Recently, research concerning electrical machines and drives condition monitoring and fault diagnosis has experienced extraordinarily dynamic activity. The increasing importance of these energy conversion devices and their widespread use in uncountable applications have motivated significant research efforts. This paper presents an analysis of the state of the art in this field. The analyzed contributions were published in most relevant journals and magazines or presented in either specific conferences in the area or more broadly scoped events.

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Advances in Electrical Machine, Power Electronic, and Drive Condition Monitoring and Fault Detection: State of the Art

This paper presents an open-circuit fault detection method for a grid-connected neutral-point clamped (NPC) inverter system. Further, a fault-tolerant control method under an open-circuit fault in clamping diodes is proposed. Under the grid-connected condition, it is impossible to identify the location of a faulty switch by the conventional methods which usually use the distortion of outputs because the distortion of the outputs is the same in some fault cases. The proposed fault detection method identifies the location of the faulty switch and the faulty clamping diode of the NPC inverter without any additional hardware or complex calculations. In the case of the clamping diode faults, the NPC inverter can transfer full rated power with sinusoidal currents by the proposed fault-tolerant control. The feasibility of the proposed fault detection and the fault-tolerant control methods for the grid-connected NPC inverter are verified by simulation and experimental results.

Open-Circuit Fault Diagnosis and Fault-Tolerant Control for a Grid-Connected NPC Inverter

This paper presents a real-time diagnostic algorithm for insulated-gate bipolar transistor open-circuit faults in three-level neutral-point-clamped rectifiers. This algorithm is based on the instant voltage error in the converter and requires only signals already available to the control system, avoiding the use of additional hardware. The algorithm is independent from the load and from the used control strategy and provides very fast detection and identification of the fault, with diagnostic times as low as two sample periods (in favorable conditions). Experimental results are presented for the operation of the rectifier with two distinct control and modulation strategies and in different conditions. Results show the algorithm's speed, effectiveness, and robustness.

Real-Time IGBT Open-Circuit Fault Diagnosis in Three-Level Neutral-Point-Clamped Voltage-Source Rectifiers Based on Instant Voltage Error

This paper presents a model-based open-circuit fault diagnosis approach for single-phase three-level neutral-point-clamped (3LNPC) converters in electric railway application. The diagnosis algorithm, which only requires the signals existing in the control system, not only detects open-circuit faults but also identifies the faulty device among the transistors and clamping diodes. The mixed logical dynamic (MLD) model of the converter is built to estimate the grid current. The residual generated from the measured current subtracting the estimated one is analyzed under different open-circuit faults. According to the characteristics of the residual changing rate, the proposed approach allows fault localization. The proposed method is effective both in traction and regenerative braking operation and has fast diagnosis speed. Hardware-in-the-loop (HIL) experiments are carried out to verify the effectiveness of the proposed fault diagnosis algorithm.

An Open-Circuit Fault Diagnosis Approach for Single-Phase Three-Level Neutral-Point-Clamped Converters

Fault diagnosis is a problem processing variable information obtained from different sources in nature. Evidence theory, efficient to deal with information viewed as evidence, is widely used in fau...

https://journals.sagepub.com/doi/pdf/10.1177/1687814018809184

Engine fault diagnosis based on sensor data fusion considering information quality and evidence theory

This study presents a new fault diagnostic technique for a semiconductor open-circuit fault in a neutral-point clamped inverter, based on the average current Park's vector approach. This method relies on the measurement of two motor line currents and is able to perform a complete diagnosis in less than half of the inverter output current period. The implementation of this diagnostic technique requires no additional current or voltage sensors besides the ones already used by the control algorithm of the converter. The diagnostic method uses the modulus and angle of the normalised average current Park's vector to detect the fault and identify the faulty insulated gate bipolar transistor (IGBT) pair, respectively. Simultaneously, the normalised average values corresponding to the positive and negative parts of the motor supply currents waveforms are used to identify the inner faulty IGBTs with even and odd numbers, respectively. The diagnostic method is also robust to transient conditions imposed by load and speed variations. The performance and effectiveness of the proposed diagnostic technique are validated both by the simulation and experimental results.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-pel.2013.0416

Fault diagnostic algorithm for three-level neutral point clamped AC motor drives, based on the average current Park's vector

A new real-time method able to diagnose multiple semiconductor open-circuit (OC) faults in a three-level neutral-point clamped inverter is introduced in this paper. The proposed diagnostic method is based on the evaluation of the output pole voltages and output currents of the inverter. The proposed method allows a real-time detection and localisation of multiple OC faults in all active power switches and clamp-diodes within one modulation period. Experimental results obtained for different operating conditions of the inverter demonstrate the applicability and performance of the proposed diagnostic approach.

Method to diagnose open-circuit faults in active power switches and clamp-diodes of three-level neutral-point clamped inverters

This paper presents a diagnosis method for the detection and location of open-circuit faults in 3-Level NPC inverters with SVPWM modulation scheme based on even-order harmonic elimination. The performance of the NPC inverter under normal and faulty conditions is firstly investigated both by simulation and experiments. Afterwards, a method for inverter diagnosis is proposed, based on the Average Current Park's Vector. This method proved to be capable of detecting and locating the phase and the semiconductor pair where the faulty IGBT is located.

Three-level NPC inverter fault diagnosis by the Average Current Park's Vector approach

The hierarchical nacre-like three-dimensional (3D) assembly of porous and lightweight materials is in high demand for applications such as sensors, flexible energy storage and harvesting devices, electromagnetic interference shielding, and biomedical applications. However, designing such a biomimetic hierarchical architecture is highly challenging due to the lack of experimental approaches to achieve the necessary control over the materials' microstructure on the multilength scale. Aerogels and foam-based materials have recently been developed as attractive candidates for pressure-sensing applications. However, despite recent progress, the bottleneck for these materials to achieve electrical conductivity combined with high mechanical flexibility and fast strain recovery remains. In this study, for the first time, inspired by the multiscale architecture of nacre, we fabricated a series of ultra-lightweight, flexible, electrically conductive, and relatively high-strength composite foams through hybridizing the cross-linked silk fibroin (SF) biopolymer, extracted from Bombyx mori silkworm cocoon, reinforced with two-dimensional graphene oxide (GO) and Ti3C2 MXene nanosheets. Nacre is a naturally porous material with a lightweight, mechanically robust network structure, thanks to its 3D interconnected lamella-bridge micromorphology. Inspired by this material, we assemble a cross-linked SF fibrous solution with MXene and GO nanosheets into nacre-like architecture using a bidirectional freeze-casting technique. Subsequent freeze-drying and gas-phase hydrophobization resulted in composite foams with 3D hierarchical porous architectures with a unique combination of mechanical resilience, electrical conductance, and ultra-lightness. The developed composite presented excellent performances as piezoresistive pressure-sensing devices and sorbents for oil/water separation, which indicated great potential in mechanically switchable electronics.

Nacre-Mimetic, Mechanically Flexible, and Electrically Conductive Silk Fibroin-MXene Composite Foams as Piezoresistive Pressure Sensors.

In this study, a wound rotor induction machine, as the core of a doubly-fed induction generator (DFIG) system, is modelled using the magnetic equivalent circuit approach. The entire DFIG system is implemented in Matlab/Simulink environment, including the machine model, power converters, control system and the grid. The model, which includes the ability to simulate rotor inter-turn short-circuits (RITSCs), is subsequently used for the investigation and comparison of the impact of this fault in several DFIG quantities, namely in the stator current and in some control variables. This research also deals in detail with the differences found when comparing RITSC and unbalanced rotor resistance (URR) faults. It is observed that on the contrary to the URR, the stator current spectrum is more appropriate than the control signals for the detection of RITSC. Simulation and experimental results obtained with a DFIG system operating at sub-synchronous and super-synchronous speeds, for different values of the active and reactive powers injected into the grid, corroborate the findings reported in this study.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-rpg.2016.0189

Mohsen Bandar Abadi

Papers

Fault diagnostic algorithm for three-level neutral point clamped AC motor drives, based on the average current Park's vector

Method to diagnose open-circuit faults in active power switches and clamp-diodes of three-level neutral-point clamped inverters

Three-level NPC inverter fault diagnosis by the Average Current Park's Vector approach

Nacre-Mimetic, Mechanically Flexible, and Electrically Conductive Silk Fibroin-MXene Composite Foams as Piezoresistive Pressure Sensors.

Magnetic equivalent circuit modelling of doubly-fed induction generator with assessment of rotor inter-turn short-circuit fault indices