scholarly journals Optical Fiber Current Sensors Based on FBG and Magnetostrictive Composite Materials

2020 ◽  
Vol 11 (1) ◽  
pp. 161
Author(s):  
Shaoyi Xu ◽  
Qiang Peng ◽  
Chuansheng Li ◽  
Bo Liang ◽  
Junwen Sun ◽  
...  
Keyword(s):  
Composite Materials ◽  
Optical Fiber ◽  
Electromagnetic Interference ◽  
Dynamic Range ◽  
High Reliability ◽  
Magnetostrictive Material ◽  
Magnetostrictive Materials ◽  
Giant Magnetostrictive Material ◽  
Giant Magnetostrictive Materials ◽  
Current Sensors

Optical fiber current sensors are widely used in the online monitoring of a new generation power system because of their high electrical insulation, wide dynamic range, and strong anti-electromagnetic interference ability. Current sensors, based on fiber Bragg grating (FBG) and giant magnetostrictive material, have the advantages of high reliability of FBG and high magnetostrictive coefficient of giant magnetostrictive material, which can meet the monitoring requirements of digital power systems. However, giant magnetostrictive materials are expensive, fragile, and difficult to mold, so giant magnetostrictive composite materials have replaced giant magnetostrictive materials as the sensitive elements of sensors. High sensitivity, high precision, wide working range, low response time, and low-cost optical fiber current sensors based on magnetostrictive composites have become a research hotspot. In this paper, the working principle of the sensor, the structure of the sensor, and the improvement of magnetostrictive composite materials are mainly discussed. At the same time, this paper points out improvements for the sensor.

Spectrum Absorption Methane Gas Sensor with Optical Fiber Based on Frequency Harmonic Detection Mechanism

2011 ◽  
Vol 383-390 ◽  
pp. 2907-2911
Author(s):  
Jiu Long Wang
Keyword(s):  
Optical Fiber ◽  
Light Source ◽  
Electromagnetic Interference ◽  
Near Infrared ◽  
Dynamic Range ◽  
Second Harmonic ◽  
High Sensitivity ◽  
Detection Mechanism ◽  
Methane Gas ◽  
Safe Production

Methane is an easily burning and exploding gas. It is the primary component of many gas fuels such as mine gas and natural gas and so on. In the coal mine accidences of our country, the casualties caused by gas explosion covers over 50% in all great casualties, and it becomes the largest obstruction of safe production. Incident online detecting methane gas density has important significance for mine and plant safe production and personal safety. Based on the near infrared spectral absorption of methane, a system using absorption type optical fiber for high sensitivity methane detection is demonstrated in this paper. DFB LD is adopted as light source in this paper. Modulating the light source, methane gas is detected by second harmonic. The ratio of the fundamental and second harmonic signal can be used for eliminating the interference owing to light power changing. The mathematical model of gas concentration harmonic measurement is built up. The result of methane concentration is also shown. The system overcomes the defect of great interference of available instruments by light route. It has advantages such as high sensitivity, quick response speed, large dynamic range, preventing electromagnetic interference, preventing burning and explosion, not easily being poisoned and so on. The probe can be put in condition of easily burning and exploding, being poisonous being high temperature and so on that man and instrument can not easily enter. It can realize online continuous telecontrol and telemeter.

Analysis of Dynamic Characteristics of the Magnetostrictive Power Ultrasonic Transducer

2011 ◽  
Vol 105-107 ◽  
pp. 1693-1696
Author(s):  
Geng Xin Zeng ◽  
Biao Cao ◽  
Hai Quan Zeng
Keyword(s):  
Dynamic Characteristics ◽  
Ultrasonic Transducer ◽  
Steady State Solution ◽  
Magnetostrictive Material ◽  
Giant Magnetostrictive Material ◽  
Giant Magnetostrictive Materials ◽  
Power Ultrasonic ◽  
External Conditions ◽  
Working Principle ◽  
Computer Imitation

The giant magnetostrictive material (GMM) is a novel smart material based on magnetostrictive effect, and it is well suited to power ultrasonic transducer. Based on electromagnetic theory and vibration theory, the design and working principle of the magnetostrictive power ultrasonic transducer has been explained. This paper analyzed the dynamic characteristics of giant magnetostrictive materials under the outside magnetic field and deduced the wave equation of Terfenol-D rod, and the steady-state solution to the equation was obtained under given excitation. The speed and acceleration expressions of Terfenol-D were deduced by differentiating with respect to displacement equation. Based on developing mathematical models, computer imitation was made, and the result of modulation was analyzed from external conditions of transducer and inner structure of magnetostrictive material.

scholarly journals Construction and Numerical Realization of a Magnetization Model for a Magnetostrictive Actuator Based on a Free Energy Hysteresis Model

2019 ◽  
Vol 9 (18) ◽  
pp. 3691
Author(s):  
Zhen Yu ◽  
Chen-yang Zhang ◽  
Jing-xian Yu ◽  
Zhang Dang ◽  
Min Zhou
Keyword(s):  
Free Energy ◽  
High Reliability ◽  
Large Strain ◽  
Mechanical Strain ◽  
Engineering Application ◽  
Numerical Realization ◽  
Hysteresis Model ◽  
Magnetostrictive Material ◽  
Giant Magnetostrictive Material ◽  
Magnetostrictive Actuators

Giant magnetostrictive actuators (GMA) driven by giant magnetostrictive material (GMM) has some advantages such as a large strain, high precision, large driving force, fast response, high reliability, and so on, and it has become the research hotspot in the field of microdrives. Research shows there is a nonlinear, intrinsic relationship between the output signal and the input signal of giant magnetostrictive actuators because of the strong coupling characteristics between the machine, electromagnetic field, and heat. It is very complicated to construct its nonlinear eigenmodel, and it is the basis of the practical process of giant magnetostrictive material to construct its nonlinear eigenmodel. Aiming at the design of giant magnetostrictive actuators, the magnetization model based on a free-energy hysteresis model has been deeply researched, constructed, and put forward by Smith, which combines Helmholtz–Gibbs free energy and statistical distribution theory, to simulate the hysteresis model at medium or high driving strengths. Its main input and output parameters include magnetic field strength, magnetization, and mechanical strain. Then, numerical realization and verification of the magnetization model are done by the Gauss–Legendre integral discretization method. The results show that the magnetization model and its numerical method are correct, and the research results provide a theoretical basis for the engineering application of giant magnetostrictive material and optimized structure of giant magnetostrictive material actuators, which have an important practical application value.

scholarly journals Nonlinear Companding Circuits With Thermal Compensation to Enhance Input Dynamic Range in Analog Optical Fiber Links

2011 ◽  
Vol 9 (01) ◽  
Author(s):  
J. Rodríguez-Rodriguez ◽  
J. Velazquez-Hernández
Keyword(s):  
Optical Fiber ◽  
Electromagnetic Interference ◽  
Dynamic Range ◽  
Measuring System ◽  
Transient Signal ◽  
Thermal Drift ◽  
Thermal Compensation ◽  
Voltage Range ◽  
Nonlinear Compensation ◽  
Fiber Links

Measuring systems based on a pair of optical fiber transmitter-receivers are used in medium-voltage testing laboratories wherein the environment of high electromagnetic interference (EMI) is a limitation for using conventional cabling. Nonlinear compensation techniques have been used to limit the voltage range at the input of optical fiber links. However, nonlinear compensation introduces gain and linearity errors caused by thermal drift. This paper presents a method of thermal compensation for the nonlinear circuit used to improve transient signal handling capabilities in measuring system while maintaining low errors in gain and linearity caused by thermal drift.

Design and Experimental Study of the Vibration Control Device for Large Spatial Structure

2011 ◽  
Vol 199-200 ◽  
pp. 1435-1440
Author(s):  
She Liang Wang ◽  
Jian Bo Dai ◽  
Xiang Zhao ◽  
Lu Lu Miao
Keyword(s):  
Spatial Structure ◽  
Vibration Control ◽  
High Efficiency ◽  
High Reliability ◽  
Mechanical Energy ◽  
Control Device ◽  
Driving Voltage ◽  
Force Output ◽  
Magnetostrictive Material ◽  
Giant Magnetostrictive Material

According to active vibration control of the large spatial structure, a vibration control device called giant magnetostrictive material actuator was designed which could convert electromagnetic energy into mechanical energy. This device take giant magnetostrictive material as the core component and make full use of its magnetic properties like big force output, fast response, high reliability and low driving voltage. Then its principle and design method was analyzed, and output performance tests were done. The results show that this device have good magnetic circuit structure, high efficiency of energy conversion, and could output larger force and displacement under the drive current with linear relationship sensitively, and lay a good foundation for its application in the large spatial structure.

Recent progress on carbon-based composite materials for microwave electromagnetic interference shielding

Carbon ◽  
2021 ◽  
Vol 177 ◽  
pp. 304-331
Author(s):  
Rajesh Kumar ◽  
Sumanta Sahoo ◽  
Ednan Joanni ◽  
Rajesh K. Singh ◽  
Wai Kian Tan ◽  
...  
Keyword(s):  
Composite Materials ◽  
Electromagnetic Interference ◽  
Recent Progress ◽  
Electromagnetic Interference Shielding ◽  
Carbon Based

scholarly journals In-Process Diameter Measurement Technique for Micro-Optical Fiber with Standing Wave Illumination

2021 ◽  
Author(s):  
Masaki Michihata ◽  
Zhao Zheng ◽  
Daiki Funaiwa ◽  
Sojiro Murakami ◽  
Shotaro Kadoya ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Standing Wave ◽  
Dynamic Range ◽  
Scattered Light ◽  
High Dynamic Range ◽  
Measurement Range ◽  
Diameter Distribution ◽  
Process Measurement ◽  
Air Turbulence ◽  
Tapered Optical Fiber

AbstractIn this paper, we propose an in-process measurement method of the diameter of micro-optical fiber such as a tapered optical fiber. The proposed technique is based on analyzing optically scattered light generated by standing wave illumination. The proposed method is significant in that it requires an only limited measurement range and does not require a high dynamic range sensor. These properties are suitable for in-process measurement. This experiment verified that the proposed method could measure a fiber diameter as stable as ± 0.01 μm under an air turbulence environment. As a result of comparing the measured diameter distribution with those by scanning electron microscopy, it was confirmed that the proposed method has a measurement accuracy better than several hundred nanometers.

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