Fault indicator

About: Fault indicator is a research topic. Over the lifetime, 10057 publications have been published within this topic receiving 143482 citations. The topic is also known as: FCI & power line fault indicator.

Fault sensor suitable for use in heterogenous power distribution systems

Abstract: A fault sensor suitable for use in a heterogenous power distribution system executes a stored program and causes sufficient information to be collected to distinguish a source of fault current as being from a public utility portion of the power distribution network or from a distributed generator. Short circuit current and magnetizing current are reliably distinguished based on differences in VI "signatures." In addition, the fault sensor periodically senses a condition of a battery of the fault sensor. When the condition of the battery indicates the battery power is low, the fault sensor sends a digital data signal including a low battery indication to a remote location. Subsequent to occurrence of a sustained power outage, the sensor detects that power has been restored and sends to a remote location a digital data signal including an indication that power has been restored. The sensor periodically measures peak line voltage and peak line current and reports peak values to the remote location.

DC–AC Converter-Fed Induction Motor Drive With Fault-Tolerant Capability Under Open- and Short-Circuit Switch Failures

Abstract: In this paper, a new fault tolerant dc–ac converter-fed induction motor drive is proposed to maintain motor as close as possible to its desired normal operation under open- and short-circuit switch failures. The operational principles for fault detection and isolation schemes are provided. Two control strategies including predictive control and voltage mode-controlled PWM with integral-double-lead controller for two stage of the converter are presented in conjunction with the elaborated discussion. The control strategy determines appropriate switching states for continuous operation of the drive after a fault. The proposed topology makes it possible to integrate the minimal redundant hardware and full tolerance capability which is an important advantage of the proposed topology. Moreover, the most important advantages of the proposed topology are a fast response in a fault condition and low cost of the converter in comparison with the evaluated topologies. A Joule-integral-based method for selecting an appropriate rating of applied fuses has been presented to provide a reliable fault-isolation operation. Also, a comparison with currently available fault-tolerant dc–ac converters is given to show the merits of the proposed topology. Finally, the experimental results are presented to verify the validity of the theoretical analysis and industrial feasibility of the proposed converter.

Effects of the fault inception angle in fault-induced transients

Abstract: The analysis of fault-induced transients in three-phase overhead transmission lines can provide extensive information about the fault type, detection, location, direction and sustained time in satisfactory agreement with real application in protective relays These transients depend on the system topology, load condition and the fault parameters, such as the fault type, resistance, inception angle and location This study addresses the fault inception angle effects in the energies of the fault-induced transients in both voltages and currents by means of the wavelet coefficient energy analysis at the first three wavelet scales, in which a generic energy equation regarding the fault-induced transients as a function of the fault inception angle in all kinds of faults was established

Simulation of internal faults in synchronous generators

Abstract: An internal fault in the armature winding of a synchronous generator occurs due to the breakdown of the winding insulation. In this paper, a method for simulating internal faults in synchronous generators, using direct phase quantities, is described. Simulation results showing the fault currents, during a single phase to ground fault and a two phase to ground fault, are presented.

Harmonic Order Tracking Analysis: A Novel Method for Fault Diagnosis in Induction Machines

Abstract: The diagnosis of induction machines using Fourier transform relies on tracking the frequency signature of each type of fault in the current's spectrum, but this signature depends on the machine's slip and the supply frequency, so it must be recomputed for each working condition by trained personnel or by diagnostic software. Besides, sampling the current at high rates during long times is needed to achieve a good spectral resolution, which requires large memory space to store and process the current spectra. In this paper, a novel approach is proposed to solve both problems. It is based on the fact that each type of fault generates a series of harmonics in the current's spectrum, whose frequencies are multiples of a characteristic main fault frequency. The tracking analysis of the fault components using the harmonic order (defined as the frequency in per unit of the main fault frequency) as independent variable instead of the frequency generates a unique fault signature, which is the same for any working condition. Besides, this signature can be concentrated in just a very small set of values, the amplitudes of the components with integer harmonic order. This new approach is introduced theoretically and validated experimentally.