scholarly journals Karakterisasi Conducted Emission Noise pada Inverter di Sistem Photovoltaic Off-Grid

2021 ◽  
Vol 10 (1) ◽  
pp. 100-109
Author(s):  
Yudhistira ◽  
Dwi Mandaris ◽  
Yoppy ◽  
Hutomo Wahyu Nugroho ◽  
Prayoga Bakti ◽  
...  
Keyword(s):  
Noise Level ◽  
Sine Wave ◽  
Conducted Emission ◽  
Cispr 25

Gangguan elektromagnetik berupa conducted emission noise yang ditimbulkan oleh inverter pada sistem photovoltaic (PV) off-grid telah berhasil dikarakterisasi. Noise yang merambat pada jalur konduksi dihasilkan dari fenomena switching inverter untuk proses konversi daya dari listrik searah (DC) menjadi arus bolak balik (AC). Standar IEC 62920:2017 dan CISPR 25:2016 digunakan untuk mengukur noise yang dihasilkan oleh inverter di sisi DC. Pengukuran conducted emission noise pada inverter dilakukan dalam tiga kondisi, yakni kondisi tanpa beban, terhubung dengan beban lampu pijar 60 W, dan terhubung dengan beban lampu pijar beserta dimmer untuk variasi daya. Pengukuran dilakukan pada lima buah inverter dengan kapasitas daya dan jenis keluaran (output) yang berbeda-beda, yaitu 200 W, 300 W, dan 700 W untuk tegangan keluaran modified sine wave serta 500 W dan 1.000 W untuk tegangan keluaran pure sine wave. Hasil pengukuran menunjukkan bahwa pada kondisi inverter terhubung dengan beban lampu pijar beserta dimmer, inverter model pure sine wave 500 W dan 1.000 W memiliki peak noise level yang cukup rendah dan berpotensi lebih sedikit untuk menimbulkan gangguan elektromagnetik di sisi DC.

Electromagnetic Interference Testing and Suppression Methods for Automotive Window Lifter Motor

2013 ◽  
Vol 433-435 ◽  
pp. 940-944
Author(s):  
Qun Hou ◽  
Ya Ping Jin ◽  
Yi Fan Zhou
Keyword(s):  
Electromagnetic Interference ◽  
Generation Mechanism ◽  
Conducted Emission ◽  
Cispr 25 ◽  
Radiated Emission

Window lifter motor is one of the potential electromagnetic interference (EMI) sources in automobile. Based on the research on the principle of Window lifter motor and the generation mechanism of EMI, its EMI characteristics are tested and analyzed. The EMI suppression methods are proposed. By comparing two filters methods,it shows that the designed filter suppresses the electromagnetic interference more effectively. Its conducted emission and radiated emission are lower than the second lever limits of CISPR 25-2007+.

scholarly journals Specifying Power Filter Insertion Loss Values in Terms of Electromagnetic Safety of IT Equipment

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 2041
Author(s):  
Leszek Nowosielski ◽  
Bartosz Dudziński ◽  
Rafał Przesmycki ◽  
Marek Bugaj
Keyword(s):  
Insertion Loss ◽  
Noise Level ◽  
Information Leakage ◽  
Environmental Noise ◽  
Analytical Relation ◽  
Power Filter ◽  
Conducted Emission ◽  
System Input ◽  
Filter Insertion

At present, one of the main methods of minimizing risk resulting from electromagnetic information leakage is to attenuate the undesired levels of radiated and conducted disturbances generated by IT equipment, as these disturbances can carry information processed by said equipment. Attenuation of conducted compromising emissions is most commonly handled with filters with a sufficiently high insertion loss. This article defines an original analytical relation specifying insertion loss value requirements for mains filters and estimates values of parameters included in the defined relation. Furthermore, this defined relation was used to define requirements for insertion loss provided by the mains filters, above which the ratio value of potentially compromising conducted emission levels to the environmental noise level at the infiltrating system input S/N < 0 dB. As a consequence, electromagnetic infiltration is significantly impeded.

Practical Simulation Methods Considering Characteristic Variations of Wires for CISPR 25 Conducted Emission

2021 ◽  
Author(s):  
H. Sugo ◽  
Y. Sarai ◽  
B. P. Nayak ◽  
H. Muniganti ◽  
D. Gope ◽  
...  
Keyword(s):  
Simulation Methods ◽  
Conducted Emission ◽  
Cispr 25

Effects of ground connections on CISPR 25 conducted emission test

2012 ◽  
Author(s):  
Hyun Gwi Hong ◽  
Beom Jin Choi ◽  
Eun Ha Kim ◽  
Seung Real Ryu ◽  
Jae Hyun Lee
Keyword(s):  
Conducted Emission ◽  
Cispr 25

POLARITY COINCIDENCE SCHEME FOR REVEALING SIGNAL COHERENCE

Geophysics ◽  
1957 ◽  
Vol 22 (3) ◽  
pp. 553-564 ◽  
Author(s):  
Ben S. Melton ◽  
Philip R. Karr
Keyword(s):  
Noise Level ◽  
Sine Wave ◽  
Statistical Procedure ◽  
Electrical System ◽  
Wave Signal

A simple statistical procedure, based on multiple coincidence of field polarities as indicated by several receptors, offers a criterion of the existence of a signal below the general noise level. As an example, with six receptors in a field where there is a sine wave signal ten decibels below the noise level, there will be twice the number of coincidences that would be obtained for the noise alone. A scheme is shown to illustrate how an electrical system can perform the analysis and present the results continuously.

Study on EMI Reduction of DC-DC Buck Converter

2014 ◽  
Vol 893 ◽  
pp. 742-746
Author(s):  
Long Huang ◽  
Fang Ping Yu ◽  
Tai Long Liu ◽  
Peng Li ◽  
Qi Dou Wu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Frequency ◽  
Buck Converter ◽  
Automotive Electronics ◽  
Loop Area ◽  
Conducted Emission ◽  
Ac Current ◽  
Radiation Noise ◽  
Cispr 25 ◽  
Output Filter

DC-DC buck converter has been more widely used in automotive electronics because of its advantage of high efficiency and small size. However, it is one of the main causes of the conducted emission and radiation noise. The working principle and the mechanism of DC-DC buck converter which generate conducted emission and radiation noise in different frequency were analyzed. Then, two methods were proposed to reduce the low frequency radiated emission. One is weakening the AC current value of the inductor current through increasing the value of the output inductor, the other is reducing the loop area by adding the output filter, and both of the methods were verified by comparative test. Finally, the two schemes were used in designing the On-board controller, and it passed the radiated emissions (ALSE method) according to the international standard CISPR 25-2008.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Detection of a point defect in a silicon single crystal by high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 466-467
Author(s):  
M. Awaji
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Point Defect ◽  
Point Defects ◽  
Noise Level ◽  
Dark Field ◽  
Silicon Single Crystal ◽  
High Resolution Image ◽  
Dark Field Imaging ◽  
Field Imaging

It is necessary to improve the resolution, brightness and signal-to-noise ratio(s/n) for the detection and identification of point defects in crystals. In order to observe point defects, multi-beam dark-field imaging is one of the useful methods. Though this method can improve resolution and brightness compared with dark-field imaging by diffuse scattering, the problem of s/n still exists. In order to improve the exposure time due to the low intensity of the dark-field image and the low resolution, we discuss in this paper the bright-field high-resolution image and the corresponding subtracted image with reference to a changing noise level, and examine the possibility for in-situ observation, identification and detection of the movement of a point defect produced in the early stage of damage process by high energy electron bombardment.The high-resolution image contrast of a silicon single crystal in the [10] orientation containing a triple divacancy cluster is calculated using the Cowley-Moodie dynamical theory and for a changing gaussian noise level. This divacancy model was deduced from experimental results obtained by electron spin resonance. The calculation condition was for the lMeV Berkeley ARM operated at 800KeV.

Sign in / Sign up

Export Citation Format

Share Document