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The development of Condition-Based Maintenance and Prognostics and Health Management systems can be fostered by models that accurately reproduce the effects and propagation of faults. Conventional methods applied to the analysis and simulation of rotor asymmetries in induction machines are based in the classical 2-D finite element approach, which is unable to reflect its complex effects, such as interbar...
Wide bandgap semiconductor devices in machine drive topologies are becoming more prevalent. These devices improve efficiency and can operate at higher switching frequencies. However, higher switching frequencies will increase the electrical stress applied to the insulation of the machine. Electrical stress, excessive heating, mechanical vibrations, and environmental contamination are leading factors...
Electric road systems (ERS) are an emerging technology driven by the growing need for electric propulsion of land transports. Electric vehicles, supplied by energy from charging when standing still, have significantly more limited operating range than vehicles supplied by combustible fuels. Electric road systems allow the electric vehicles to charge continuously while driving, making the electric...
This paper presents a new algorithm for the practical implementation on embedded devices of the extended current Park's vector approach (EPVA), which substantially reduces the hardware and computational requirements needed for applying this technique. The EPVA is a proven technique for fault diagnosis of induction motors working in steady state regime. However, this approach has some practical limitations:...
Aluminum electrolytic capacitors (AECs) are the most common capacitors used in power electronics. They are frequently used for filtering and storage functions because of their small size, large capacitance and low price. However, AECs also represent the major cause for power electronics equipment breakdown, mainly due to their wear out through the vaporization of the electrolyte, as a result of both...
This paper proposes a single fault diagnostic method for regenerative permanent magnet synchronous machine drives with the ability to handle IGBT faults, current sensor faults and mechanical sensor faults. The robustness against false alarms of the proposed technique is improved by using adaptive thresholds and normalized diagnostic variables. The proposed algorithm requires the information given...
The concept of Frequency Response Analysis (FRA) has been widely accepted as a reliable diagnostic tool to detect winding and core deformations within power transformers. While the measurement of transformer FRA signatures has been standardized since the development of advanced frequency response analyzers, interpretation of the FRA signature which is provided as a graphical plot is still challenging...
This paper proposes a generalized logic-based method for fault diagnosis in multilevel inverters that can be integrated with reconfiguration methods. Thus, both effective fault diagnosis and fault tolerance can be accomplished. To validate such integration, the proposed fault diagnosis method is applied to a five-level neutral point clamped inverter with three reconfiguration methods proposed in the...
The paper deals with the reactive power compensation in single-phase systems by active power line conditioners (APLCs), focusing on the effectiveness of the compensating action when the utility voltage is distorted. The existing compensation approach, based on the achievement of a sinusoidal load current, is first presented, showing that it suffers from some shortcomings. A novel compensation approach,...
This paper proposes an improved battery management system (BMS) that provides supervisory monitoring and active cell-to-cell equalization in order to protect the battery lifespan in an electric vehicle (EV). This can be accomplished through a Supercapacitor (SC) bank that can store and then recover electric energy to any weak cell of the EV battery bank. Specifically, the proposed control scheme online...
In this paper, the sun gear tooth fault in a one-stage planetary gear is studied in a representative electromechanical system. The aim is to use both electrical and mechanical signatures of a wound rotor induction generator for fault diagnosis through both numerical simulation and experimental approaches. In this regard, a dynamic model of the system, which includes all mechanical components in the...
This paper presents an online nonparametric frequency response estimation approach for the identification of rotor dynamics of a high-speed machine supported by an active magnetic bearing (AMB) system. The closed-loop identification estimation approaches (direct and indirect) are based on a sliding discrete Fourier transform (SDFT) method that is applied in conjunction with a known multisine excitation...
The feasibility of using stator current measurements in order to detect mechanical problems in electric rotating machinery has been proven by many authors several decades ago. However, this way of detecting problems has never been exploited as a full-covering and reliable prognostic monitoring technology. Although the imposed current-signatures of different evolving mechanical faults in electric machines...
The recent trend in squirrel cage induction motor manufacturing is to replace fabricated copper rotors with aluminum die-cast rotors to reduce manufacturing cost to stay competitive in the global market. Porosity in aluminum die-cast squirrel cage rotors is inevitably introduced during the die cast process. Porosity can cause degradation in motor performance and can lead to a forced outage causing...
The three-phase induction motor is one of the most employed equipment in industrial premisses. Despite of its reliability and robustness, these machines can present faults due to the operation time, harsh operating conditions, voltage unbalance, among other factors. In this work, a methodology for intelligent diagnose of multiple faults in induction motors by using a discretization of currents and...
This paper presents the results of an experimental investigation on the harmful effects due to the PWM inverter supply on low voltage induction motors. Laboratory tests have verified on two different models of motors the reflected wave phenomenon, which induces on their terminals a rising voltage edge with peaks higher than twice the DC link voltage; further tests in a qualified firm have revealed...
A comparison of bending speed and experimental setups using 3-point or 4-point bending for introduction of flex cracks into multilayer ceramic capacitors (MLCCs) in a controlled manner is presented. The impact of bending speed and corresponding strain rates on the formed flex cracks detected by X-ray imaging and optical microscopy images of cross-sectioned MLCCs are examined. Furthermore, the critical...
The realization of electromagnetic devices may implies the presence of local losses caused by material defects or by magnetic anomalies caused by mechanical processing. The problem of such defects location is the object of the present work; the aim of obtaining information about imperfections or defects with a non invasive inspection has been pursued. The adopted approach is based on the observation...
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