Characteristic Analysis and Measurement of Dielectric Loss in Non-Linear Insulating Materials

2014 ◽  
Vol 986-987 ◽  
pp. 1471-1476
Author(s):  
Rong Xia

Non-linear insulating material is widely used in the insulations of XLPE cable terminations and stator windings insulation of electric machines, and has obvious capability to improve the distribution of electric field. Actually, the dielectric loss factor of non-linear insulating materials is not equal to the tanδ describing linear insulating materials, and depends on applied voltage and their structures. This paper firstly discusses the difference between ac loss characteristic of non-linear dielectrics and linear dielectrics and presents a kind model of non-linear composite material. Based on the model, specific characterization and measurement methods and their numeric simulation analysis are given. Finally, a measuring system for non-linear insulating materials based on digital measuring technology is presented.

2012 ◽  
Vol 271-272 ◽  
pp. 1742-1749
Author(s):  
Peng Cheng Huang ◽  
Qing Hua Yang ◽  
Guan Jun Bao ◽  
Li Bin Zhang

Aimed at existing problems on the bending performance of pneumatic bending joint, a new type of pneumatic bending joint is proposed in this paper. Double flexible pneumatic actuators are used as actuating drivers. Based on the first law of thermodynamics and the joint dynamic equation, the angle dynamic model is established and analyzed. Moreover simplified model is proposed. Meanwhile, its dynamic characteristic is analyzed through simulation analysis. The simulation suggests the following results: in the gas-filled phase, the joint’s pressure response time is about 10ms; while it is about 60ms in the gas-escape phase; and the angle response time of joint is 10 to 20ms. When the joint damping coefficient is increasing, this value will also increase.


Author(s):  
James Flinders ◽  
John D. Clemens

ABSTRACT:Most natural systems display non-linear dynamic behaviour. This should be true for magma mingling and mixing processes, which may be chaotic. The equations that most nearly represent how a chaotic natural system behaves are insoluble, so modelling involves linearisation. The difference between the solution of the linearised and ‘true’ equation is assumed to be small because the discarded terms are assumed to be unimportant. This may be very misleading because the importance of such terms is both unknown and unknowable. Linearised equations are generally poor descriptors of nature and are incapable of either predicting or retrodicting the evolution of most natural systems. Viewed in two dimensions, the mixing of two or more visually contrasting fluids produces patterns by folding and stretching. This increases the interfacial area and reduces striation thickness. This provides visual analogues of the deterministic chaos within a dynamic magma system, in which an enclave magma is mingling and mixing with a host magma. Here, two initially adjacent enclave blobs may be driven arbitrarily and exponentially far apart, while undergoing independent (and possibly dissimilar) changes in their composition. Examples are given of the wildly different morphologies, chemical characteristics and Nd isotope systematics of microgranitoid enclaves within individual felsic magmas, and it is concluded that these contrasts represent different stages in the temporal evolution of a complex magma system driven by nonlinear dynamics. If this is true, there are major implications for the interpretation of the parts played by enclaves in the genesis and evolution of granitoid magmas.


2004 ◽  
Vol 833 ◽  
Author(s):  
Nadia K. Pervez ◽  
Jiwei Lu ◽  
Susanne Stemmer ◽  
Robert A. York

ABSTRACTIn universal relaxation, a material's complex dielectric susceptibility follows a fractional power law f1-n where 0 < n < 1 over multiple decades of frequency. In a variety of materials, including Ba0.5Sr0.5Ti03, dielectric relaxation has been observed to follow this universal relaxation model with values of n close to 1. In this work we have shown that the universal relaxation model can be used to calculate dielectric loss even when n is very close to 1. Our calculated Q-factors agree with measured values at 1 MHz; this agreement suggests that this technique may be used for higher frequencies where network analyzer measurements and electrode parasitics complicate Q-factor determination.


Cryogenics ◽  
2021 ◽  
Vol 113 ◽  
pp. 103234
Author(s):  
Mohammad Yazdani-Asrami ◽  
S. Asghar Gholamian ◽  
Seyyed Mehdi Mirimani ◽  
Jafar Adabi

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5847
Author(s):  
Xiaohao Li ◽  
Junqi Pan ◽  
Xingchen Zhou

In order to meet the increasing application requirements with regards to structural impact resistance in industries such as mining, construction, aerospace engineering, and disaster relief and mitigation, this paper designs a variant truss beam structure with a large shrinkage ratio and high impact resistance. Based on the principle of the curved trajectory of scissor mechanisms, this paper conducts a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. In the paper, the buffer effect of the external load impact on the variant truss beam structure is analyzed from the perspective of the energy change of elastic–plastic deformation. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. The strategy provides a feasible method with which to verify the effectiveness and impact resistance of a variant truss structure design.


2019 ◽  
Vol 5 (1) ◽  
pp. 85
Author(s):  
Ramdhan Taufik ◽  
Erma Desmaliana ◽  
Amatulhay Pribadi

ABSTRAKKondisi geografis Indonesia memiliki struktur tektonik kompleks. Kondisi ini membuat perencanaan rumah tinggal 2 (dua) lantai membutuhkan pertimbangan khusus dari segi kekuatan dan kekakuan. Penggunaan material kayu sebagai bahan konstruksi di Indonesia masih jarang digunakan. Kayu glulam adalah suatu produk kayu rekayasa yang dibuat dari beberapa bilah kayu yang direkatkan dengan arah sejajar serat menggunakan perekat berupa lem. Penelitian ini bertujuan untuk mengidentifikasi respon struktur pada rumah tinggal menggunakan material kayu glulam dan solid dengan bantuan program ETABS 2016. Berdasarkan analisis yang telah dilakukan, diperoleh nilai periode struktur, gaya geser dasar, dan simpangan antar lantai antara seluruh model menunjukan hasil yang berbeda, perbedaan diakibatkan dari hasil konversi berat jenis dan modulus of elastisity berdasarkan BS EN 1194:1999. Berdasarkan analisis non-linier pushover didapatkan bahwa kayu glulam Nyatoh (kayu kelas III) berada pada level pada kinerja B to IO (Immediate Occupancy), dimana hasil tersebut tidak berbeda jauh dengan kayu solid Bangkirai (kayu kelas I).Kata Kunci: rumah tinggal, kayu glulam, non-linier pushover ABSTRACTGeographical condition of Indonesia has a complex tectonic structure. These conditions create  2-storyhome-planning that require special consideration in terms of strength and rigidity. The use of wood as a construction material in Indonesia is still rarely used. Glulam wood is a wood products engineering made from wooden slats several glued with the direction of the parallel fibers using adhesives. This research aims to identify the structure of the response at home using basic material glulam and solid wood with the help of ETABS 2016 programs. Based on the analysis that has been done, obtained the value of the structure periode, base shear force, and interstory drift between all models show different results, the difference is due to the results of specific gravity conversion and modulus of elasticity base on BS EN 1194:1999. Based on non-linear pushover analysis, it shows that Nyatoh glulam wood (class III wood) was at the level of the B to IO (Immediate Occupancy) performance, where the results were not much different from Bangkirai solid wood (class I wood).Keywords: home livingstructure, glulam wood, non-linear pushover


Author(s):  
Youcef Saidi ◽  
Abdelkader Mezouar ◽  
Yahia Miloud ◽  
Mohammed Amine Benmahdjoub ◽  
Brahim Brahmi ◽  
...  

In this paper, modeling, and speed/position sensor-less designed Direct Voltage Control (DVC) approach based on the Lyapunov function are studied for three-phase voltage source Space Vector Pulse Width Modulation (SVPWM) Rectifier Connected to a Permanent Magnet Synchronous Generator (PMSG) Variable Speed Wind Power Generation System (VS-WPGS). This control strategy is based on voltage orientation technique without mechanical speed sensor. Advanced Non-linear Integral Backstepping Control (IBSC) of the Generator Side Converter (GSC) has the ability to have a good regulation of the DC link voltage to meet the requirements necessary to achieve optimal system operation, regardless of the disturbances caused by the characteristics of the drive train or some changes into the DC load. The estimation of the speed is based on Model Reference Adaptive System (MRAS) method. This method consists in developing two models one of reference and the other adjustable for the estimation of the two d-q axis components of the stator flux from the measurement of currents, the speed estimated is obtained by canceling the difference between the reference stator flux and the adjustable one using Lyapunov criterion of hyper-stability. Some results of simulation using Matlab/Simulink® are presented, discussed to prove the efficiency and robustness of the system control policy for WPGS against external and internal perturbations.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Sahar Ghanipoor Machiani ◽  
Alidad Ahmadi ◽  
Walter Musial ◽  
Anagha Katthe ◽  
Benjamin Melendez ◽  
...  

The main objective of this study is to evaluate the safety and operational impacts of an innovative infrastructure solution for safe and efficient integration of Automated Vehicle (AV) as an emerging technology into an existing transportation system. Filling the gap in the limited research on the effect of AV technology on infrastructure standards, this study investigates implications of adding a narrow reversible AV-exclusive lane to the existing configuration of I-15 expressway in San Diego, resulting in a 9 ft AV reversible lane and, in both directions, two 12-feet lanes for HOV and FasTrak vehicles. Given the difference between the operation of AVs and human-driven vehicles and reliance of AVs on sensors as opposed to human capabilities, the question is should we provide narrower AV-exclusive roadways assuming AVs are more precise in lateral and longitudinal lane keeping behaviour? To accomplish the goal of the project, a historical crash data analysis and a traffic simulation analysis were conducted. Crash data analysis revealed that unsafe speed, improper turning, and unsafe lane change are the most recurring primary collision factors on I-15 ELs. AVs’ automated longitudinal and lateral control systems could potentially reduce these types of collisions on an AV-exclusive lane with proper infrastructure features for AV sensor operation (e.g., distinct lane marking). Microsimulation findings indicated an AV-exclusive lane may increase traffic flow and density by up to 14% and 24%, respectively. It also showed that average speed is reduced. However, this could lead to the speed differential increase between the exclusive lane and adjacent lane requiring careful consideration if additional treatments or barriers are needed. The results of this study contribute to infrastructure adaptation to AV technology and future AV-exclusive lanes implementations.


1995 ◽  
Vol 04 (04) ◽  
pp. 489-500 ◽  
Author(s):  
NAOHIRO ISHII ◽  
KEN-ICHI NAKA

Asymmetrical neural networks are shown in the biological neural network as the catfish retina. Horizontal and bipolar cell responses are linearly related to the input modulation of light, while amacrine cells work linearly and nonlinearly in their responses. These cells make asymmetrical neural networks in the retina. Several mechanisms have been proposed for the detection of motion in biological system. To make clear the difference among asymmetrical networks, we applied non-linear analysis developed by N. Wiener. Then, we can derive α-equation of movement, which shows the direction of movement. During the movement, we also can derive the movement equation, which implies that the movement holds regardless of the parameter α. By analyzing the biological asymmetric neural networks, it is shown that the asymmetric networks are excellent in the ability of spatial information processing on the retinal level. Then, the symmetric network was discussed by applying the non-linear analysis. In the symmetric neural network, it was suggested that memory function is needed to perceive the movement.


Sign in / Sign up

Export Citation Format

Share Document