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.

Design of Smart MVDC Power Grid Protection

Abstract: Improved reliability and safety of the medium-voltage dc power distribution systems on board of all electric ships are the objectives of this paper. The authors propose the integration of the self-healing capability against faults of the measurement system in power system fault detection and protection systems. While most of previous work in the literature focuses on either one aspect independently, here, the two are integrated. On one hand, our approach addresses also the case of concurrent power system fault and measurement system fault. On the other hand, the proposed approach must be capable of distinguishing between the two types of failure. The proposed architecture is based on exchange of information between energy conversion and measurement devices. This makes the impact of communication delays critical, so its analysis is provided for the proposed case study. The impact on the performance of the measurement validation and protection systems is derived and can provide hints on the design. The protection method used as case study consists in controlling power converters to ride through the power system fault while maintaining power supply to the vital loads. To overcome failures of the measurement system, invalid data were detected and reconstructed through their expected value.

Unsynchronised fault-location technique for three-terminal lines

Abstract: This study describes a new fault-location technique using negative-sequence voltage for three-terminal lines. The ratios between the negative-sequence voltage magnitudes measured at each terminal are utilised to first determine the faulted section and then to estimate the exact fault location within the section. Since the current data is not deployed, the influence of inherent errors of current transformers can be avoided. The proposed method can accurately locate the unbalanced faults, that is, single-phase-to-ground, double-phase-to-ground, and phase-to-phase faults, regardless of the fault resistance and pre-fault conditions and without any need to identify the fault type. The method requires only the negative-sequence reactance behind each terminal which can be estimated by the short-circuit analysis with an acceptable accuracy. Reliability and practicality of the proposed method make it an attractive option to include in numerical protective relays. Simulation experiments with different fault cases reveal the capability of the proposed method.

Systems and methods for determining location of a fault on an electric utility power distribution system

Abstract: A power line fault locating system employing combinations of conducted electrical transient signals recorded at specific points in the power delivery network, radiated electromagnetic signals produced by the air-gap arc preceeding the fault current or by the lightning discharge causing the fault, and knowledge of the power line path associated therewith. The arrival time of conducted transient signals produced by the fault are detected with microsecond accuracy through use of a fault recording sensor (FRS). The low level electromagnetic radiation (VHF/UHF) caused by arcing associated with power line faults is detected at at least one arc detection sensor (ADS) located at some distance from the power line. The ADS senses the time of arrival of the radiated signal associated with the fault. These two sensors for detecting the conducted and radiated signals are coupled to a central power line fault locating analyzer (PLFLA) that receives and manipulates the information using appropriate algorithms and databanks containing geographical maps of electric utility power systems, to arrive at the power line fault location. In an alternative system embodiment, multiple ADS units located about a power distribution network determine the time of arrival of arcing information which is communicated to the PLFLA to determine the power line fault location. In a related system, the precise time of occurrence of a lightning discharge associated with a lightning-caused power line fault is combined with the arrival time of conducted signals from at least one FRS and communicated to a PLFLA.

Open-Phase Fault Detection of a Five-Phase Permanent Magnet Assisted Synchronous Reluctance Motor Based on Symmetrical Components Theory

Abstract: This paper presents a novel approach for open-phase fault detection of a five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM). Under faults, the five-phase PMa-SynRM is expected to run at fault-tolerant control (FTC) mode, otherwise it draws a large amount of current with a significant reduction in the reluctance torque. To successfully achieve FTC operation of five-phase PMa-SynRM, the accurate detection of a fault condition has to be preceded. With the best of these authors knowledge, the detection of faults has been limitedly studied for five-phase motors. The analysis of open-phase fault in five-phase machine involves complicated conditions including single-phase open fault, two-phase adjacent fault, and two-phase nonadjacent fault. To perform the timely fault-tolerant operation, those faults have to be accurately analyzed and detected. In this paper, a novel symmetrical components (SCs) analysis is utilized to extract the feature of those fault conditions. This analysis will provide the types of faults by logically analyzing the pattern of magnitude and phase angle changes of the fundamental signal in the SCs. The proposed method has been comprehensively analyzed through theoretical derivation, finite-element simulations, and experimental testing through a 5 hp PMa-SynRM controlled by TI-DSP F28335.