Analysis of EMI Reduction Effect of a Magnetorheological Fluid-Gap Inductor in a DC/DC Converter

Dong-Gyu Sung,Dong-Hun Kim,Honnyong Cha,Su-Han Kim,Jin-Kyu Byun IEEE 2015 IEEE transactions on magnetics Vol.51 No.3

<P>In this paper, the electromagnetic interference reduction effect of a magnetorheological (MR) fluid-gap inductor in a dc/dc converter is investigated. For a realistic electromagnetic simulation, a prototype MR fluid-gap inductor is built and put in a typical buck converter setup, and the current waveform of the inductor is measured. Based on the measured current waveform, a 3-D time domain finite element electromagnetic analysis is performed considering non-linearity of an MR fluid and complex geometry of the winding. The rms and maximum values of the leakage flux and eddy current losses of the MR fluid-gap inductor are calculated and compared with those of the air-gap inductor. It is predicted that the eddy current heat source due to the leakage flux from the gap is reduced by as much as 75.6% for the MR fluid-gap inductor. To verify the simulation data, the leakage fluxes of both MR fluid-gap and air-gap types of inductors are measured in a dc/dc converter setup, and their experimental results are compared with calculated ones.</P>

Improving differential mode inductance in toroidal common mode inductors

Kaining Fu,Zhenzhu Lian,Wei Lan,Damin Zhang 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.12

Toroidal inductors are widely used in switch mode power supplies to attenuate electromagnetic interference (EMI). However, conventional common mode (CM) inductors have limitations in achieving diff erential mode (DM) noise attenuation and may introduce near-field coupling. In this paper, the advantage and disadvantage of conventional CM inductors are investigated. An integrated inductor scheme is proposed to overcome the limitation. The proposed scheme maintains the same CM inductance as conventional toroidal CM inductors while significantly increasing the DM inductance and reducing leakage flux. This leads to reduced weight and size of discrete DM inductors and enables higher power density of the converter. The theoretical analysis is conducted using the equivalent magnetic reluctance model. Further validation is performed through 3D finite element method simulations, insertion loss measurements, and CM and DM noise spectrum measurements. Results demonstrate that the proposed integrated inductor scheme offers superior EMI performance compared with conventional CM inductors.

Optimization of Powder Core Inductors of Buck-Boost Converters for Hybrid Electric Vehicles

You, Bong-Gi,Kim, Jong-Soo,Lee, Byoung-Kuk,Choi, Gwang-Bo,Yoo, Dong-Wook The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.4

In the present paper, the characteristics of Mega-Flux$^{(R)}$, JNEX-Core$^{(R)}$, amorphous and ferrite cores are compared to the inductor of buck-boost converters for Hybrid Electric Vehicles. Core losses are analyzed at the condition of 10 kHz sine wave excitations, and permeability fluctuations vs. temperature and magnetizing force will be analyzed and discussed. Under the specifications of the buck-boost converter for 20 kW THS-II, the power inductor will be designed with Mega-Flux$^{(R)}$ and JNEX-Core$^{(R)}$, and informative simulation results will be provided with respect to dc bias characteristics, core and copper losses.

Optimization of Powder Core Inductors of Buck-Boost Converters for Hybrid Electric Vehicles

Bong-Gi You,Jong-Soo Kim,Byoung-Kuk Lee,Gwang-Bo Choi,Dong-Wook Yoo 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.4

In the present paper, the characteristics of Mega-Flux<SUP>®</SUP>, JNEX-Core<SUP>®</SUP>, amorphous and ferrite cores are compared to the inductor of buck-boost converters for Hybrid Electric Vehicles. Core losses are analyzed at the condition of 10 ㎑ sine wave excitations, and permeability fluctuations vs. temperature and magnetizing force will be analyzed and discussed. Under the specifications of the buck-boost converter for 20 ㎾ THS-Ⅱ, the power inductor will be designed with Mega-Flux<SUP>®</SUP> and JNEX-Core<SUP>®</SUP>, and informative simulation results will be provided with respect to dc bias characteristics, core and copper losses.

A Novel Quasi-Resonant Snubber-Assisted ZCS-PWM DC-DC Converter with High Frequency Link

Khairy Fathy,Soon-Kurl Kwon 전력전자학회 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.2

In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC converter with two simple auxiliary commutation lossless inductor snubbers is presented. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC converter can regulate its DC output AC power under a principle of constant frequency edge-resonant soft switching commutation by an asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation results from an applications point of view.

Highly extendable multi‑channel LED driver with leakage energy recycling

Xianghong Kong,Junfeng Liu,Jun Zeng 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.7

This paper presents a single-stage single-switch multi-channel LED driver with high extendibility. The PFC module adopts a buck–boost circuit, which can achieve a high-power factor when it works in the discontinuous current mode (DCM). At the same time, the leakage inductor energy can be recycled by adding a capacitor at the primary side to reduce the voltage spike and ringing of the switch. The DC–DC module adopts a forward converter that plays the role of electrical isolation. Using capacitor charge balance, the converter can achieve output current balancing of all the channels. This converter can extend the number of output channels while using fewer capacitors than traditional LED drivers based on capacitor charge balance. In addition, the PFC module is integrated with the DC–DC module while sharing a common switch, which makes the control simple. This paper provides the concrete structure, working principle, and circuit characteristic analysis of the proposed topology. Finally, a 100 W prototype was built to verify its feasibility.

High step-up three-level DC-DC converter with three-winding coupled-inductor

Ding, Xinping,Zhao, Delin,Liu, Yun,Li, Kai,Hao, Yangyang The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.1

Due to the wide adoption of photovoltaic power generation, non-isolated high step-up DC-DC converters are becoming more and more popular. Among these converters, the switched/coupled-inductor-based converter is more attractive due to the fact that it has fewer power devices and a high efficiency. This paper presents a three-level high step-up DC-DC topology with a three-winding coupled-inductor. When compared with a conventional switched/coupled-inductor-based converter, a higher efficiency can be achieved, owing to low voltage stresses devices, fewer semiconductors in the power loop, lower current stresses, and ZCS of the main switches. The operating principle of the proposed topology is analyzed in detail via equivalent circuits, where a theoretical analysis is carried out using state space modelling. Experimental results obtained on a 24-300 V, 360 W lab prototype have verified the excellent performance of the proposed DC-DC converter.

Sub-6 GHz Noise-cancelling Balun-LNTA with Dualband Q-enhanced LC Notch Filter for 5G New Radio Cellular Applications

Donggu Lee,Kuduck Kwon 대한전자공학회 2022 Journal of semiconductor technology and science Vol.22 No.3

This paper presents a blocker-tolerant broadband balun-low-noise transconductance amplifier (LNTA) with a high-Q dual-band LC notch filter for 5G new radio (NR) sub-6GHz cellular applications. The proposed balun-LNTA employs a noise-cancelling 1:5 CG-CS balun-LNA topology with local feedback gm-boosting and modified currentbleeding techniques to support entire bands of sub-6 GHz 5G NR application with less than 5 dB NF performance and balanced output of balun-LNTA. The dual-band Q-boosted LC notch filter with a bandswitchable differential inductor is also proposed to enhance blocker tolerance of the receiver by removing out-of-band blockers and strong transmitter leakage signals. Simulated in a 65-nm CMOS process, the designed balun-LNTA achieves a minimum noise figure of 2.38 dB, a maximum transconductance gain of 44 mS, an S11 of less than ‒10 dB over the frequency range of 50 MHz-6 GHz, an input-referred third-order intercept point of 1.82 dBm, and blocker rejection ratios of more than 15 dB. It consumes 5.9 mA from a nominal supply voltage of 1 V. Its active die area is 0.55 mm2.

A Novel Quasi-Resonant Snubber Assisted ZCS-PWM Soft-Switching DC-DC Converter

Khairy Fathy,Hyun Woo Lee,Mutsuo Nakaoka 전력전자학회 2006 전력전자학술대회 논문집 Vol.- No.-

In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC Converter with two simple auxiliary commutation lossless inductor snubbers. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC Converter can regulate its dc output AC power under a principle of constant frequency edge-resonant soft switching commutation by asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC Converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation a results from an application point of view.

A Novel Quasi-Resonant Snubber-Assisted ZCS-PWM DC-DC Converter with High Frequency Link

Fathy, Khairy,Kwon, Soon-Kurl The Korean Institute of Power Electronics 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.2

In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC converter with two simple auxiliary commutation lossless inductor snubbers is presented. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC converter can regulate its DC output AC power under a principle of constant frequency edge-resonant soft switching commutation by an asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation results from an applications point of view.