. Rami Reddy, Obbu Chandra Sekhar, B. Pangedaiah, Khalid A. Khan, Muhammad Khalid
4.2.4. Short Circuit Fault. A short circuit fault is another NIS issue in the electrical system. In such circumstances, a recommended method’s performance should be robust to maintain optimal power system performance. A fault condition is simulated by generating a short-circuit fault on a parallel feeder. Consequently, the circuit breaker at the parallel feeder is tripped within 0.02 sec. Accordingly, LLL, L–L, and L–G faults are also simulated. The total fault resistance varies between 1 and 75 for each scenario. The IDI responses to LLL, L–L, and L–G faults are depicted in Figure 11(a). Due to the short settling time of the DS in comparison to the predefined detection delay for all types of defects, no false detection occurred, as indicated in Figure 11(b). The longest time delay necessary for different fault resistances in various faults is shown in Table 2.
Deep learning approaches for fault detection and classifications in the electrical secondary distribution network: Methods comparison and recurrent neural network accuracy comparison
Published in Cogent Engineering, 2020
Daudi Mnyanghwalo, Herald Kundaeli, Ellen Kalinga, Ndyetabura Hamisi
Faults in electric power systems are unpredictable irregular conditions that can be caused by changes in climate conditions, human errors, fire, and electrical hardware failures. Faults in SDN can either be open circuits or short circuits faults. In the distribution networks, short circuits faults occur frequently and can be identified by observing the phase currents (Karić et al., 2017). A short circuit is a type of fault where the electric current passes through an unintended path with very low electrical impedance. Open-circuit faults are the opposite of short circuit faults where there is infinite resistance between two nodes, it is relatively hard to detect open-circuit faults using the current relays (Lau & Ho, 2017). Under ideal states, all phase voltages have the same maximum value but differ in phase from each other at an angle of 120 degrees and deviation of the values by 5% for transmission lines and 10% by distribution lines are considered as the voltage faults.