scholarly journals Conducted Emi Model for Flyback PFC Converter

2019 ◽  
Vol 8 (3) ◽  
pp. 6916-6923
Keyword(s):  
Power Factor ◽  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Input Power ◽  
International Standards ◽  
Noise Sources ◽  
Flyback Converter ◽  
Full Compliance ◽  
Switched Mode Power Supply ◽  
Conducted Emi

Power Factor Correction (PFC) units are used at the front end of Switched Mode Power Supply (SMPS) to improve the input power factor. However, they generate Electromagnetic Interference (EMI) which needs to be mitigated to compliant levels prescribed by International Standards. The Electromagnetic Compatibility (EMC) standards have set regulations which require expensive instruments and environment for their measurement. Hence there is a need for predicting Conducted EMI by simulation before the product is tested for full compliance to reduce the complexity of the circuit design and cost. To estimate the Conducted EMI, it is important to identify the main noise sources and their conduction paths. This can be achieved by simulating the circuit using the exact models of the transformer, capacitor, PCB trace, and the switching semiconductors. In this paper these components of PFC flyback converter are modelled using SPICE models, datasheet defined component parameters and experimental measurements. The theoretical analysis and simulation results show that the method discussed can predict and analyse the Conducted EMI. This is tested experimentally on a Flyback PFC converter working in Critical Conduction Mode. A line filter is designed and used to bring the noise to compliant levels. Simulation and Experimental results after using the line filter are also presented.

Antenna Calibration Methods for Antenna Factor Measurements

2012 ◽  
Vol 2 (4) ◽  
pp. 43-59 ◽  
Author(s):  
L. Mescia ◽  
O. Losito ◽  
V. Castrovilla ◽  
P. Bia ◽  
F. Prudenzano
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Ground Plane ◽  
Empty Space ◽  
Horn Antenna ◽  
International Standards ◽  
Impedance Method ◽  
Calibration Methods ◽  
Antenna Impedance ◽  
Antenna Factor

In the fields of electromagnetic interference and electromagnetic compatibility, it is important to measure the strength of the electric field originating from electric devices. For this purpose, knowledge of the antenna factor of a receiving antenna is necessary. According to international standards, the accurate measurement of the antenna factor involves the use of calibration test sites characterized by very large sizes of both the ground plane and the empty space volume above it. As a consequence, these setup conditions make the antenna factor measurements quite expensive for the customer. In this paper, the authors discuss the well know antenna-based and site-based methods as well as recently measurement method called Antenna Impedance Method as able to obtain the free-space antenna factor. Moreover, the authors investigate on the suitability of semi-anechoic chamber for reliable antenna factor calibrations. In particular, the experimental measurements of the antenna factor obtained by using the antenna impedance method were compared with Standard Field Method and the data provided by the manufacturer of three antennas (Biconical, Log-periodic and Horn antenna) founding an agreement with the international standard ANSI C63.5-2006.

scholarly journals Design a Single Stage AC to DC Converter for LED Driver With Power Factor Improvement

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3312-3318
Keyword(s):  
Power Factor ◽  
Low Voltage ◽  
Input Power ◽  
Boost Converter ◽  
Led Driver ◽  
Peak Voltage ◽  
Flyback Converter ◽  
Snubber Circuit ◽  
Driver Circuit ◽  
Dc Bus

This paper shows the design of a single switch LED driver circuit which is based on the operation of boost converter and flyback converter with power factor correction. In the proposed driver circuit, the boost converter is made to operate in DCM mode for achieving a high power factor and the flyback converter is used for isolating the input-output in order to provide safety. In addition to this, a snubber circuit is also designed for clamping the peak voltage of the main switch into low voltage and also to recycle the leakage inductor energy. A capacitor of low-voltage rating is made to function as the DC bus capacitor due to reason that some amount of the input power is conducted directly towards the output side; the amount of power remaining is then stored in the DC bus capacitor. In this way, the proposed LED driver circuit provides a power factor of greater value, i.e., above 0.95 PF and also a high value of power conversion efficiency, i.e., above 90%.

Effects of Switching Frequency Modulation on Input Power Quality of Boost Power Factor Correction Converter

2017 ◽  
Vol 8 (2) ◽  
pp. 882 ◽  
Author(s):  
Deniss Stepins ◽  
Jin Huang
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Frequency Modulation ◽  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Power Factor Correction ◽  
Harmonic Distortion ◽  
Input Power ◽  
Switching Frequency

Switching frequency modulation (SFM) as spread-spectrum technique has been used for electromagnetic interference reduction in switching power converters. In this paper, a switching-frequency-modulated boost power factor correction (PFC) converter operating in continuous conduction mode is analysed in detail in terms of its input power quality. Initially, the effect of SFM on the input current total harmonic distortion, power factor and low-frequency harmonics of the PFC converter are studied by using computer simulations. Some advices on choosing parameters of SFM are given. Then the theoretical results are verified experimentally. It is shown that, from a power quality point of view, SFM can be harmful (it can significantly worsen the power quality of the PFC converter) or almost harmless. The results depend on how properly the modulation parameters are selected.

scholarly journals Design and Implementation of 150 W AC/DC LED Driver with Unity Power Factor, Low THD, and Dimming Capability

Electronics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Ngo Thanh Tung ◽  
Nguyen Dinh Tuyen ◽  
Nguyen Minh Huy ◽  
Nguyen Hoai Phong ◽  
Ngo Cao Cuong ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Power Factor ◽  
Electromagnetic Interference ◽  
Light Emitting Diode ◽  
Power Converter ◽  
Input Power ◽  
Led Driver ◽  
Load Range ◽  
Dc Power ◽  
Wide Range

This paper presents the implementation of a two-stage light-emitting diode (LED) driver based on commercial integrated circuits (IC). The presented LED driver circuit topology, which is designed to drive a 150 W LED module, consists of two stages: AC-DC power factor correction (PFC) stage and DC/DC power converter stage. The implementation of the PFC stage uses IC NCP1608, which uses the critical conduction mode to guarantee a unity input power factor with a wide range of input voltages. The DC/DC power converter with soft-switching characteristics for the entire load range uses IC FLS2100XS. Furthermore, the design of an electromagnetic interference (EMI) filter for the LED driver and the dimming control circuit are discussed in detail. The hardware prototype, an LED lighting system, with a rated power of 150 W/32 V from a nominal 220 V/50 Hz AC voltage supply was tested to show the effectiveness of the design. The presented LED driver was tested for street lighting, and the experimental results show that the power factor (PF) was higher than 0.97, the total harmonics distortion (THD) was lower than 7%, and the efficiency was 91.7% at full load. The results prove that the performance of the presented LED driver complies with the standards: IEC61000-3-2 and CIRSP 15:2009.

scholarly journals Input/Output EMI Filter Design for Three-Phase Ultra-High Speed Motor Drive GaN Inverter Stage

2021 ◽  
Vol 6 (1) ◽  
pp. 74-92
Author(s):  
Michael Antivachis ◽  
Keyword(s):  
Electromagnetic Interference ◽  
High Speed ◽  
Electromagnetic Compatibility ◽  
Filter Design ◽  
Mutual Influence ◽  
Motor Drives ◽  
Motor Drive ◽  
Input Side ◽  
Output Side ◽  
Conducted Emi

Pairing wide-bandgap (WBG) inverters with high-speed motors results in compact and effi cient motor drives, but requires special attention on electromagnetic interference (EMI) aspects. This paper focuses on electromagnetic compatibility (EMC) of high-speed motor drives, supplied by a DC source. In order to protect the nearby equipment from the EMI noise of the WBG inverter, a fi lter that complies with conducted EMI regulations is placed at the inverter DC input-side. However, there is no clear mandate requiring from inverters to comply with conducted EMI regulations at the AC output-side, where only the motor is placed. For this reason, there is no full consensus whether it is necessary to use an output fi lter, and if so, what type of output fi lter would be suitable, i.e., if differential-mode (DM), common-mode (CM) or both DM/CM output fi lter would fi t best. A full sine-wave output fi lter (FSF) is proposed in this paper, that features both DM and CM attenuation, and capacitors connected to the DC link. Besides the several well established benefi ts of a FSF, such as purely sinusoidal motor currents and the protection of the motor against high du/dt originating from the fast switching of the semiconductor devices, a FSF at the inverter output-side, also reduces the CM EMI emissions at the inverter input-side. Namely, since the inverter housing, the motor housing and the interconnecting shielded cable are all grounded, CM emissions generated at the inverter output-side are directly mapped to the inverter input-side, i.e., there is an input-to-output CM noise interrelation. A FSF reduces the output-side CM EMI emissions and thus mitigates the input-to-output CM noise mutual influence. Two types of FSF (c-FSF and d-FSF) are comparatively evaluated, in terms of volume, losses and EMI performance. The theoretical consideration are tested within the context of a high-speed 280 krpm, 1 kW motor drive, with 80 V DC supply. The experimental results validate the good performance of the proposed filter concept.

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