This paper proposes a capacitor parameter estimation method based on wavelet transform and convolution neural network (CNN). By fully utilizing transforms the inherently non-ideal properties of bandpass filters, lowfrequency mid-frequency band features contained in voltages are extracted with high resolution. Leveraging these features, subsequent CNN simultaneously estimates two crucial aging indicators capacitors, i.e., capacitance equivalent series resistance (ESR). While most existing...

Nanostructured bainite is extremely resistant to severe tempering making it difficult reduce its hardness sufficiently allow certain processing before heat treatment into final state. An attempt therefore made introduce the divorced pearlite reaction that relies on presence of pro-eutectoid cementite in austenite order produce a microstructure containing spheroidal particles simply by continuous cooling from two phase and field. It demonstrated dramatically reduced values can be achieved...

This article proposes a capacitor condition monitoring (CM) method for modular multilevel converter (MMC) in motor drive applications. The proposed is based on wavelet decomposition of transient voltage signals, which independent modulation schemes and control strategies. equivalent series resistance (ESR) change can be detected with moderate computation requirement. Both simulation experimental results have verified the performance method.

Multichip IGBT module has been widely used in high-power converters. Detecting the status of chip is a cost-effective approach to improving reliability power devices. This article proposes novel method based on turn-off delay time detect fault multichip modules. First, effect failure process analyzed, which causes decrease time. Then, detection proposed, validated by experimental results. Furthermore, effects different working conditions are investigated through effective The tested results...

Operational and health management for the reliability of power electronic converters requires sensitive condition monitoring accurate estimation remaining lifetime. This study adds to second aspect by examining effects failure locations on junction temperature profiles under different conditions. It is found that die-attach solder fatigue direct bonding copper (DBC) fatigue, which occur frequently during serving time, have thermal loads. article investigates dependence stress output...

Bond wire lift-off is one of the major failure mechanisms in insulated gate bipolar transistor (IGBT) modules. Detecting fault bond wires important to avoid open-circuit IGBT ensure reliable operation power converters. In this paper, we propose a novel fatigue detection method for IGBT, which could be used normal working conditions. Firstly, investigated dependence on heatsink thermal resistance. An aging rate K was proposed compare measured resistance with initial value, indicate fatigue....

Junction temperature is the most important factor to induce insulated gate bipolar transistor module failure and conduct operational management. In-situ calibrated method junction calculation model are proposed timely indicate for electric vehicle drive system. It aims solve that conventional calibration methods need be in chamber cannot meet variable current conditions, which ignores effects of stray parameters electrode connection on on-state voltage. A mathematical estimation based...

Bond wires partial lift off is one of the major failure mechanisms lead to IGBT open-circuit fault. However it's difficult detect bond due IGBT's package. This paper proposes a new method based on thermal resistance assessment. An Finite Element Method (FEM) model established analyze how changed after off. Simulation results show validity this method.

Mg-1Mn-2Zn-1Nd alloy (mass %) has been developed for use as a hard tissue implant material. As-cast exhibited good biocompatibility and mechanical properties. To improve the corrosion performance strength of alloy, hot extrusion was applied on this alloy. The influence process microstructure, properties in vitro investigated by X-ray diffraction analysis, optical microscopy, scanning electron uniaxial tensile compressive tests, electrochemical immersion measurement. experimental results show...

Bond wire lift-off will cause an increase of remaining wires’ power dissipation, which usually is ignored for healthy modules. However, only partial dissipation transfers through thermal path from junction to case, lead overestimate the whole collector emitter pole and underestimate calculated resistance using proportion temperature difference dissipation. A FEM model established show change heat flow after bond wires were removed, increases, measured decrease lift-off. It validated by...

The orthogrid-stiffened FRP panel (OSFP) is a generic structural element in weight-sensitive structure applications. Based on the variational asymptotic method, 2D reduced-order plate model (2D-RPM) of OSFP was constructed through matching strain energy original for static and dynamic analyses. local field distributions were recovered using recovery relationship global response. relative influences select parameters effective performance revealed by parametric studies. comparative results...

With the extensive investment of wind turbine, it is significant to study reliability and lifetime estimation model its core components. Considering effect different failure sites on remaining lifetime, response converter at studied. It found that die attach solder fatigue DBC (Direct Bonding Copper) fatigue, which happen frequently during serving time, have effects thermal loads. A modified Cauer-type proposed according sites. Using a model, Remaining DFIG (Doubly Fed Induction Generator)...

Condition monitoring (CM) methods applied for power electronics can provide effective information predictive maintenance and prevent unexpected system downtime. This paper proposes a non-invasive in-situ CM method capacitors in modular multilevel converters. Unlike the conventional that monitor low-frequency signals, proposed focuses on high-frequency transient analysis. By analyzing voltage at capacitor's charging moment with wavelet decomposition, estimate equivalent series resistance...

The effects of geometrical imperfections on the collapse load and specific strength moderate-walled submersible vessel made Ti6Al4V-laminate composites Ti6Al4V alloy, respectively, have been investigated in this study. Two kinds imperfections, which are initial ovality along cross -section direction winding-induced waves longitudinal symmetric axis, considered. numerical analyses including non-linear finite element (FE) elastic-plastic buckling analysis performed by commercial software MSC...