scholarly journals Research of ZnO Arrester Deterioration Mechanism Based on Electrical Performance and Micro Material Test

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2624
Author(s):  
Qizhe Zhang ◽  
Shenghui Wang ◽  
Xinghao Dong ◽  
Mingliang Liu ◽  
Qi Ou ◽  
...  
Keyword(s):  
High Speed ◽  
Performance Test ◽  
Chemical Elements ◽  
Energy Dispersive Spectrometer ◽  
Working Environment ◽  
Electrical Performance ◽  
Aluminum Electrode ◽  
Electrode Layer ◽  
Term Operation ◽  
Deterioration Mechanism

The traction power supply system of an Electrical Multiple Unit (EMU) often suffers from overvoltage impact. As an important protection device for on-board electrical equipment, the working environment of a roof arrester is worse than that of a power system. In recent years, the explosion failure of the roof arresters of an EMU has occurred from time to time, which seriously endangers the safe operation of high-speed railways. In this paper, the electrical performance test and material micro test of roof arrester in three states of normal, defect, and exploded, are carried out in order to study the internal causes of roof arrester explosion and clarify its deterioration mechanism. Using the DC reference voltage test and leakage current test, the electrical performance differences of normal, defective, and exploded arresters are obtained. By studying the disassembly of an arrester, the appearance characteristics of arrester varistor in three states are obtained. The micro morphology and chemical elements of the varistor are analyzed by Scanning Electron Microscope and Energy Dispersive Spectrometer. The deterioration mechanism of the arrester varistor is then revealed, and preventive measures for the explosion failure of the roof arrester are put forward. The obtained results show that, during the long-term operation of the roof arrester of an EMU, the varistor may be damp, and therefore the aluminum electrode layer and side insulation layer of the varistor may deteriorate. After the deterioration of the aluminum electrode layer, the content of the O element increases, and multiple film structures are formed on the surface. After the deterioration of the side insulating layer, the content of the O element increases, and the surface becomes uneven. Improving the sealing performance requirements of the roof arrester and optimizing the maintenance process can reduce its explosion failure.

scholarly journals Integrated Durability of Automobile Alternator Test System Design Based on LabVIEW

2014 ◽  
Vol 8 (1) ◽  
pp. 839-845 ◽  
Author(s):  
Wu Weibin ◽  
Feng Yue ◽  
Du Junyi ◽  
Xu Pengbo ◽  
Feng Yunlin ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Automotive Industry ◽  
Virtual Instrument ◽  
Measurement Errors ◽  
High Speed ◽  
Performance Test ◽  
Test System ◽  
Electrical Performance ◽  
Durability Test ◽  
Limit Test

New standards in the automotive industry highlighted the situation of the actual operation of the alternator and a variety of harsh environment simulation limit test. Using new standards in the automotive industry as a guide, this article presents a virtual instrument based on the durability of automobile generator integrated test system. The design adopt virtual instrument technology in designing the system, Graphic language, LabVIEW is applied in writing measure-control program. The system uses a lot of features on LABVIEW, including Data acquisition, control of serials port, etc. Test implementation uses the host computer via RS232 and RS485 communication port and the data acquisition card, NI PCI- 6221, to control the frequency hybrid motor, temperature control box, electronic loads and other intelligent devices, and to simulate a variety of automotive alternator working conditions and real-time monitoring to monitor the status of generators. Using this system, two separate automobile alternators can be tested in terms of high-speed vehicle impact and high temperature durability test and electrical performance test and other tests at the same time. As a result, the generator speed measurement error is within 1%, the control error is within 2%, voltage and current measurement errors were within 0.5% and 0.4%, which meets the requirements.

scholarly journals Research on Performance Test System of Space Harmonic Reducer in High Vacuum and Low Temperature Environment

Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Performance Test ◽  
High Reliability ◽  
High Vacuum ◽  
Test System ◽  
Low Noise ◽  
Speed Ratio ◽  
Space Harmonic ◽  
Temperature Environment

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.

The Study of Thermal Raising and Transmission Torque of High Speed Ball-Screw Lubricated by Different Greases

2015 ◽  
Vol 642 ◽  
pp. 212-216
Author(s):  
Yi Haung ◽  
Chin Chung Wei
Keyword(s):  
Contact Area ◽  
Axial Load ◽  
High Speed ◽  
Performance Test ◽  
Vertical Motion ◽  
High Viscosity ◽  
Ball Screw ◽  
Frictional Heat ◽  
Motion Platform ◽  
Base Oil

Ball screw is a high-precision and high performance linear drive of mechanical elements. The frictional heat of internal components what is very significant impact for platform transmission in high speed and the high axial load and causes the thermal expansion of element. In this research , the influence of different greases on ball screw is investigated in thermal rising of nut and driving torque in high speed and high axial load. A vertical motion platform was used for driving performance test. Thermal rising of nut of ball screw and the variance of transmission torque whose lubricated by high viscosity base oil grease is significant larger than the lower one. High viscosity grease is not easy to carry out the friction heat generated at ball and raceway contact area due to the bad flowing properties. It also has more serious wear occurred at contact area and high friction force, whose causes the large variance of transmission torque.

A New Shaft Coupling Design for a High-Speed Rotor Wheel

1995 ◽  
Author(s):  
Tibor Kiss ◽  
Wing-Fai Ng ◽  
Larry D. Mitchell
Keyword(s):  
High Speed ◽  
High Stress ◽  
Critical Issue ◽  
Working Environment ◽  
Outer Diameter ◽  
Stress Concentrations ◽  
Coupling Region ◽  
Rotor Wheel ◽  
High Stress Concentration ◽  
Safety Margins

Abstract A high-speed rotor wheel for a wind-tunnel experiment has been designed. The rotor wheel was similar to one in an axial turbine, except that slender bars replaced the blades. The main parameters of the rotor wheel were an outer diameter of 10“, a maximum rotational speed of 24,000 RPM and a maximum transferred torque of 64 lb-ft. Due to the working environment, the rotor had to be designed with high safety margins. The coupling of the rotor wheel with the shaft was found to be the most critical issue, because of the high stress concentration factors associated with the conventional coupling methods. The efforts to reduce the stress concentrations resulted in an advanced coupling design which is the main subject of the present paper. This new design was a special key coupling in which six dowel pins were used for keys. The key slots, now pin-grooves, were placed in bosses on the inner surface of the hub. The hub of the rotor wheel was relatively long, which allowed for applying the coupling near the end faces of the hub, that is, away from the highly loaded centerplane. The long hub resulted in low radial expansion in the coupling region. Therefore, solid contact between the shaft and the hub could be maintained for all working conditions. To develop and verify the design ideas, stress and deformation analyses were carried out using quasi-two-dimensional finite element models. An overall safety factor of 3.7 resulted. The rotor has been built and successfully accelerated over the design speed in a spin test pit.

scholarly journals Development of gear dynamic performance testing machine

2021 ◽  
Vol 12 ◽  
pp. 20
Author(s):  
Ke Li ◽  
Bo Yu ◽  
Zhaoyao Shi ◽  
Zanhui Shu ◽  
Rui Li
Keyword(s):  
High Speed ◽  
Performance Test ◽  
Dynamic Testing ◽  
Mechanical Design ◽  
Dynamic Performance ◽  
External Disturbance ◽  
Testing Machine ◽  
High Stress ◽  
Performance Testing ◽  
Current Application

With the development of gears towards high temperature, high pressure, high speed and high stress, gear measurement, in which only the static geometric accuracy is considered, is unable to meet the current application requirements. While, the low precision and single function gear tester constrains the measurement of gear dynamic performance. For the resolution of this problem, based on the principle of gear system dynamics and several precision mechanical design techniques, a gear dynamic testing machine has been developed, providing new instruments for gear testing. On the basis of research of the principle of dynamic performance test, the primary measurement items of the testing machine have been determined. The measuring principles of each item and the driving and loading form of the testing machine have been examined. The measurement and control system of the testing machine and its corresponding software have been developed. The instrument can not only obtain the static precision index of the gear, but also obtain the dynamic performance index of the gear in variable working conditions. According to the actual test, the uncertainty of instrument is 3.8 μm and the external disturbance caused by the shaft vibration is less than 0.6 μm, which can meet the 5–6 grade precision gear testing requirement.

Performance Analysis of Interconnects Based on Carbon Nanotubes for AMS/RF IC Design

2015 ◽  
pp. 336-363 ◽  
Author(s):  
Rafael Vargas-Bernal
Keyword(s):  
Carbon Nanotubes ◽  
Performance Analysis ◽  
Integrated Circuit ◽  
High Speed ◽  
Electrical Current ◽  
Essential Elements ◽  
Thermal Dissipation ◽  
Electrical Performance ◽  
Ic Design ◽  
Rf Ic

Electrical interconnects are essential elements to transmit electrical current and/or to apply electrical voltage to the electronic devices found in an integrated circuit. With the introduction of carbon nanotubes in electronic applications, efficient and high-speed interconnects have allowed for optimizing the electrical performance of the integrated circuits. Additionally, technical problems, such as electromigration, large values of parasitic elements, large delays, and high thermal dissipation, presented in metallic interconnects based on copper, can be avoided. This chapter presents a performance analysis of interconnects used in AMS/RF IC design based on carbon nanotubes as the physical material where electrical variables are provided.

Electrical Characterization on a High-Speed Wafer-Level Package

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 001937-001962
Author(s):  
Kai Liu ◽  
YongTaek Lee ◽  
HyunTai Kim ◽  
MaPhooPwint Hlaing ◽  
Susan Park ◽  
...  
Keyword(s):  
High Speed ◽  
Unit Length ◽  
Ground Plane ◽  
Measurement Data ◽  
Electrical Characterization ◽  
Electrical Performance ◽  
Metal Loss ◽  
Signal Loss ◽  
Wafer Level ◽  
Wafer Level Package

In this paper, a 2-layer eWLB (embedded Wafer-Level BGA) is studied and its performance is compared with an equivalent 4-layer laminate package. Since eWLB package is processed by using lithographical method, design rules on width (W) and spacing (S) are much finer (usually 2–3 times finer) than those for laminate package. In other words, signal traces can be implemented in smaller fan-out regions. The smaller feature sizes for signal traces would end up with more metal loss per unit length. But as the signal traces can be implemented in smaller fan-out regions, overall trace-routing may be shorter, and equivalent insertion-loss may be achieved. In eWLB, the ground plane is closer to the signal traces. This actually helps to reduce cross-talk between wide I/O buses, as the electrical field is contained in a smaller region by the closer ground plane. Another key advantage from wafer-level package is a smoother metal surface, which greatly reduces the extra signal loss, due to surface-roughness effect, especially for higher-frequency and higher-speed applications. In addition, through-via structures for wafer-level package are typically 2–3 times smaller. This allows to implement power/ground planes in a more continuous way, achieving better resistance and inductance for power/ground nets. Overall electrical performance, which takes into account of all the impacts above, can be evaluated by signal-integrity analysis (E-diagram). Measurement data of a 2-layer eWLB package for a LPDDR application will be presented, which shows the comparable performance typically obtained from a 4-layer laminate package

Design and Robustness of Quilt Packaging Superconnect

2012 ◽  
Vol 2012 (1) ◽  
pp. 000524-000530
Author(s):  
M. Ashraf Khan ◽  
Jason M. Kulick ◽  
Alfred M. Kriman ◽  
Gary H. Bernstein
Keyword(s):  
Thermal Cycling ◽  
High Speed ◽  
Low Cycle Fatigue ◽  
Simulation Models ◽  
Electrical Performance ◽  
Cycle Fatigue ◽  
Signal Delay ◽  
Thermal Reliability ◽  
Simulation Results ◽  
Quilt Packaging

Quilt Packaging (QP) is a novel high-speed superconnect (i.e. direct interchip interconnect), developed to improve electrical performance — signal delay, power loss, etc. Ultrahigh bandwidth has already been demonstrated for QP, but its unique structure requires thermal reliability issues to be studied. To this end, simulation models were developed to study the robustness of QP. QP structures were fabricated, and thermal cycling tests were performed focusing on the reliability for various shapes of nodules, the basic physical interconnect unit of QP. Simulations were performed to determine stress over a range of temperatures and estimate low cycle fatigue lifetimes. Simulations considered two types of solder and several adhesives. Thermal cycling experiments indicate that QP provides a robust structure, in agreement with the simulation results.

scholarly journals Fabrication of ZnO@Ag3PO4 Core-Shell Nanocomposite Arrays as Photoanodes and Their Photoelectric Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1254 ◽  
Author(s):  
Yi ◽  
Li ◽  
Wu ◽  
Chen ◽  
Yang ◽  
...  
Keyword(s):  
Performance Test ◽  
Structural Characteristics ◽  
Energy Dispersive Spectrometer ◽  
Zno Nanorods ◽  
Element Distribution ◽  
Core Shell ◽  
Photoelectric Properties ◽  
Component Test ◽  
Photoelectric Performance ◽  
Light Reflectance

In this study, we combine the methods of magnetron sputtering, hydrothermal growth, and stepwise deposition to prepare novel ZnO@Ag3PO4 core-shell nanocomposite arrays structure. Through scanning electron microscope (SEM) topography test, energy dispersive spectrometer (EDS) element test and X-ray diffractometry (XRD) component test, we characterize the morphology, element distribution and structural characteristics of ZnO@Ag3PO4 core-shell nanocomposite arrays structure. At the same time, we test the samples for light reflectance, hydrophilicity and photoelectric performance. We find that after deposition of Ag3PO4 on ZnO nanorods, light reflectance decreases. As the time of depositions increases, light reflectance gradually decreases. After the deposition of Ag3PO4, the surface of the sample shows super hydrophilicity, which is beneficial for the photoelectric performance test. Through the optical transient response test, we find that the photo-generated current reaches a maximum when a small amount of Ag3PO4 is deposited. As the time of depositions of Ag3PO4 increases, the photogenerated current gradually decreases. Finally, we conducted an alternating current (AC) impedance test and also verified the correctness of the photocurrent test. Therefore, the structure is expected to be prepared into a photoanode for use in fields such as solar cells.

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