scholarly journals Analysis of Unidirectional Secondary Resonant Single Active Bridge DC–DC Converter

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6349
Author(s):  
Cao Anh Tuan ◽  
Takaharu Takeshita
Keyword(s):  
High Frequency ◽  
Design Method ◽  
Total Power ◽  
Resonant Circuit ◽  
Frequency Variation ◽  
Secondary Circuit ◽  
High Frequency Transformer ◽  
Resonant Capacitor ◽  
Voltage Conversion ◽  
Near Future

A compact and highly efficient unidirectional DC–DC converter is required as a battery charger for electrical vehicles, which will rapidly become widespread in the near future. The single active bridge (SAB) converter is proposed as a simple and high-frequency isolated unidirectional converter, which is comprised of an active H-bridge converter in the primary side, an isolated high frequency transformer, and a rectifying secondary diode bridge output circuit. This paper presents a novel, unidirectional, high-frequency isolated DC–DC converter called a Secondary Resonant Single Active Bridge (SR–SAB) DC–DC converter. The circuit topology of the SR–SAB converter is a resonant capacitor connected to each diode in parallel in order to construct the series resonant circuit in the secondary circuit. As a result, the SR–SAB converter achieves a higher total power factor at the high frequency transformer and a unity voltage conversion ratio under the unity transformer turns ratio. Small and nonsignificant overshoot values of current and voltage waveforms are observed. Soft-switching commutations of the primary H-bridge circuit and the soft recovery of secondary diode bridge are achieved. The operating philosophy and design method of the proposed converter are presented. Output power control using transformer frequency variation is proposed. The effectiveness of the SR–SAB converter was verified by experiments using a 1 kW, 48 VDC, and 20 kHz laboratory prototype.

A Design Method of High Frequency Transformer for DC-DC Converter

2018 ◽  
Vol 44 (0) ◽  
pp. 90-96
Author(s):  
Toru Miyoshi ◽  
Akira Kawata ◽  
Shigeo Masukawa
Keyword(s):  
High Frequency ◽  
Design Method ◽  
High Frequency Transformer

Behaviour of a high-intensity discharge lamp fed by a high-frequency dimmable electronic ballast

2016 ◽  
Vol 49 (2) ◽  
pp. 277-284 ◽  
Author(s):  
A Chammam ◽  
W Nsibi ◽  
M Nejib Nehdi ◽  
B Mrabet ◽  
A Sellami
Keyword(s):  
Power Factor ◽  
High Intensity ◽  
High Frequency ◽  
Power Factor Correction ◽  
Acoustic Resonance ◽  
Operating Frequency ◽  
Resonant Circuit ◽  
Frequency Variation ◽  
Luminous Efficacy ◽  
Wide Range

The main advantages of high-frequency electronic ballasts for high-intensity discharge lamps are high luminous efficacy, small size, lightweight and longer lifetime. This is why high-intensity discharge lamps operating at high frequency are widely used. This paper proposes an approach for designing resonant circuit electronic ballasts controlled by frequency variation for high-intensity discharge lamps. The proposed technique including an AC/DC rectifier, a power factor correction circuit and a DC/AC half bridge inverter. These electronic ballasts offer a wide range of dimming controls and can avoid acoustic resonance. However, under dimming, the electric and photometric characteristics of the lamp change. In order to study these effects under the process of dimming, this work studies the lamp properties by varying both lamp power and operating frequency.

Modeling of the AC/HF/DC converter with power factor correction

2010 ◽  
Vol 59 (3-4) ◽  
pp. 141-152
Author(s):  
Antoni Bogdan
Keyword(s):  
Power Factor ◽  
High Frequency ◽  
Power Factor Correction ◽  
Modulation Method ◽  
Resonant Circuit ◽  
Modeling Approach ◽  
High Frequency Transformer ◽  
Pulse Density ◽  
Density Modulation ◽  
Correction System

Modeling of theAC/HF/DCconverter with power factor correctionIn this paper, the power factor correction system consisted of: bridge converter, parallel resonant circuit, high frequency transformer, diode rectifier andLFCFfilter is presented. This system is controlled by a pulse density modulation method and the principle of its operation is based on the boost technique. The modeling approach is illustrated by an example usingAC/HF/DCconverter. Verification of the derived model is provided, which demonstrated the validity of the proposed approach.

Comparison of wavelet continuous transform and signal averaged ECG for high frequency content and late potential detection in healthy individuals

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Garcia Iglesias ◽  
J.M Rubin Lopez ◽  
D Perez Diez ◽  
C Moris De La Tassa ◽  
F.J De Cos Juez ◽  
...  
Keyword(s):  
High Frequency ◽  
Classical Method ◽  
Total Power ◽  
Frequency Content ◽  
Healthy Individuals ◽  
Time Frequency ◽  
Qt Intervals ◽  
Long Time ◽  
Power Content ◽  
High Frequency Content

Abstract Introduction The Signal Averaged ECG (SAECG) is a classical method forSudden Cardiac Death (SCD) risk assessment, by means of Late Potentials (LP) in the filtered QRS (fQRS)[1]. But it is highly dependent on noise and require long time records, which make it tedious to use. Wavelet Continuous Transform (WCT) meanwhile is easier to use, and may let us to measure the High Frequency Content (HFC) of the QRS and QT intervals, which also correlates with the risk of SCD [2,3]. Whether the HFC of the QRS and QT measured with the WCT is a possible subrogate of LP, has never been demonstrated. Objective To demonstrate if there is any relationship between the HFC measured with the WCT and the LP analyzed with the SAECG. Methods Data from 50 consecutive healthy individuals. The standard ECG was digitally collected for 3 consecutive minutes. For the WCT Analysis 8 consecutive QT complexes were used and for the SAECG Analysis all available QRS were used. The time-frequency data of each QT complex were collected using the WCT as previously described [3] and the Total, QRS and QT power were obtained from each patient. For the SAECG, bipolar X, Y and Z leads were used with a bidirectional filter at 40 to 250 Hz [1]. LP were defined as less than 0.05 z in the terminal part of the filtered QRS and the duration (SAECG LP duration) and root mean square (SAECG LP Content) of this LP were calculated. Pearson's test was used to correlate the Power content with WCT analysis and the LP in the SAECG. Results There is a strong correlation between Total Power and the SAECG LP content (r=0.621, p<0.001). Both ST Power (r=0.567, p<0.001) and QRS Power (r=0.404, p=0.004) are related with the SAECG LP content. No correlation were found between the Power content (Total, QRS or ST Power) and the SAECG LP duration. Also no correlation was found between de SAECG LP content and duration. Conclusions Total, QRS and ST Power measured with the WCT are good surrogates of SAECG LP content. No correlation were found between WCT analysis and the SAECG LP duration. Also no correlation was found between the SAECG LP content and duration. This can be of high interest, since WCT is an easier technique, not needing long recordings and being less affected by noise. Funding Acknowledgement Type of funding source: None

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