Gallium nitride high-electron-mobility transistors (GaN-HEMTs) suffer from trapping effects that increases device on-state resistance (RDS(on)) above its theoretical value. This increase is a function of the applied dc bias when in off state, and time which biased for. Thus, dynamic RDS(on) different commercial GaN-HEMTs are characterised at voltages paper by proposed new measurement circuit. The time-constants associated with detrapping extracted using circuit it shown variations can be...

Virtual prototyping of power electronic modules aims to allow rapid evaluation potential designs without the need resort building and testing physical prototypes. A key requirement for this process is ability quickly generate small, compact models describing thermal performance a design study presents novel approach model generation process. The starts with finite-difference mesh proposed applies fast sparse matrix solver (GMRES) determine steady-state response particular input. In doing...

The specific thermal resistance values of several interface materials (TIMs) intended to thermally enhance Cu contact pairs and their degradation under isothermal ageing at 170 °C have been investigated using stack samples consisting 10 discs 9 layers the TIMs. results obtained indicate that as-prepared samples, one with conductive Ag grease, Sn–3.5Ag solder joints 25 μm thick Sn foil as TIMs are significantly lower than those sample without any TIM. However, after for 90 days, these not...

The need for multidisciplinary virtual prototyping in power electronics has been well established, however, design tools capable of facilitating a rapid iterative process do not exist. A key challenge developing such is identifying and modeling techniques which can account 3-D geometrical choices without unduly affecting simulation speed. This addressed this paper using model order reduction prototype electronic tool incorporating these presented. relevant electrothermal module example then...

A model for the evolution of a thin liquid coating on horizontal cylinder is presented. The rotates about its axis, carrying around circumference. For viscous coating, this leads to formation relatively thick where surface moves upward. based lubrication theory, as compared radius, and includes effects rotation, gravity, tension, flow along axis. two-dimensional numerical scheme finite differences produced, investigation case when axial neglected. This validated in appropriate limiting...

(This study is for special section 'Design, modelling and control of electric drives transportation applications') The conduction switching losses silicon carbide (SIC) gallium nitride (GaN) power transistors are compared in this study. Voltage rating commercial GaN <650 V, whereas that SiC <1200 V. This begins with a theoretical analysis examines how the characteristics 1200 V metal–oxide–semiconductor field-effect transistor (MOSFET) change if device design re-optimised 600 blocking...

Because of trapped charges in GaN transistor structure, device dynamic on-state resistance $R_\mathrm{DSon}$ is increased when it operated high frequency switched power converters, which possibly by zero voltage switching (ZVS) to reduce its turn-on losses. When finishes ZVS during one period, has been under both reverse and forward conduction. Therefore conduction modes needs be carefully measured understand For this reason, a measurement circuit with simple structure fast response proposed...

We present three-dimensional numerical simulations of the flow a thin liquid coating on rotating horizontal right circular cylinder. The motion is described using lubrication model. model evolution equation discretized and solved numerically an alternating-direction implicit algorithm. cylinder rotates about its axis, carrying around circumference, resulting in formation relatively thick where surface moves upward. For coatings which are initially nearly uniform along this results ridge...

GaN-HEMTs suffer from trapping effects which might increase device ON-state resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS(on)</sub> ) values. Thus, dynamic R of a commercial GaN-HEMT is characterized at different bias voltages in the paper by proposed measurement circuit. Based on reaults, behavioural model to represent values, and detrapping time constant represented series RC network. The simulated PSPICE, simulation results...

New types of stationary solutions a one-dimensional driven sixth-order Cahn–Hilliard-type equation that arises as model for epitaxially growing nanostructures, such quantum dots, are derived by an extension the method matched asymptotic expansions retains exponentially small terms. This yields analytical expressions far-field behavior well widths humps these spatially nonmonotone in limit driving force strength, which is deposition rate case epitaxial growth. These extend family monotone...

Ultrasonically bonded heavy Al wires subjected to a small junction temperature fluctuation under power cycling from 40°C 70°C were investigated using non-destructive three-dimensional (3-D) x-ray tomography evaluation approach. The occurrence of irreversible deformation the microstructure and wear-out such conditions demonstrated. observed microstructures consist interfacial inter-granular cracks concentrated in zones stress intensity, i.e., near heels emanating interface precracks....

SiC and GaN power transistors switching energy are compared in this paper. In order to compare E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sw</sub> of the same rating device, a theoretical analysis is given device conduction loss losses change when maximal blocking voltage reduces by half. After that, 650V GaN-HEMT measured hard condition with that 1200V SiC-MOSFET current rating, which it shown smaller than SiC-MOSFET, SiC-MOSFET....

In order to model GaN-HEMT switching transients and determine power losses, a compact including dynamic RDSon effect is proposed herein. The includes mathematical equations represent device static capacitance-voltage characteristics, behavioural voltage source, which multiple RC units different time constants for trapping detrapping from 100 ns s range. All the required parameters in can be obtained by fitting method using datasheet or experimental characterisation results. then implemented...

GaN power transistors are drawing extensive research interest to increase electronics systems efficiency and density for electrical vehicles (EV). However, devices suffer from current collapse, which results in shifted device static characteristics. In this paper, different measurement methods proposed investigate the influence of transistor collapse on conduction switching losses. By proposing a circuit accurately characterise dynamic RDSon, it is shown that RDSon increases 60\% bigger than...

In order to model GaN device dynamic R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DSon</sub> value due trapped charge, a measurement circuit accurately measure under different OFF-state time and ON-state is at first proposed. Based on results, an analytical with cells proposed represent evolution. It then represented as behavioural voltage source compensate V xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> voltage, which can be...

Using virtual prototyping (VP) design tool to evaluate power converter electro-thermal performance can help designers validate prototype in a quick way. However, different system time-scale requires efficient simulation techniques. Thus, an approach by using average losses of one switching cycle is presented the paper decouple electrical and thermal so as influence parasitic inductance on device junction temperature quickly. This validated comparing with method obtain instantaneous losses....

Virtual prototyping (VP) is very important for power electronics systems design. A virtual design tool based on different modelling technology and model order reduction proposed in the paper. In to combine circuit electromagnetic with semiconductor device models, a SiC-JFET behavioural presented implemented tool. half bridge using devices thus represented VP software. The then validated by comparing experimental measurements switching waveforms.

This paper compares the 1972 Norms Edition of Stanford-Binet Intelligence Scale, Form LM, and Wechsler Scale for Children, Revised (1974), from a practitioner's viewpoint The strengths weaknesses each instrument are explored in relation to (a) standardization data given manuals, (b) ease administration interpretation, (c) age-range limitations finally, (d) utility both instruments as aids prediction academic success.

A novel approach is presented that shows how mathematical optimisation algorithms can be applied to optimise multi-chip power electronic modules based on their dynamic thermal performance. By using Model Order Reduction techniques which allow rapid simulation and evaluation of potential designs, even require a large number design evaluations used determine theoretical optimum designs within realistic time-scales standard desktop PC. The has been integrated into prototype electronics software...

On a tilted heated substrate, surface tension gradients can draw liquid up out of reservoir. The resulting film thickness profile is controlled by two parameters, which depend on the tilt imposed temperature gradient, and postulated thin precursor layer. evolution this in time studied using lubrication model. A number distinct behaviors are possible as substrate angle other parameters varied. Recent results for multiple stationary profiles near meniscus used, interaction these with advancing...