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Electric vehicles (EVs) require uninterrupted and safe conditions during operations. Therefore, the diagnostic of power devices and electric motor faults are needed to improve the availability of the system. Hence, fault-tolerant control (FTC), which combines switch fault detection, hardware redundancy and post-fault control, is used. This paper aims to propose an accurate open-phase fault detection and FTC of a direct torque control permanent magnet synchronous motor electrical vehicles by using discrete Fourier-transform phase method.

The main idea is to propose detection and identification of open-phase fault (faulty leg) among three phases voltage source invertor (VSI)-fed permanent magnet synchronous motor drives. Once the faulty leg is detected and isolated, a redundant phase leg insertion, shared by a three-phase VSI, is done by using independent bidirectional TRIAC switches to conduct FTC system. This accurate fault detection significantly improves system availability and reliability. The proposed method of open-phase fault detection and identification is based only on stator phase current measurement.

A novel method is proposed with experimental validation for fault detection, isolation and FTC for a three-phase VSI-fed permanent magnet synchronous motor.

The novel discrete Fourier-transform phase method is proposed to detect an open phase based on the measurement in real time of the instantaneous phase of stator current components in the stationary frame. The experimental implementation is carried out on powerful dSpace DS1104 controller board based on the digital signal processor TMS320F240. The validity of the proposed method has been experimentally verified.

This paper aims to reproduce the electrical connector intermittent fault behaviours with step-up vibration stress while maintaining the integrity of the product.

A dynamic model of an electrical connector under vibration is established for contact resistance analysis. Next, the dynamic characteristics of contact resistance are analysed, and cumulative damage theory is used to calculate the damage under different stresses during the intermittent fault reproduction test. To reduce damage and improve efficiency, the step-up stress is used for the reproduction test.

The proposed method can reproduce the intermittent fault behaviour, and the step-up stress test is more efficient than the constant stress test.

Step-up stress is used for intermittent fault reproduction, and the quantitative relationships between intermittent fault and product damage can be further studied.

It is expected that the proposed methodology can help engineers to reproduce the intermittent fault behaviours to facilitate the detection and diagnosis of intermittent fault and to improve equipment safety.

The mechanism of electrical connector reproduction is analysed and the step-up stress test is used for intermittent fault reproduction.

Despite the wide dissemination and application of current signature analysis (CSA) in general industry, CSA is not commonly used in the wind industry, where the use of vibration signals predominates. Therefore, the purpose of this paper is to review the use of generator CSA (GCSA) in the online fault detection and diagnosis of wind turbines (WTs).

This is a bibliographical investigation in which the use of GCSA for the maintenance of WTs is analyzed. A section is dedicated to each of the main components, including the theoretical foundations on which GCSA is based and the methodology, mathematical models and signal processing techniques used by the proposals that exist on this topic.

The lack of appropriate technology and mathematical models, as well as the difficulty involved in performing actual studies in the field and the lack of research projects, has prevented the expansion of the use of GCSA for fault detection of other WT components. This research area has yet to be explored, and the existing investigations mainly focus on the gearbox and the doubly fed induction generator; however, modern signal treatment and artificial intelligence techniques could offer new opportunities in this field.

Although literature on the use of GCSA for the detection and diagnosis of faults in WTs has been published, these papers address specific applications for each of the WT components, especially gearboxes and generators. For this reason, the main contribution of this study is providing a comprehensive vision for the use of GCSA in the maintenance of WTs.

The purpose of this paper is to introduce an algorithm based only on local extreme analysis of a time sequence to further the detection and diagnosis of inter-turn short circuits and unbalanced voltage supply using vibration signals.

The upper and lower extreme envelopes from a modulated and oscillatory time sequence present a particular characteristic being of, theoretically, symmetrical versions with regard to amplitude reflection around the time axis. Thus, one may say that they carry the same characteristics in terms of waveforms and, consequently, frequency content. These envelopes can easily be built by an interpolation process of the local extremes, maximums and minimums, from the original time sequence. Similar to modulator signals, they contain more detailed and useful information about the required electrical fault frequencies.

Results show the efficiency of the proposed algorithm and its relevance to detecting and diagnosing faults in induction motors with the advantage of being a technique that is easy to implement in any computational code.

A laboratory investigation carried out through an experimental setup for the study of faults, mainly related to the stator winding inter-turn short circuit and voltage phase unbalance, is presented.

The main contribution of the work is the presentation of an alternative tool to demodulate signals which may be used in real applications like the detection of faults in three-phase induction machines.

The objective is the application of vibration analysis for the detection and diagnosis of low isolation between the stator coil wind and the voltage phase unbalance in induction motors with different numbers of poles. The purpose of this paper is to provide an approach for maintenance engineers for diagnosis electrical fault through the vibration analyses.

A detailed review of previous work carried out by some researchers and maintenance engineers in the area of machine fault detection is performed. By vibration analysis, the spectra were collected, which used to analyze the failure. Vibration spectra could detect particular characteristic for each fault in an initial condition, so the machine health can be preserved.

Results show the efficiency of the technique of vibration analysis and their relevance to detect and diagnose faults in different induction motors. In this way, it may be included in future predictive maintenance programs.

The paper presents a laboratory investigation carried out through an experimental set-up for the study of fault, mainly related to the stator winding inter-turn short circuit and voltage phase unbalance.

The main contribution of the paper has been the characterization of one more tool that makes the predictive maintenance process more efficient, effective and faster, increasing the reliability and availability of equipment.

This paper aims to clarify voltage sourced converter’s (VSC’s) influence rules on the alternating current (AC) short-circuit current and identify the key factors, so as to propose the short-circuit current suppression strategy.

This paper investigates the key factors which impact the short-circuit current supplied by the VSC based on the equivalent current source model. This study shows that the phase of the VSC equivalent current source is mainly affected by the type of fault, whereas the amplitude is mainly decided by the control mode, the amplitude limiter and the electrical distance. Based on the above influence mechanism, the dynamic limiter with short-circuit current limiting function is designed. The theoretical analysis is verified by simulations on PSCAD.

The short-circuit current feeding from VSC is closely related to the control mode and control parameters of the VSC, fault type at AC side and the electrical distance of the fault point. The proposed dynamic limiter can make VSC absorb more reactive power to suppress the short-circuit current.

The dynamic limiter proposed in this paper is limited to suppress three-phase short-circuit fault current. The future work will focus more on improving and extending the dynamic limiter to the fault current suppression application in other fault scenarios.

The research results provide a reference for the design of protection system.

The key influence factors are conducive to put forward the measures to suppress the fault current, eliminate the risk of short-circuit current exceeding the standard and reduce the difficulty of protection design.

The purpose of this paper is to present a study and analysis of insulation failure inter‐turn fault in induction machines (IMs).

A time stepping finite element method (FEM) analysis is performed for the study of IM with inter‐turn fault and determining the machine parameters (self and mutual inductances) after occurring fault. A simple dynamic model for IM with inter‐turn fault is presented. The model parameters are obtained by FEM analysis. An experimental test is also carried out to verify the results.

The behavior of IM is studied under various insulation failure inter‐turn fault conditions and severity using FEM. The paper's results help the machine designers to improve the fault tolerance as well the overall design of the machine drive system. It can also be useful for predict and detection of fault in IM.

Predicting and detection of turn faults in IM are in industry very helpful because it avoids the fully damage of IM and it is more easy to repair the machine. Designing a fault tolerant IM is required in some applications for increasing the reliability.

By using FEM for studying the fault, the machine parameters which are calculated with FEM and the study's results are very precise and accurate because the flux fluctuation after occurring fault has been taken into account. On the other hand, the fault model is very fast, global and accurate. It can be used in model‐based health monitoring systems.

Identify a new methodology for fault characterization, identification and location in electrical distribution systems, based on the use of matrix algebra.

The developed diagnostic methodology is based on a high precision analytical model of the network using a distributed parameters representation.

Test results have proved the approach to be efficient and precise, while providing a generalized quadripolar model of a line affected by the most common kinds of fault.

Generalization to a greater number of fault cases, experimental tests.

Utilities are quite interested in such items, since the new required quality standards put severe constraints on faults management and clearance. On the other hand, the system requires a rather complete measurement equipment of secondary substations.

The paper presents a new diagnostic technique for faults identification, location and characterization in distribution systems.

Interlaminar short circuits in turbo generator stators can lead to local damage of the iron core. The purpose of this paper is to model an interlaminar short circuit diagnosis test on an existing structure.

This work presents the modeling of short‐circuited laminations in a stator yoke of a turbo‐generator. A 3D finite element model, associated to a homogenization technique, is used to calculate the short‐circuit current. The diagnosis test known as El Cid has been modelled as well.

Calculation results are compared with the experiment. The same tendency has been observed both in experimental and numerical results.

Additional calculations may be performed (parametric studies) in order to investigate El Cid measuring under different conditions (different material properties, fault position, size), which may lead to a better interpretation of the results.

Modelling of short circuit diagnosis tests under different conditions may help with the interpretation of measuring results, predicting the fault size/seriousness and location. So, only the concerned parts of the stator have to be disassembled and repaired/rebuilt.

It is not easy to model numerically a structure with a short circuit inside, since different dimensions are involved: the fault and the varnish between laminations are much smaller than the stator itself. Thus, homogenization techniques have been used to model the lamination stack region. The combination of this technique with the modelling of the El Cid test constitutes a tool to study this kind of fault and calculate its severity and location in a stator.

The purpose of this paper is to identify a new and simple two‐end algorithm for fault location identification and characterization, in electrical distribution systems.

The developed diagnostic algorithm is based on a simple model of the network using a lumped parameters representation.

Test results have proved the approach to be efficient, allowing a precise fault identification and location while not requiring synchronized measures from the two ends.

There is a need for measurement systems at all MV/LV substations.

Applicability with limited investments is not possible where metering systems are not so diffused, although smart grids and DG units require such infrastructures. Moreover, utilities are quite interested in such issues, since the new required quality standards put severe constraints on faults management and clearance.

The paper presents a new and easier diagnostic algorithm for faults diagnosis in distribution systems.