MMC Modeling and Internal Electromagnetic Interference Mechanism Analysis

Abstract With the development of high-speed railway and heavy-haul rail transport in China, a large number of new types of electric locomotives and electric multiple units have been put into operation, improving the efficiency and equipment quality of railway transportation. However, harmonics emitted from the traction system and locomotives often interfere with the railway signalling equipment, which can lead to critical malfunction of the equipment. Based on field test data, this paper analyses the interference coupling mechanism and magnitude of traction harmonics to the signalling equipment using a three-element method of interference. It examines the three essential elements of electromagnetic interference, studies harmonic mitigation measures and proposes to solve the problem of inteference with signalling equipment by installing a passive high-pass filter in the coupling path. After comparing the effects of several types of filters using simulation tests, this paper verified the validity of the method and concluded that a second-order passive filter is the optimal solution for harmonic interference mitigation.

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Search on Ignition Interference Prevention of Vehicle Safety System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.6123 ◽

2014 ◽

Vol 556-562 ◽

pp. 6123-6127

Author(s):

Wei Zhou ◽

Shi Shun Dai ◽

Xuan Dong ◽

Chun Xiao Ren

Keyword(s):

Software Design ◽

Electromagnetic Interference ◽

Safety System ◽

Vehicle Safety ◽

Prevention Measures ◽

Electromagnetic Environment ◽

Simulation Experiments ◽

The Stability ◽

The Moment ◽

Interference Mechanism

Basic on the problem that the electromagnetic environment in vehicles which formed at the moment of ignition will cause interference to the stability and reliability of vehicle safety system, the paper takes vehicle fire protection system as the research object, and analyzes the interference mechanism and harmfulness through the simulation experiments. Finally uses the related software design and some prevention measures for electromagnetic interference such as shielding, grounding to protect the system, then through experiment to verify that it’s scientific and reasonable.

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Research on Continuous Wave Electromagnetic Effect in Swept Frequency Radar

Mathematical Problems in Engineering ◽

10.1155/2021/4862451 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Xue Du ◽

Guanghui Wei ◽

Hongze Zhao ◽

Xiaodong Pan

Keyword(s):

Field Strength ◽

False Alarm ◽

Electromagnetic Interference ◽

Continuous Wave ◽

Single Frequency ◽

Electromagnetic Effect ◽

Interference Field ◽

Electromagnetic Environment ◽

Front End ◽

Interference Mechanism

In order to establish the prediction model of radar equipment in multisource complex electromagnetic environment, the blocking effect and false alarm interference effect caused by single-frequency CW (continuous wave) electromagnetic interference on typical radar equipment are studied. Taking a certain sweep radar as the research object, the equivalent injection test of EMI (electromagnetic interference) is carried out. Based on the theory of radar front door coupling, the interference mechanism of EMI to radar receiver RF front end is revealed, and the variation law of blocking target and false alarm target level is analyzed. The results show that, under the single-frequency CW-EMI, the target echo level decreases with the increase of the interference field strength, and the false alarm level increases with the increase of the interference field strength. The blocking jamming sensitive bandwidth is about f 0 ± 200 MHz , and the false alarm jamming sensitive bandwidth is about f 0 ± 80 MHz .

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High-voltage monitoring by the fiber-optic recirculating measuring system

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-2-38-44 ◽

2020 ◽

pp. 38-44

Author(s):

A. V. Polyakov ◽

M. A. Ksenofontov

Keyword(s):

Optical Fibers ◽

High Voltage ◽

Optical Sensors ◽

Electromagnetic Interference ◽

Fiber Optic ◽

Electric Power Industry ◽

Measuring System ◽

Voltage Range ◽

External Electromagnetic Fields ◽

Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

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