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In permanent magnet servo motors, each component has a certain temperature limit. For on-machine device with electronic components, like the high resolution optical encoder, the temperature limit is commonly less than 125°C. While for the motor body, the winding and the magnets usually have higher temperature limit. During continuous operation, the encoder temperature, rather than the winding or magnet...
Rotor eccentricity in permanent magnet synchronous motors (PMSMs) increases unbalanced magnetic pull and motor vibration resulting in accelerated aging of motor components. If eccentricity remains undetected, it can increase in severity, and increase the risk of stator-rotor contact, which causes forced outage of the motor and driven process. Detection of eccentricity currently relies on off-line...
This paper addresses the development of electro-thermal models able to accurately predict the thermal behaviour of power modules in AC drives. The model would be implemented in the digital signal processor used to control the drive, operating therefore on line. FEM will be used for the design and calibration of the models. The performance of the proposed methods will be validated experimentally.
Electrical equipment has to carry the rated normal current and short time withstand current. As shown in previous publications, the voltage-temperature relation allows calculating the temperature of contact elements and connectors for steady- state operating points. In the case of transient electric-thermal load, a finite-element analysis (FEA) is required to calculate the time-dependent distribution...
This paper discusses the problem offitting parameters of a detailed circuit thermal model when the complete data on problem geometry or material properties are not available. The problem is illustrated based on a practical example of a test hybrid circuit. Unknown model parameter values are determined here from dynamic temperature measurement results which were processed employing the Network Identification...
This paper presents an electro-thermal based junction temperature (Tj) estimation method of insulated gate bipolar transistor (IGBT) power module. Firstly, the internal structure of IGBT and its transient characteristics are researched, through which the factors affecting the power loss as well as its basic influence rule are analyze and the multivariable loss calculation model is obtained. And then...
A three-dimensional finite element model of miniature circuit breaker is established. The steady state temperature field is obtained by the method of electrothermal coupling, and the mechanism of overload protection is analyzed. The influence of wire size on the temperature of bimetal is studied. A simple and effective method to reduce the influence of external wire size is presented. The influence...
The core temperature of power cables is a key supervising factor which concerns the operation safety of transmission line. However, direct measurement influences insulation performance due to embedding instruments into the cable. In this paper a measurement method using temperature retrieval is proposed. The finite element models of the cable are established for excavating the implicit relationships...
In phosphor-converted light-emitting diodes (pc-LEDs), phosphor heating can lead to decrease of luminous efficiency or even thermal quenching due to local high phosphor temperature. Phosphor scattering model has been used to calculate the phosphor heat generation. Using this model, there are two methods for heating power estimation, one is the subtractive method and the other is the integral method...
The solder joints model structure of SMT has been established. The general rules of three different positions(the shallow surface, the internal and the interface of solder and pad)were discussed. Then, the finite model has been checked by the combination of experiment and simulation. Finally, through the multi points scanning method, the heat source was applied to heat the solder joints, the temperature...
This paper presents a cryogenically cooled, dual polarization, low noise Phased Array Feeds receiver for radio astronomy application, which operated at 4–8 GHz. It is designed to be mounted at the focal plane of a dish antenna by producing 4 dense covered, simultaneously operated beams with benefits of increasing Field of View, survey speed, and improving the aperture efficiency of the dish. Development...
A cathode material of a low work function is needed to achieve a high performance electron source. We measured the work function of W(100) surface modified with Y2O3 by using of photoemission electron microscope. The work function of Y-oxide/W(100) surface is measured to be 2.5eV. Field emission characteristics is measured with Y-oxide/W emitter and work function is estimated by N-F plots.
High brightness and stable cathode has been required for SEM use. We have been studied about Tungsten Carbide (WC) field emission cathode to achieve low-cost and easy to use, high brightness cathode. Tungsten carbide layer is formed on W-FE tip by heating in Ethylene(C2H4) gas. This WC field emission cathode indicated low work function.
Thermoelectric generators (TEG) have been widely used as autonomous energy sources for a wide spectrum of applications that require output power from several mW to several W. The paper below presents simulation results compared to the experiments for the two mass production TEG types. TEGs have been simulated based on the finite element method (FEM) within ANSYS Workbench software platform, which...
The importance of the mechanical behavior of electronic packages starts at the beginning of the package assembly process and continues through performance testing procedures at different levels. Predicting an electronic package's mechanical performance by simulation is an ongoing challenge and pursuit of both industry and academia. To achieve this goal, advanced simulation or analyses should have...
The Glass interposer is proposed as a superior alternative to organic and silicon-based interposers for 3D IC (Integrated Circuit) packaging and 2.5D TSV (Through Silicon Vias) package in the near future. The several attractive advantages such as excellent electrical isolation, better RF performance, better feasibility with CTE, could be fabricated with large size. However, the thin glass is extremely...
This study focuses on the understanding of moisture diffusion physics under use conditions (UC) and its impact on definition of qualification requirements. It uses computational modeling and detailed measurements of UC to challenge some long held assumptions used in moisture risk assessments. It introduces the quantity called "Stable Wetness" to account for moisture amount present in the...
This paper discusses the effect of uneven axial magnet temperature of permanent magnet assisted synchronous reluctance motor (PMa-SynRM) on unbalanced magnetic pull (UMP). The loss generated in stator and rotor contribute to temperature rise in the motor. Commonly, radial direction thermal analysis has been done while assuming constant temperature in axial direction of a machine. However, the uneven...
Fan-Out (FO) chip on substrate is one of the fan-out solution for package integration. This solution brings the short interconnection between die to die for excellent electrical performance. Fan-Out chip on substrate device provides excellent electrical performance in multi-die connection,. The multiple re-distribution layer (RDL) processing is implemented in advance multi-dies FO chip on substrate...
Thermo-compression bonding (TCB) is an important electronic packaging process which applies heat and pressure to form arrayed interconnections in simultaneity. TCB processes need to be optimized to ensure low thermal variation in order to produce uniform and reliable bonds. Due to the form factors and complex structures involved in TCB, it is difficult to determine thermal variations during bonding...
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