Research on Conducted EMI in Power Converter

2012 ◽  
Vol 516-517 ◽  
pp. 1808-1811
Author(s):  
Bin Liang

This paper researches differential mode (DM) conducted electromagnetic interference (EMI) in rectifier. The DM interference source generated by power electronic switches is given. Based on experimental and theoretical analysis, the conducted EMI of a three-phase rectifier is studied systematically. The study shows that it changes with resistance loads in low frequency ranges, while in high frequency bandwidth, the effect of change of the resistance load on the DM EMI is not obvious. The validity of the models is confirmed by the measurements.

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 413 ◽  
Author(s):  
Haoqi Zhu ◽  
Dongliang Liu ◽  
Xu Zhang ◽  
Feng Qu

The switching device in a power converter can produce very serious electromagnetic interference (EMI). In order to solve this problem and the associated reliability and stability issues, this article aimed to analyze and model the boost power factor correction (PFC) converter according to the EMI conduction path. The sources of common-mode (CM) and differential-mode (DM) noise of the boost PFC converter were analyzed, and the DM and CM equivalent circuits were deduced. Furthermore, high-frequency modeling of the common-mode inductor was developed using a precise model, and the EMI filter was designed. According to the Class B standard for EMI testing, it is better to restrain the EMI noise in the frequency range (150 kHz to 30 MHz) of the EMI conducted disturbance test. Using this method, a 2.4-kW PFC motor driving supply was designed, and the experimental results validate the analysis.


Author(s):  
C. Vidhya ◽  
V. Ravikumar ◽  
S. Muralidha

: The objective of this paper is to implement an ac link universal power converter controlled BLDC motor for medical applications. The ac link universal power converter is a soft switched high frequency ac link converter, created using the parallel combination of an inductor and a capacitor. The parallel ac link converter handle the ac voltages and currents with low reactive ratings at the link and offers improved power factor, low power consumption, more efficiency and less weight on comparison with the traditional dc link converter. Because of the high throughput, BLDC motors are preferred widely medical applications. A modulation technique called Space Vector Pulse Width Modulation (SVPWM) is used to generate the three phase power for the BLDC motors from the input DC supply. To validate the proposed system, simulations are performed in MATLAB – Simulink and an experimental prototype is constructed to supplement the simulation results.


2015 ◽  
Vol 655 ◽  
pp. 182-185
Author(s):  
Ke Lan Yan ◽  
Run Hua Fan ◽  
Min Chen ◽  
Kai Sun ◽  
Xu Ai Wang ◽  
...  

The phase structure, and electrical and magnetic properties of La0.7Sr0.3MnO3(LSMO)-xAg (xis the mole ratio,x=0, 0.3, 0.5) composite were investigated. It is found that the sample withx=0 is single phase; the samples withx=0.3 and 0.5 present three phase composite structure of the manganese oxide and Ag. With the increasing of Ag content, the grain size of the samples increases and the grain boundaries transition from fully faceted to partially faceted. The permittivity of spectrum (10 MHz - 1 GHz) and the theoretical simulation reveal that the plasma frequencyfpincrease with Ag content, due to the increasing of free electron concentration, which is further supported by the enhancement of conductivity. While for the permeability (μr'), theμr'decrease with the increasing of Ag content at low frequency range (f< 20 MHz), while at the relative high frequency range (f> 300 MHz), theμr'increased with Ag content. Therefore, the introduction of elemental Ag resulted in a higherμr'at the relative high frequency range.


2021 ◽  
pp. 2150050
Author(s):  
Mutaz Y. Melhem ◽  
Christiana Chamon ◽  
Shahriar Ferdous ◽  
Laszlo B. Kish

Recently, several passive and active attack methods have been proposed against the Kirchhoff–Law–Johnson–Noise (KLJN) secure key exchange scheme by utilizing direct (DC) loop currents. The DC current attacks are relatively easy, but their practical importance is low. On the other hand, parasitic alternating (AC) currents are virtually omnipresent in wire-based systems. Such situations exist due to AC ground loops and electromagnetic interference (EMI). However, utilizing AC currents for attacks is a harder problem. Here, we introduce and demonstrate AC current attacks in various frequency ranges. The attacks exploit a parasitic/periodic AC voltage-source at either Alice’s or Bob’s end. In the low-frequency case, the procedure is the generalized form of the former DC ground-loop-based attack. In the high-frequency case, the power density spectrum of the wire voltage is utilized. The attack is demonstrated in both the low and the high-frequency situations. Defense protocols against the attack are also discussed.


2011 ◽  
Vol 130-134 ◽  
pp. 3289-3292
Author(s):  
Ke Xin Wei ◽  
Rui Xia Duan ◽  
Bin Liang

Taking three phase PWM rectifier as the research object, according to interference mechanism of the rectifier bridge, this paper describes the equivalent circuit of AC side differential mode interference and calculates the interference source voltage and differential mode interference voltage of the three phase PWM rectifier AC side in 150KHz-30MHz frequency band. Then we analyze the model of the equivalent circuit diagram using the Saber software and verify the validity of the model and the accuracy of the calculation through experiments.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jianming Zhou

A design of dual broadband antenna is proposed in this paper; it consists of one low frequency unit and two high frequency units. The low frequency unit consists of a pair of printing vibrators; the high frequency unit consists of a pair of printing oscillators, which is bent at its end, and high frequency unit and low frequency unit are set on the same dielectric substrate. Through adding a parasitic unit on antenna, it can enhance frequency bandwidth without affecting the bandwidth. In the high frequency unit, it adopts gap-coupled microstrip line feeding method in order to get enough bandwidth. Through the test of dual broadband antenna, it can be found that, in the low frequency part, the antenna covers 20% bandwidth of the total bandwidth, and it covers the frequency from 800 MHz to 980 MHz. In the high frequency, the antenna covers 60% of total bandwidth and its frequency is from 1540 MHz to 2860 MHz, so the designed antenna can satisfy the frequency requirements of 2G/3G/LTE (4G) communication system.


2013 ◽  
Vol 284-287 ◽  
pp. 2516-2520 ◽  
Author(s):  
Pavel Drabek ◽  
Vaclav Kus

Power electronic converters produce not only characteristic harmonics, but also both non-characteristic harmonics and interharmonics. This paper presents the physical background of both non-characteristic harmonics and interharmonics. Generation causes are explored and discussed in detail. Extensive series of simulation of different power converter topologies are provided and compared with experimental results and existing standards. This research offers missing background for standards covering low-frequency EMC.


Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3698 ◽  
Author(s):  
Hermes Loschi ◽  
Robert Smolenski ◽  
Piotr Lezynski ◽  
Douglas Nascimento ◽  
Galina Demidova

The assessment of electromagnetic compatibility (EMC) is important for both technical and legal reasons. This manuscript addresses specific issues that should be taken into account for proper EMC assessment of energy systems that use power electronic interfaces. The standardized EMC measuring techniques have been used in a laboratory setup consisting in two identical DC/DC converters with deterministic and random modulations. Measuring difficulties caused by the low frequency envelopes, resulting from frequency beating accompanying aggregation of harmonic components of similar frequencies, were indicated as a phenomenon that might lead to significant problems during the EMC assessment using currently binding standards. The experimental results describing deterministic and random modulated converters might be useful for practitioners implementing power interfaces in microgrids and power systems as well as for researchers involved in EMC assurance of power systems consisting in multiple power electronic interfaces.


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