Analysis of Magnetic Field in Dry-Reed Relay Application Circuit

2013 ◽  
Vol 787 ◽  
pp. 699-703
Author(s):  
Zhi Gui Lin ◽  
Xu Yang Wang ◽  
Zhao Lin ◽  
Wang Xi ◽  
Li Min
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Interference ◽  
Permutation Matrix ◽  
Experimental Result ◽  
Electric Polarity ◽  
Reed Relay ◽  
Polarity Alternation

To the problem of multiple dry-reed relays electromagnetic interference in application circuits, we present an effective method to reduce the electromagnetic interference in this paper. The method is alternating permutation matrix of dry-reed relays. The paper describes the cause of electromagnetic interference of dry-reed relays. Using the offset of electric polarity alternation principle, we put forward the method for reducing electromagnetic interference. The method is applied to a multi-functional physiotherapy instrument. By experiments, experimental result shows that the degree of electromagnetic interference is reduced along with the increase in the number of dry-reed relays.

A CMT Device for Electric Energy Meter Detection

2020 ◽  
Vol 13 ◽  
Author(s):  
Zhi Zeng ◽  
Yongfu Zhou
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Electromagnetic Interference ◽  
Production Efficiency ◽  
Electric Energy ◽  
Labor Cost ◽  
Automatic Testing ◽  
National Standard ◽  
Measurement Instruments ◽  
Detection Technology

Background: Detection technology is a product development technique that serves as a basis for quality assurance. As electric energy meters (EEMs) are measurement instruments whose use is mandatory in several nations, their accuracy, which directly depends on their reliability and proper functioning, is paramount. In this study, to eliminate electromagnetic interference, a device is developed for testing a set of EEMs under a constant magnetic field interference. The detection device can simultaneously test 6 electric meters; moreover, in the future, it will be able to measure the influence of magnetic field strength on the measurement accuracy of EEMs, thereby improving the production efficiency of electric meter manufacturers. Methods: In this study, we first design a 3D model of the detection device for a single meter component; then, we establish a network, which includes a control system, and perform the planning of the path of a block that generates a constant magnetic field. Finally, we control the three-axis motion and rotation of the block using a PLC to implement detection for the five sides of the EEM. Results & Discussion: The proposed device can accurately determine whether an EEM can adequately function, within the error range prescribed by a national standard, under electromagnetic interference; this can enable reliable, automatic testing and fault detection for EEMs. Experiments show that our device can decrease the labor cost for EEM manufacturers.

Multilayered Electromagnetic Interference Shielding Structures for Suppressing Magnetic Field Coupling

2018 ◽  
Vol 47 (9) ◽  
pp. 5243-5250 ◽  
Author(s):  
Atom O. Watanabe ◽  
Pulugurtha Markondeya Raj ◽  
Denny Wong ◽  
Ravi Mullapudi ◽  
Rao Tummala
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Interference ◽  
Electromagnetic Interference Shielding ◽  
Field Coupling ◽  
Magnetic Field Coupling

scholarly journals A Study on Common Mode Voltage Reduction Strategies According to Modulation Methods in Modular Multilevel Converter

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1607
Author(s):  
Chang-Hwan Park ◽  
In-Kyo Seo ◽  
Belete Belayneh Negesse ◽  
Jong-su Yoon ◽  
Jang-Mok Kim
Keyword(s):  
Electromagnetic Interference ◽  
Experimental Result ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Frequent Change ◽  
Common Mode ◽  
Medium Voltage ◽  
Low Level ◽  
Common Mode Voltage ◽  
Switching State

Low level modular multilevel converter (MMC) is a promising candidate for medium voltage applications such as MVDC (medium voltage DC current) transmission and megawatt machine drives. Unlike high-level MMC using nearest level modulation (NLM), the low-level MMC using the pulse width modulation (PWM) or NLM + PWM is affected by a common mode voltage (CMV) due to a frequent change of a switching state. This CMV causes electromagnetic interference (EMI) noise, common mode current (CMC) and bearing current leading to a reduction in the efficiency and durability of the motor drive system. Therefore, this paper provides a mathematical analysis on how the switching state affects the CMV and proposes three software based CMV reduction algorithms for the low level MMC system. To reflect the characteristic of MMC modulation strategy for upper and lower reference voltage independently, two separate space vectors are used. Based on the analysis, three different CMV reduction algorithms (complete CMV reduction (CCR), DPWM CMV reduction (DCR) and partial CMV reduction (PCR)) are proposed using NLC + PWM modulation strategy. The performance of the proposed CMV reduction algorithms was verified by both simulation and experimental result.

scholarly journals Analysis of the Influence of the Breaking Radiation Magnetic Field of a 10 kV Intelligent Circuit Breaker on an Electronic Transformer

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7800
Author(s):  
Wenchao Lu ◽  
Jiandong Duan ◽  
Lin Cheng ◽  
Jiangping Lu ◽  
Xiaotong Du
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Interference ◽  
Arc Discharge ◽  
Test System ◽  
Interference Signal ◽  
Processing Unit ◽  
Simulation Test ◽  
Electronic Transformer ◽  
Transient Electromagnetic ◽  
Intelligent Distribution

The development of the smart grid requires the distribution switch to not be limited to the original breaking function. More functional requirements lead to more complex switch structures, especially the intelligent processing unit on the secondary side. A technology called primary and secondary integration optimizes the structure of the switch, which greatly increases the intelligence level of the switch, but also has disadvantages. The secondary intelligent unit is arranged close to the primary high-voltage electromagnetic environment, and the distribution switch is prone to failure due to electromagnetic interference. In order to explore the influence of electromagnetic interference on it, a transient electromagnetic interference simulation test platform was built for a 10 kV intelligent distribution switch based on the principle of spherical gap arc discharge, and the interference signal of the intelligent distribution switch was measured; the law of the spatial magnetic field near the electronic transformer is mainly studied in this paper. The shielding effectiveness of the distribution terminal of the switch was analyzed, and the interference of the power line of the sensor merging unit circuit board was calculated. The results show that the electronic transformer may have serious faults under continuous strong transient electromagnetic interference. The electromagnetic transient simulation test system studied in this paper can evaluate the anti strong electromagnetic interference ability of the electronic transformer.

scholarly journals Design of Magnetic Coupler for Wireless Power Transfer

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 3000 ◽  
Author(s):  
Heqi Xu ◽  
Chunfang Wang ◽  
Dongwei Xia ◽  
Yunrui Liu
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Interference ◽  
Coupling Efficiency ◽  
Transmission Efficiency ◽  
Simulation Software ◽  
Good Effect ◽  
Wireless Charging ◽  
Magnetic Shield ◽  
Element Simulation ◽  
The Stability

In order to improve the restraint ability of electromagnetic energy in space and improve the coupling efficiency, a magnetic coupler structure with composite magnetic shield is proposed. Firstly, the model is established by using the finite-element simulation software. Then, according to the limit of public exposure to time-varying electromagnetic fields pointed out in ICNIPR (International Commission on Non-Ionizing Radiation Protection) guidelines, the characteristics and spatial magnetic field distribution of magnetic couplers with a single shielding structure, double shielding structure, and composite shielding structure are compared and analyzed. Finally, the experimental results show that the structure of magnetic couplers with a composite magnetic shield has a good effect in strengthening magnetic field concentration and reducing the electromagnetic interference of wireless charging systems to the external environment. It also has the advantages of smaller volume, lighter weight, and lower cost, and can effectively improve the transmission efficiency and enhance the stability of wireless charging systems.

Flux Pinning and Weak Link Structure in Ca2Cu1O3 Doped LnBa2Cu3O7-y (Ln=La and Y)

1989 ◽  
Vol 169 ◽  
Author(s):  
F. Mizuno ◽  
H. Masuda ◽  
I. Hirabayashi ◽  
S. Tanaka
Keyword(s):  
Magnetic Field ◽  
Flux Pinning ◽  
Magnetic Field Dependence ◽  
Weak Link ◽  
Impurity Phase ◽  
Experimental Result ◽  
Ca Doping ◽  
Link Structure ◽  
Pinning Center ◽  
The Magnetic Field

AbstractFlux pinning and weak link structure were studied on the effect of Ca doping in LnBa2Cu3O7-y system (Ln=La and Y). The magnitude and the magnetic field dependence of the critical current density were improved by Ca doping. A small amount of impurity phase of such as Ca2Cu1O3 may work as a desirable flux pinning center. Moreover, it was found that the current-temperature characteristics for Ca-doped samples showed the evidence of two kinds of superconducting phases which have different transition temperature Tc and Tc'. The experimental result agrees well with the Ambegaokar-Baratoff theory for asymmetric Josephson junctions (S-I-S') in the temperature range of T < Tc' and with the proximity junction theory (S-N-S) in the range of Tc'<T<Tc.

An Innovative Way to Measure Temperature by Using the Faraday Effect

2011 ◽  
Author(s):  
Pranav Limaye ◽  
Anisur Rehman
Keyword(s):  
Magnetic Field ◽  
Optical Sensors ◽  
Electromagnetic Interference ◽  
Temperature Sensor ◽  
Faraday Effect ◽  
Fiber Optic ◽  
Magnetic Field Intensity ◽  
Sensing Element ◽  
Fiber Optic Cable ◽  
Optical Phenomenon

An innovative temperature sensor has been presented based on “Faraday Effect”. The Faraday Effect or the Faraday rotation is a magneto-optical phenomenon; that is, an interaction between electromagnetic wave and a magnetic field in a medium. Optical sensors based on the Faraday Effect have the advantages of simplicity, high electrical insulation and immunity to electromagnetic interference. We will be making use of an optical fiber and a permanent magnet as our sensing elements. The magnet will be the sensing element for change in temperature and the fiber optic cable will sense the change in magnetic field intensity corresponding to the change in temperature.

Experimental and Numerical Investigation of Melting in the Presence of a Magnetic Field: Simulation of Low Gravity Environment

2005 ◽  
Author(s):  
H. Zhang ◽  
H. Sun ◽  
M. Charmchi ◽  
D. Veilleux ◽  
M. Faghri
Keyword(s):  
Magnetic Field ◽  
Numerical Study ◽  
Melting Behavior ◽  
Transverse Magnetic ◽  
Melting Rate ◽  
Experimental Result ◽  
Working Fluid ◽  
Convection Flow ◽  
Remarkable Effect ◽  
Magnetic Strength

An experimental and numerical study is presented on melting behavior of a pure metal in the presence of a static magnetic field. When a transverse magnetic field is present and the working fluid is electrically conductive, the resulting Lorentz forces will dampen the convective flows. Buoyancy driven flow is the focus of this study. Hartmann number, a dimensionless parameter proportional to the strength of magnetic field, dominates the convection flow suppression. The effects of the magnetic strength on melting rate and on the profile of solid/melt interface are studied. The experiments are conducted with pure Gallium as phase change material (PCM) inside a rectangular test cell. The solid/melt interface at the side center position is measured by an ultrasound device and its profile is mapped via the florescent light shadowgraphy. Temperature measurements and volume expansion/contraction tracking are used to verify the experimental result. The results show that the magnetic strength has a remarkable effect on the melting rate and the interface profile. The numerical simulation fits very well with the experimental data especially, at larger Hartmann numbers.

scholarly journals Design and Study of a Wide-Band Printed Circuit Board Near-Field Probe

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2201 ◽  
Author(s):  
Pedro A. Martinez ◽  
Enrique A. Navarro ◽  
Jorge Victoria ◽  
Adrian Suarez ◽  
Jose Torres ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Interference ◽  
Printed Circuit Board ◽  
Transmission Loss ◽  
Near Field ◽  
Fem Simulation ◽  
Numerical Results ◽  
Circuit Board ◽  
Frequency Range ◽  
Printed Circuit

Magnetic near-field probes (NFP) represent a suitable tool to measure the magnetic field level from a small electromagnetic interference (EMI) source. This kind of antenna is useful as a magnetic field probe for pre-compliance EMC measurements or debugging tasks since the user can scan a printed circuit board (PCB) looking for locations with strong magnetic fields. When a strong H-field point is found, the designer should check the PCB layout and components placement in that area to detect if this could result in an EMI source. This contribution focuses on analyzing the performance of an easy to build and low-cost H-field NFP designed and manufactured using a standard PCB stack-up. Thereby, the frequency range and sensitivity of the NFP-PCB are analyzed through a Finite Element Method (FEM) simulation model that makes it possible to evaluate its sensibility and effective frequency range. The numerical results obtained with the FEM models are validated against measurements to verify the design and performance of our NFP. The FEM model reproduces the experimental procedure, which is used to evaluate the performance of the NFP in terms of sensitivity by means of the simulated near-field distribution. The NFP-PCB has almost a flat response from 180 MHz to 6 GHz, with an almost perfect concordance between numerical and experimental S21 results. The numerical results show an average transmission loss of −27.9 dB by considering the flat response bandwidth, whereas the experimental one is −29.7 dB. Finally, the designed NFP is compared to two high-quality commercial probes in order to analyze its performance.

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