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.

Ground fault/arc fault circuit interrupter and method of testing the same with a test button and a reset button

Abstract: An arc fault / ground fault circuit interrupter for a power circuit includes a line terminal; a load terminal; and separable contacts electrically connected between the line and load terminals. An operating mechanism opens the separable contacts and has a closed position for closing the separable contacts. A trip mechanism cooperates with the operating mechanism to trip open the separable contacts. A ground fault protection circuit is operatively associated with the power circuit. An arc fault protection circuit is also operatively associated with the power circuit. A circuit tests the ground fault protection circuit, tests the arc fault protection circuit, and restores the operating mechanism to the closed position responsive to sequential activation of test and reset buttons.

Delay-fault diagnosis by critical-path tracing

Abstract: A delay fault diagnosis process consisting of simulation of the fault-free circuit with a four-valued logic algebra and critical-path tracing from primary outputs to primary inputs is presented. An alternative to fault simulation, the method requires no delay-size-based fault models and considers only the fault-free circuit. A sensitivity analysis process for improving diagnosis accuracy is also presented. >

A Novel Single-Phase Adaptive Reclosure Scheme for Transmission Lines With Shunt Reactors

Abstract: Single-phase adaptive reclosure (SPAR) schemes applied to transmission lines have been an effective method to improve the stability of power system. Attractive techniques have been proposed for SPAR schemes based on the tripped fault-phase voltage. But for transmission lines with shunt reactors, the voltage is so minor that the error of voltage transformer limits the applications of voltage-based SPAR schemes. To overcome this disadvantage, a new scheme using differential current between the calculated current based on transient fault model and the actual measured current from the fault phase of shunt reactor is proposed in this paper. The calculated current is obtained by using the transient fault model whether there is a transient or permanent fault. In the case of transient fault, the calculated current is close to the measured current due to the actual fault model being close to the calculated model. As for the permanent fault, the calculated current is quite different from the measured current. Therefore, the differential current of the fault phase can be employed to distinguish permanent fault from transient fault. At last, the Alternative Transients Program simulation results show that the developed algorithm can identify the permanent fault correctly and reliably, and is promised to be applied to SPAR for transmission lines with shunt reactors.

A circuit level fault model for resistive bridges

Abstract: Delay faults are an increasingly important test challenge. Modeling bridge faults as delay faults helps delay tests to detect more bridge faults. Traditional bridge fault models are incomplete because these models only model the logic faults or these models are not efficient to use in delay tests for large circuits. In this article, we propose a physically realistic yet economical resistive bridge fault model to model delay faults as well as logic faults. An accurate yet simple delay calculation method is proposed. We also enumerate all possible fault behaviors and present the relationship between input patterns and output behaviors, which is useful in ATPG. Our fault simulation results show the benefit of at-speed tests.

Combined Fault Detector and Faulted Phase Selector for Transmission Lines Based on Adaptive Cumulative Sum Method

Abstract: In this paper, a novel approach is proposed for fault detection in transmission lines. This idea is based on the adaptive cumulative sum method (ACUSUM), whose structure is adaptive with the current passing through the corresponding line. The proposed ACUSUM algorithm can detect even low magnitude faults with high resistances. By using the proposed method, just a few milliseconds after fault inception, the fault detection unit permits the main protection algorithm to become activated. Moreover, ACUSUM output indices can discriminate faulted phases within only 1 ms after fault registration. This new faulted-phase selector can also be applied to double-circuit transmission lines to detect cross-faults as well as intercircuit faults. The results have shown that the proposed method has good performance in speed and accuracy as a combined fault detector and faulted-phase selector algorithm.