Abstract: We present a promising technology for nonvolatile flexible electronic devices: A direct fabrication of epitaxial lead zirconium titanate (PZT) on flexible mica substrate via van der Waals epitaxy. These single-crystalline flexible ferroelectric PZT films not only retain their performance, reliability, and thermal stability comparable to those on rigid counterparts in tests of nonvolatile memory elements but also exhibit remarkable mechanical properties with robust operation in bent states (bending radii down to 2.5 mm) and cycling tests (1000 times). This study marks the technological advancement toward realizing much-awaited flexible yet single-crystalline nonvolatile electronic devices for the design and development of flexible, lightweight, and next-generation smart devices with potential applications in electronics, robotics, automotive, health care, industrial, and military systems.

Abstract: Permanent magnet (PM) machines are widely used in industrial processes due to their merits such as high power density and torque and low losses (high efficiency). These machines operate frequently under harsh conditions; therefore, they expose different types of faults. These faults can be diagnosed in initial stages using different techniques and prevent the faults' progress to catastrophic stages. One of the most important PM machine faults in terms of occurrence rate is demagnetization fault, whose causes can be heat, electrical, environmental or combinations. This may lead to efficiency drop, poor performance, and low reliability of the system. This paper attempts to review and summarize the demagnetization fault diagnosis methods in PM machines. First the fault generating factors and their impacts on the performance of the motor are discussed. Then, the recently developed techniques for demagnetization fault under stationary and nonstationary conditions in two separate sections are addressed. Presented methods are compared; their weaknesses and strengths are noted. Finally, suggestions for further research are proposed.

Abstract: The grid-connected inverters may experience excessive current stress in case of unbalanced grid voltage fault ride through (FRT), which significantly affects the reliability of the power supply system. In order to solve the problem, the inherent mechanisms of the excessive current phenomenon with the conventional FRT solutions are discussed. The quantitative analysis of three-phase current peak values is conducted and a novel current-limited control strategy is proposed to achieve the flexible active and reactive power regulation and successful FRT in a safe current operation area with the aim of improving the system reliability under grid faults. Finally, the simulation and experiments of traditional and proposed FRT solutions are carried out. The results verify the effectiveness of the proposed method.

Abstract: Power electronic systems have gradually gained an important status in a wide range of industrial applications such as renewable generation, motor drives, automotive, and railway transportation. Accordingly, recent research makes an effort to improve the reliability of power electronic systems to comply with more stringent constraints on safety, cost, and availability. The power devices are one of the most reliability-critical components in power electronic systems. Therefore, its condition monitoring plays an important role to improve the reliability of power electronic systems. This paper proposes a condition monitoring method of insulated-gate bipolar transistor (IGBT) modules. In the first section of this paper, a structure of a conventional IGBT module and a related parameter for the condition monitoring are explained. Then, a proposed real-time on-state collector–emitter voltage measurement circuit and condition monitoring strategies under different operating conditions are described. Finally, experimental results confirm the feasibility and effectiveness of the proposed method.

Abstract: The superior electro-thermal properties of silicon carbide (SiC) power devices permit higher temperature of operation and enable higher power density compared with silicon devices. Nevertheless, the reliability of SiC power modules has been identified as a major area of uncertainty in applications which require high reliability. Traditional power module packaging methods developed for silicon chips have been adopted for SiC and the different thermomechanical properties cause different fatigue stresses on the solder layer of the chip. In this paper, a 2-D finite element model has been developed to evaluate the stress performance and lifetime of the solder layer for Si devices, which has been validated using accelerated power cycling tests on Si IGBTs. The proposed model was extrapolated for SiC devices of the same voltage and current rating using the same solder material and the results show that under the same cyclic power loss profile the induced stress and strain energy in the die attach layer is much higher and concentrates on the die/solder interfacial area for SiC chips. Using the validated stress-based model, the lifetime can be quantified when SiC chips are used. This ability to extrapolate the available power cycling and lifetime data of silicon chips to SiC chips would be a key element for developing reliable packaging methods for SiC devices.

Abstract: Recently, the role of clothing has evolved from merely body protection, maintaining the body temperature, and fashion, to advanced functions such as various types of information delivery, communication, and even augmented reality. With a wireless internet connection, the integration of circuits and sensors, and a portable power supply, clothes become a novel electronic device. Currently, the information display is the most intuitive interface using visualized communication methods and the simultaneous concurrent processing of inputs and outputs between a wearer and functional clothes. The important aspect in this case is to maintain the characteristic softness of the fabrics even when electronic devices are added to the flexible clothes. Silicone-based light-emitting diode (LED) jackets, shirts, and stage costumes have started to appear, but the intrinsic stiffness of inorganic semiconductors causes wearers to feel discomfort; thus, it is difficult to use such devices for everyday purposes. To address this problem, a method of fabricating a thin and flexible emitting fabric utilizing organic light-emitting diodes (OLEDs) was developed in this work. Its flexibility was evaluated, and an analysis of its mechanical bending characteristics and tests of its long-term reliability were carried out.

Abstract: The investigation shows that power semiconductor devices are the most fragile components of power electronic systems.Improving the reliability of power devices is the basis of a reliable power electronic system, and in recent years, many studies have focused on power device reliability.This paper describes the current state of the art in reliability research for power semiconductor devices, mainly includes failure mechanisms,condition monitoring, lifetime evaluation and active thermal control.Among them,condition monitoring technology are classified and summarized by the failure mechanism and the change rules of characteristic quantities; The method of lifetime estimation isillustrated from the practical point of view;Methods of active thermal control are classified and summarized from the two ideas of reducing loss and loss compensation which are refined by the principle of realization. At last, this paper draws the existing problems and challenges of power devices reliability studies.

Abstract: GaN-based transistors with p-GaN gate are commonly accepted as promising devices for application in power converters, thanks to the positive and stable threshold voltage, the low on-resistance and the high breakdown field. This paper reviews the most recent results on the technology and reliability of these devices by presenting original data. The first part of the paper describes the technological issues related to the development of a p-GaN gate, and the most promising solutions for minimizing the gate leakage current. In the second part of the paper, we describe the most relevant mechanisms that limit the dynamic performance and the reliability of GaN-based normally-off transistors. More specifically, we discuss the following aspects: (i) the trapping effects specific for the p-GaN gate; (ii) the time-dependent breakdown of the p-GaN gate during positive gate stress and the related physics of failure; (iii) the stability of the electrical parameters during operation at high drain voltages. The results presented within this paper provide information on the current status of the performance and reliability of GaN-based E-mode transistors, and on the related technological issues.

Abstract: In this study, a fault-tolerant structure and its controlling method for a cascaded H-bridge multilevel inverter is introduced. When a fault occurs in one of the modules, the proposed circuit is able to isolate and eliminate the defective module from the whole system. The isolation and elimination is done by four relays in each module and a controlling circuit. This solution makes the system continue the normal operation by means of the remained healthy modules with decreased output voltage level. Therefore, the whole system failure will be prevented and higher reliability of the inverter will be guaranteed. Principles of operation and the controlling method are presented in this study. Reliability evaluation and comparison of the proposed fault-tolerant structure and the conventional one are considered. To ensure the correct performance of the proposed cascaded H-bridge multilevel inverter, a prototype has been synthesised in the laboratory. The obtained results affirm higher reliability and mean time to failure of the proposed circuit, so suitability of the proposed structure for sensitive industrial applications is confirmed.

Abstract: The More Electric Aircraft (MEA) initiative aims to increase the penetration of electrical systems in aircraft to decrease weight and further develop overall efficiency and reliability [1]. Newer aircraft, such as the Boeing 787 and the Airbus A380, have more electrical power installed compared with older models, and this trend is not expected to change any time soon. Although most aircraft feature some amount of electrical power, this is often limited to the electronics (i.e., flight or entertainment systems) or auxiliary systems (i.e., lighting or anti-icing). The core systems of the actuation still rely on hydraulic power.

Abstract: This paper proposes a new method for the investigation of the short-circuit safe operation area (SCSOA) of state-of-the-art SiC MOSFET power modules rated at 1.2 kV based on the variations in SiC MOSFET electrical parameters (e.g., short-circuit current and gate–source voltage). According to the experimental results, two different failure mechanisms have been identified, both reducing the short-circuit capability of SiC power modules with respect to discrete SiC devices. Based on such failure mechanisms, two short-circuit safety criteria have been formulated: 1) the short-circuit-current-based criterion; and 2) the gate-voltage-based criterion. The applicability of these two criteria makes possible the SCSOA evaluation of SiC MOSFETs with some safety margins in order to avoid unnecessary failures during their SCSOA characterization. SiC MOSFET power modules from two different manufacturers are experimentally tested in order to demonstrate the procedure of the method. The obtained results can be used to have a better insight of the SCSOA of SiC MOSFETs and their physical limits.

Abstract: In this paper, the effect of junction temperature swing duration on lifetime of transfer molded power insulated gate bipolar transistor (IGBT) modules is studied and a relevant lifetime factor is modeled. This study is based on 39 accelerated power cycling test results under six different conditions by an advanced power cycling test setup, which allows tested modules to be operated under more realistic electrical conditions during the power cycling test. The analysis of the test results and the temperature swing duration dependent lifetime factor under different definitions and confidence levels are presented. This study enables to include the t △ Tj effect on lifetime model of IGBT modules for its lifetime estimation and it may result in improved lifetime prediction of IGBT modules under given mission profiles of converters. A postfailure analysis of the tested IGBT modules is also performed.

Abstract: Current commercial battery management systems (BMSs) do not provide adequate information in real time to mitigate issues of battery cells such as thermal runway. This paper explores and evaluates the integration of fiber optic Bragg grating (FBG) sensors inside lithium-ion battery (LiB) coin cells. Strain and internal and external temperatures were recorded using FBG sensors, and the battery cells were evaluated at a cycling C/20 rate. The preliminary results present scanning electron microscope (SEM) images of electrode degradation upon sensor integration and the systematic process of sensor integration to eliminate degradation in electrodes during cell charge/discharge cycles. Recommendation for successful FBG sensor integration is given, and the strain and temperature data is presented. The FBG sensor was placed on the inside of the coin cell between the electrodes and the separator layers towards the most electrochemically active area. On the outside, the temperature of the coin cell casing as well as the ambient temperature was recorded. Results show stable strain behavior within the cell and about 10 °C difference between the inside of the coin cell and the ambient environment over time during charging/discharging cycles. This study is intended to contribute to the safe integration of FBG sensors inside hermetically sealed batteries and to detection of real-time temperature and strain gradient inside a cell, ultimately improving reliability of current BMSs.

Abstract: Modular multilevel converters (MMCs) will be extensively used in the high-voltage direct-current transmission networks because of its superior characteristics over line commutated converter. Increasing the reliability of the MMC is directly related to the balancing of the MMC submodule capacitors voltages, which guarantees the proper operation of the converter and lowers the stress on the submodules. This paper presents an adaptive voltage-balancing strategy based on the capacitor voltage estimation, utilizing a hybrid adaptive linear neuron recursive least squares scheme. The proposed strategy eliminates the need of measuring submodules capacitor voltages and associated communication link with the central controller. Furthermore, the estimated capacitor voltages are utilized to detect and localize different types of submodule faults. After isolating the faulty submodules, the proposed fault-tolerant control unit modifies the parameters of the voltage-balancing strategy to overcome the reduction of the active submodules. The dynamic performance of the proposed strategy is investigated, using PSCAD/EMTDC simulations and hardware-in-the-loop real-time simulations, under different normal and faulty operating conditions. The accuracy and the time response of the proposed fault detection and tolerant control units result in stabilizing the operation of the MMC under different types of faults. Consequently, the proposed integrated control strategy improves the reliability of the MMC.

Abstract: Reliability tests on 600V-rated GaN-based normally-off hybrid-drain-embedded Gate Injection Transistor (HD-GIT) are performed High-temperature reverse-bias test on HD-GIT reveals that the lifetime is dependent on the leakage current before the reliability test Acceleration factors for the temperature and reverse bias voltage are extracted Based on the obtained results, devices are designed so that their lifetimes under Vbs=480V (80% de-rated) at 80°C are longer than 1000 years, which are long enough for most conventional power converter applications Dynamic high-temperature operation life test is also performed, under which their DC characteristics are within their normal range up to 3600h In addition, HD-GITs are within their normal range under the similar reliability tests as applied for Si-based power transistors The physical mechanisms for the reliability of HD-GIT are discussed We conclude that the OFF-state reliability is explained by the so-called percolation degradation model, and that the hole injection from the p-type GaN embedded in the drain plays an important role to suppress the degradation under hard-switching operation test

Abstract: On advanced technology nodes, increases in power density, non-planar architectures and different material systems can exacerbate local self-heating due to active power dissipation, which can affect device performance and reliability in various ways This paper presents an overview of the research on self-heating in transistors and discusses modulators, measurement schemes, spatio-temporal sensitivities, and impacts on performance and reliability As the industry continues to scale dimensions and power densities, the significance of self-heating effects will continue to grow, and a robust frame-work to fully assess it, and deal with its impacts to circuits and IP blocks are essential

Abstract: Return on investment (ROI) analyses of solar photovoltaic (PV) systems used for residential usage have typically shown that at least 10 to 12 years is needed to break even, with this amount varying based on tax credits and reliability. This paper discusses the challenges with the reliability of current solar photovoltaic systems and the key reliability bottlenecks, with a focus on the ROI. The problem stems primarily from reliability issues of currently available power electronics hardware. This paper’s analysis of failure data shows that the short warranties and reliability concerns associated with solar PV inverters reduce the long-term ROI of residential solar PV systems by up to 10%. This paper, therefore, provides key insights for accurate ROI calculations for solar PV investments. Furthermore, methods to improve the reliability of PV inverters, such as selection of capacitors, inverter topology, and incorporating wide-bandgap semiconductor devices, are presented.

Abstract: Reliability of modern power systems, in particular those use wind and solar energies, is affected by the relatively short lifetime of the associated power electronic converters (PECs). Thermal stress has been identified as one of the commonest causes for failures in PECs. However, existing thermal monitoring systems are expensive, bulky and with no intelligent capabilities, which limit their full acceptance as monitoring and control tools in operational power plants. This work presents autonomous and inexpensive microcontroller-based system for monitoring and predicting thermal behaviour of switching devices used in PECs. System’s inputs are non-intrusively measured voltages and currents drawn by those devices while in operation. The developed system also determines lifetime consumption and has the ability to communicate with external monitoring and control systems e.g. supervisory, control and data acquisition (SCADA) platforms. The performance of the developed system was critically assessed and compared with high-resolution thermal imaging camera. Good agreement between both systems was achieved and the inexpensive developed system was found to have an accuracy of 95%.

Abstract: This paper proposes a fault-tolerant-cascaded quasi- Z -source dc–dc converter structure and investigates its reliability through a precise mathematical evaluation. In order to enhance the reliability of the suggested topology, a robust control method is considered, as well. According to the utilized control method, at the moment of fault occurrence, the defected modules are isolated from the converter by the virtue of some considered relays allowing the whole system keep working with the remained modules. Since the defected modules are eliminated from the circuit, the duty cycles of the switches will be changed through the controlling system, so that the remained modules take the responsibility of maintaining the output voltage in the desired level. Operation principle of the converter along with the control method (consists of fault detection and elimination systems) is provided. Additionally, a reliability evaluation technique is considered and, reliability comparison between the proposed, conventional and flyback structures is illustrated. Taking advantage of a laboratory-built prototype, the practicality of the suggested structure is proven. The obtained results confirm higher reliability and mean time to failure of the proposed converter compared to the conventional and flyback structures. Therefore, it could be counted as a suitable structure in sensitive industrial applications.

Abstract: Different functionalities can be incorporated into wind energy conversion systems (WECSs) in resilient microgrids in order to reduce the total system cost and to assist their self-healing capability. Meanwhile, wind industry-based reliability surveys have addressed that power electronics components are the most vulnerable parts in WECS. Therefore, thermal stresses and lifetime consumption of WECS are critical factors for evaluating the added functionalities and for developing new control strategies as well. Almost all of the previous methodologies in the literature tackle the problem of lifetime assessment of WECS using only the behavior of wind generation profiles and reactive power injection, which is limited by grid codes. Subsequently, these approaches cannot efficiently achieve lifetime assessment in case of resilient microgrid operation and different load demands. This paper proposes a more convenient approach for thermal behavior, and lifetime assessment for WECSs that considers the influence of the added DSTATCOM functionality, and various modes of resilient microgrids operation. Moreover, the proposed approach utilizes a joint probability distribution function (JPDF) that combines both of the collected field data of wind generation and load demand levels as well. The feasibility of the proposed approach has been verified analytically and compared to the previously addressed approaches. It can be concluded that thermal behavior and reliability assessment of WECS are highly impacted by the added DSTATCOM functionality.

Abstract: In this study, a new interleaved full soft switching DC-DC boost converter with a high power reliability is proposed. To achieve soft switching, a simple auxiliary circuit consisting of one switch, one diode, one inductor and two capacitors is employed in each single-phase DC-DC boost converter connected in parallel. All switches and diodes, including main and auxiliary ones, operate under soft switching conditions. These soft switching conditions consist of zero voltage and zero current switching (ZVZCS) for all switches and diodes at switching transitions except the output diodes, which turn off only with zero current switching. The soft switching technique used in this study decreases power losses which leads the converter to have higher efficiency and reliability. Also, the auxiliary circuit is located out of the main power path preventing high voltage and current stresses on the switches. In this study, operational modes analysis, design procedure, power reliability evaluations and laboratory prototype results with switching frequency of 20 kHz, input voltage of 48 V and output power of 40 W are presented.

Abstract: Selective laser melting, a laser-based additive manufacturing process, can manufacture components with good geometrical integrity. Application of the selective laser melting process for serial production is subject to its reliability on mechanical properties, especially on fatigue behavior, when it is required to be applied for dynamic applications. This study focuses on microstructural, quasistatic, high cycle fatigue (HCF), and very high cycle fatigue (VHCF) mechanisms of aluminum alloys manufactured by selective laser melting. Manufacturing of hybrid structures by selective laser melting process is also investigated. Microstructural features were investigated for process-induced effects and the corresponding influence on quasistatic and fatigue properties. The microstructural features can be controlled in the selective laser melting process for required properties. Joining strengths in hybrid structures can be improved by post process heat-treatments. Material constants in different fatigue regions were determined, and higher fatigue strength of hybrid alloys was achieved in HCF as well as VHCF regimes.

Abstract: One of the most important problems related to DC-DC converters is the phenomena of power switch failures. Therefore, applying soft-switching technique to these kinds of converters without adding extra active switch would improve their reliability. In this study, a new high reliable topology with the facility of the soft-switching operation for three-phase interleaved boost converter is proposed. The proposed structure is implemented by adding three inductors to the conventional structure. Automatically, the used power switches in the suggested topology, are turned on under zero voltage condition. In addition, the diodes are turned off under zero current condition. Using this method, the switching losses of semiconductors are reduced. Moreover, there is no additional active switch in the proposed topology. These two advantages cause the reliability of proposed topology to be significantly improved. The comparison results with other similar topologies are presented. Based on comparison results, it is shown that the reliability of the proposed topology is much better than others. Simulation and experimental results are compared with verifying the desired operation of the proposed structure.

Abstract: Device variability and reliability are becoming increasingly important for nano-CMOS technology and circuits, due to the shrinking circuit design margin with the downscaling supply voltage (V dd ) Therefore, robust design should have the awareness of both variability and reliability In FinFET technology, strong correlation between the variations of device electrical parameters is found, due to the larger impacts of line-edge roughness (LER) in FinFET structure Accurate compact models and new design methodology for random variability in FinFETs were proposed for the variation-and correlation-aware design For the reliability awareness, the impacts of BTI-induced temporal shift and the layout dependent aging effects should be taken into account for the optimization of end-of-life (EOL) performance/power/area (PPA) New-generation aging model and circuit reliability simulator for FinFETs were proposed and developed in industry-standard EDA tools Future challenges are also pointed out, such as statistical BTI and RTN The results are helpful for the robust and resilient design for 16/14nm and beyond

Abstract: Recent times have witnessed a significant positive trend in adoption of renewable energy sources and DC-based loads, which questions the efficiency and reliability of existing structure of electric...