Conventional Interleaved Buck Converter Research Articles

Asymmetric ZVS Buck Converters With High-Step-Down Conversion Ratio

This article proposes a family of asymmetric high-step-down converters in which zero voltage switching (ZVS) is achieved and common ground between the input and the output is retained. The proposed converters are derived from the multiphase coupled-buck converter and both coupled inductors and series capacitors are employed in order to achieve a high-step-down conversion ratio. Therefore, the voltage stress across the freewheeling diodes and the current stress of the main switches are reduced. Furthermore, switching losses including turn-on, turn-off, capacitive turn-on, and reverse recovery losses are considerably reduced due to the soft switching of semiconductor devices. As a result, the converter can efficiently operate at higher switching frequencies. Also, in comparison to the conventional interleaved buck converter (IBC) the cost, volume, weight, and complexity of the proposed topologies have not increased significantly as the proposed converters use the minimum number of auxiliary components and, similar to the conventional IBC, share the common ground. The validity of this research is confirmed by the experimental results of a 150 V to 12 V/15 A prototype.

Two‐phase high efficiency interleaved buck converter with improved step‐down conversion ratio and low voltage stress

A two-phase interleaved buck converter (IBC) providing a high step-down conversion ratio is proposed in this study. The proposed IBC uses a switch-capacitor cell to achieve a high step-down conversion ratio compared to the conventional IBC. The cell consists of two parallel switches and two crossly placed identical capacitors. These identical capacitors are charged in series and discharged in parallel by producing a lower output voltage compared to the conventional IBC at the same duty ratio. The proposed converter provides less voltage and current stresses. The operation principle, the ripple and the average current through the inductors are described in continuous conduction mode. The boundary load condition is also determined. By describing the charging and discharging of the two identical capacitors of the cell, the capacitance value is determined. The losses and efficiency are analysed, and 96.33% efficiency is achieved. Finally, the proposed converter is implemented and experimental results are provided.

Interleaved Buck Converter With Continuous Input Current, Extremely Low Output Current Ripple, Low Switching Losses, and Improved Step-Down Conversion Ratio

This paper proposes an interleaved buck converter (IBC) with continuous input current, extremely low output current ripple, low switching losses, and improved step-down conversion ratio. Unlike the conventional IBC, the proposed converter has a continuous input current, and its output current ripple is extremely low. The proposed converter has a lower voltage stress in comparison to the conventional IBC and can also provide a high step-down ratio, which makes it a proper choice for high-power applications where a nonisolated step-down converter with low output current ripple and continuous input current is required. Also, the proposed converter can provide current sharing between two interleaved modules without using additional current-sharing control method. All of these benefits are obtained without any additional stress on the circuit components. A prototype converter with 200-V input and 24-V–10-A output is implemented to verify the theoretical analysis. Operational principles and experimental results are presented in this paper.

소프트 스위칭 방식을 적용한 고효율 인터리브드 벅 컨버터

In this paper, a soft-switching scheme for the PWM interleaved buck converter(IBC) is newly proposed to obtain the advantages of both the conventional PWM interleaved buck and resonant converters such as ease of control, reduced switching losses and stresses, and low EMI. To obtain the soft-switching action, the proposed scheme employs an auxiliary circuit, which is added to the conventional interleaved buck converter and used to achieve soft-switching for both the main switches and the output diodes while not incurring any additional losses due to the auxiliary circuit itself. In this paper, the basic operations are discussed and design guidelines are presented. And through the experimental results, the usefulness of the proposed converter is verified.

소프트 스위칭 형태의 보조 회로를 이용한 인터리브드 벅 컨버터

This paper proposes the interleaved buck converter using a soft switching auxiliary circuit. In this scheme, an auxiliary circuit is added to the conventional interleaved buck converter and used to achieve soft-switching conditions for both the main switch and freewheeling diode. In addition, the switch in the auxiliary circuit operates under soft-switching conditions. Also, according to the input to output conditions, the main switch achieved zero-current-transition(ZCT) or zero-current & zero-voltage-transition(ZCZVT) at turn on. Thus, the proposed interleaved buck converter provides a higher efficiency. The basic operations, in this paper, are discussed and design guidelines are presented. The usefulness of the proposed converter is verified on a 200kHz, 180W prototype converter.

Design and MATLAB Simulation of a Fuel Cell Based Interleaved Buck Converter with Low Switching Losses and Improved Conversion Ratio

The Interleaved Buck Converter (IBC) having low switching losses and improved step-down conversion ratio is suitable for the applications where the input voltage is high and the operating duty is below 50%. It is similar to the conventional IBC, but two active switches are connected in series and a coupling capacitor is employed in the power path. This IBC shows that since the voltage stress across all the active switches is half of the input voltage before turn-on or after turn-off when the operating duty is below 50%, the capacitive discharging and switching losses can be reduced considerably. This allows the IBC to have higher efficiency and operate with higher switching frequency. In addition, it has a higher step-down conversion ratio and a smaller output current ripple compared with a conventional IBC. Closed loop control using PI controller has been done to improve the system performances. By replacing the conventional voltage source by a renewable one will enhance its reliability and is more economical. So here the dynamics of a polymer electrolyte membrane fuel cell (PEM Fuel cell) is modelled, simulated and presented. MATLAB -SIMULINK is used for the modelling and simulation of the fuel cell stack. Design and analysis of the converter is done for a DC input of 200V and duty ratio D<0.5. The expected output DC voltage is 24V/10A. Simulation of both conventional and new IBC is done using MATLAB/SIMULINK and their outputs are compared.

Interleaved Buck Converter Having Low Switching Losses and Improved Step-Down Conversion Ratio

This paper proposes a new interleaved buck converter (IBC) having low switching losses and improved step-down conversion ratio, which is suitable for the applications where the input voltage is high and the operating duty is below 50%. It is similar to the conventional IBC, but two active switches are connected in series and a coupling capacitor is employed in the power path, such as Cuk, Sepic, and Zeta converters. The proposed IBC shows that since the voltage stress across all the active switches is half of the input voltage before turn-on or after turn-off when the operating duty is below 50%, the capacitive discharging and switching losses can be reduced considerably. This allows the proposed IBC to have higher efficiency and operate with higher switching frequency. In addition, the proposed IBC has a higher step-down conversion ratio and a smaller output current ripple compared with a conventional IBC. The features, operation principles, and relevant analysis results of the proposed IBC are presented in this paper. The validity of this study is confirmed by the experimental results of prototype converters with 150-200 V input, 24 V/10 A output.