scholarly journals Active Clamp Boost Converter with Blanking Time Tuning Considered

2021 ◽  
Vol 11 (2) ◽  
pp. 860
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Yu-Kun Tai

An active clamp boost converter with blanking time auto-tuned is presented herein, and this is implemented by an additional auxiliary switch, an additional resonant inductor, and an additional active clamp capacitor as compared with the conventional boost converter. In this structure, both the main and auxiliary switches have zero voltage switching (ZVS) turn-on as well as the output diode has zero current switching (ZCS) turn-off, causing the overall efficiency of the converter to be upgraded. Moreover, as the active clamp circuit is adopted, the voltage spike on the main switch can be suppressed to some extent whereas, because of this structure, although the input inductor is designed in the continuous conduction mode (CCM), the output diode can operate with ZCS turn-off, leading to the resonant inductor operating in the discontinuous conduction mode (DCM), hence there is no reverse recovery current during the turn-off period of the output diode. Furthermore, unlike the existing soft switching circuits, the auto-tuning technique based on a given look-up table is added to adjust the cut-off time point of the auxiliary switch to reduce the current flowing through the output diode, so that the overall efficiency is upgraded further. In this paper, basic operating principles, mathematic deductions, potential designs, and some experimental results are given. To sum up, the novelty of this paper is ZCS turn-off of the output diode, DCM operation of the resonant inductor, and auto-tuning of cut-off time point of the auxiliary switch. In addition, the efficiency of the proposed converter can be up to 96.9%.

Author(s):  
Riz Rifai O. Sasue ◽  
Eka Firmansyah ◽  
Suharyanto Suharyanto

Interleaved boost converter gives good conversion efficiency due to its zero-current switching capability when operating in discontinuous conduction mode while keeping its input-output ripple current low. However, operating this kind of converter at interleaved operation for all the time gives poor efficiency under light-load condition. In this paper, an automatic operation region selector switch based on detection of the continuous or discontinuous current mode is proposed. With this switch, during the light-load condition, only one converter is activated, while during full-load condition both converters will be activated. The simulation results using LTspice software show that the proposed boost converter has a better efficiency compared to the conventional boost converter with efficiency range of 84.6 % to 95.32 % under various load conditions.


The conversion of A.C to D.C determines the distortion of the mains current A.C., which degrades the input power factor. The main reason for a poor power factor is the non-linear nature of the circuit. In this paper power factor is improved by using a basic boost converter and a control technique based on the fixed off time(FOT) approach .The traditional approach to the correction of the power factor in the boost converter is the continuous conduction mode with fixed frequency (FF-CCM) and the transition mode (TM) PWM (fixed connection time, variable frequency). In the first mode, the inductor operates in continuous conduction mode (CCM) and uses the average current-mode control mode; a complex technique involves a considerable number of components. The second method uses the more complex control technique of the peak current mode that makes the inductor work between continuous and discontinuous mode, which uses fewer components, unstable greater than 50% duty cycle and is more cost efficient. A third approach, the fixed off time (FOT) is gaining popularity which is conditionally stable for a duty cycle of over 50% and does not need compensation. The paper work carried out to use the power factor correction (PFC) based on DC-DC Flyback converter. To verify the design and operation of the circuit, the simulation is performed in PSIM .A prototype is developed and results are presented.


2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Cao Taiqiang ◽  
Chen Zhangyong ◽  
Wang Jun ◽  
Sun Zhang ◽  
Luo Qian ◽  
...  

In order to implement a high-efficiency bridgeless power factor correction converter, a new topology and operation principles of continuous conduction mode (CCM) and DC steady-state character of the converter are analyzed, which show that the converter not only has bipolar-gain characteristic but also has the same characteristic as the traditional Boost converter, while the voltage transfer ratio is not related with the resonant branch parameters and switching frequency. Based on the above topology, a novel bridgeless Bipolar-Gain Pseudo-Boost PFC converter is proposed. With this converter, the diode rectifier bridge of traditional AC-DC converter is eliminated, and zero-current switching of fast recovery diode is achieved. Thus, the efficiency is improved. Next, we also propose the one-cycle control policy of this converter. Finally, experiments are provided to verify the accuracy and feasibility of the proposed converter.


Author(s):  
G. NARESH GOUD ◽  
Y. LAKSHMI DEEPA ◽  
G.DILLI BABU ◽  
P. RAJASEKHAR ◽  
N. GANGADHER

A new soft-switching boost converter is proposed in this paper. The conventional boost converter generates switching losses at turn ON and OFF, and this causes a reduction in the whole system’s efficiency. The proposed boost converter utilizes a soft switching method using an auxiliary circuit with a resonant inductor and capacitor, auxiliary switch, and diodes. Therefore, the proposed soft-switching boost converter reduces switching losses more than the conventional hard-switching converter. The efficiency, which is about 91% in hard switching, increases to about 97% in the proposed soft-switching converter. In this paper, the performance of the proposed soft-switching boost converter is verified through the theoretical analysis, simulation, and experimental results.


2014 ◽  
Vol 778-780 ◽  
pp. 1030-1033 ◽  
Author(s):  
Sei Hyung Ryu ◽  
Craig Capell ◽  
Charlotte Jonas ◽  
Michael J. O'Loughlin ◽  
Jack Clayton ◽  
...  

A 1 cm x 1 cm 4H-SiC N-IGBT exhibited a blocking voltage of 20.7 kV with a leakage current of 140 μA, which represents the highest blocking voltage reported from a semiconductor power switching device to this date. The device used a 160 μm thick drift layer and a 1 μm thick Field-Stop buffer layer, and showed a VF of 6.4 V at an IC of 20 A, and a differential Ron,sp of 28 mΩ-cm2. Switching measurements with a supply voltage of 8 kV were performed, and a turn-off time of 1.1 μs and turn-off losses of 10.9 mJ were measured at 25°C, for a 8.4 mm x 8.4 mm device with 140 μm drift layer and 2 μm F-S buffer layer. The turn-off losses were reduced by approximately 50% by using a 5 μm F-S buffer layer. A 55 kW, 1.7 kV to 7 kV boost converter operating at 5 kHz was demonstrated using the 4H-SiC N-IGBT, and an efficiency value of 97.8% was reported.


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