Traditional high step-up DC–DC converters for renewable energy sources (RESs) often suffer from critical limitations, including the requirement for extreme duty cycles to achieve high voltage gains, elevated voltage and current stresses on semiconductors, and the imposition of full output voltage on the output capacitor and diodes. This paper presents a single-switch, non-isolated high step-up DC–DC converter that overcomes these challenges by combining a coupled inductor (CI) and voltage multiplier (VM) cells with a modified buck–boost–converter-based structure. The proposed topology achieves a high voltage conversion ratio while effectively distributing voltage stresses among the circuit components. The coupled inductor mitigates diode reverse-recovery problems, and a passive clamp circuit suppresses voltage spikes arising from leakage inductance, thereby reducing switch stress and enhancing its efficiency. Comprehensive theoretical analysis, along with comparative evaluations against similar configurations, demonstrates that the proposed converter delivers high voltage gain across the full duty-cycle range with the minimum normalized switch voltage stress. It also exhibits among the lowest diode voltage stresses and utilizes relatively low-value passive components, all within a simple structure employing only one power switch and one magnetic core. Four extended topologies utilizing an extra inductor or coupled inductor alongside an extra power switch, offering one more degree of freedom are also developed, analyzed in their various operational states, and simulated in this paper. Experimental validation of the main topology, operating at 300 W and 50 kHz while stepping up 30 V to 380 V, confirms the provided analyses and proper practical performance.
This paper proposes a novel high step-up DC–DC converter topology featuring two synchronously controlled power switches driven by identical gate signals, thereby simplifying the control circuit. The proposed converter (PC) employs an input inductor to ensure continuous input current and a three-winding coupled inductor to achieve ultra-high voltage conversion gain. In addition, a voltage-multiplier cell is incorporated to further enhance the output voltage gain (VG). A passive-clamp circuit is utilized to recycle leakage energy, reduce voltage spikes, and improve overall efficiency. The converter is analyzed under both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), including the derivation of VG characteristics and CCM/DCM boundary conditions. A comprehensive theoretical investigation is presented, covering steady-state operation, VG, voltage and current stresses of semiconductor devices, component design considerations, power-loss analysis, small-signal modeling, control design, and dynamic response characteristics. Compared with recently reported high step-up converters, the proposed topology achieves an improved trade-off among VG, switch stress, magnetic complexity, and component count through the coordinated integration of the coupled-inductor structure, voltage-multiplier cell, and passive-clamp circuit. To validate the theoretical analysis, a 200 W laboratory prototype with a 24 V input and 400 V output was designed and implemented in both simulation and hardware. Experimental results demonstrate a peak efficiency of 96.7% at 40% load and 95.7% at full load, confirming high efficiency over a wide operating range. These results verify the effectiveness and suitability of the PC for renewable-energy and high step-up power-conversion applications.
Thai Anh Au Tran, Kim-Anh Nguyen, Xuan Khanh Ho et al.· Engineering Research Express· 0 citations
This paper introduces a new non-isolated step-up DC-DC converter based on a switched-capacitor-inductor (SCI) network that achieves high voltage gain at modest duty cycles. The proposed topology is distinguished by several simultaneous merits: low voltage stress on all power switches and diodes, a common ground between the input and output ports, continuous input current, and a superior gain-per-component ratio with respect to inductors, capacitors, and diodes. Thanks to the reduced semiconductor voltage stress, switching losses are mitigated, and the converter can employ lower-voltage active devices, which are inherently more efficient and cost-effective. The converter also features an inherently modular multi-stage structure, allowing it to scale to higher voltage and power levels without proportionally increasing semiconductor stress, which is an advantage over conventional quadratic or coupled-inductor-based high-gain designs. The paper presents a comprehensive steady-state analysis in both continuous (CCM) and discontinuous (DCM) conduction modes, derives the voltage gain and component stresses, and provides a detailed comparative evaluation against state-of-the-art step-up topologies in terms of voltage gain, semiconductor stress, component count, and efficiency. A 400 W laboratory prototype with 48 V input and 400 V output, operating at 25 kHz, was built and tested. Experimental results confirm the theoretical analysis and demonstrate a measured efficiency of 94.9%.
M. Yavari, A. Salemnia, Hamid Javadi et al.· Scientific Reports· 0 citations
With the continuous advancement of the “carbon peaking and carbon neutrality” goals, grid-connected renewable energy generation technologies have developed rapidly, among which high step-up DC–DC converters have become a key enabling component. Based on the cascaded structure of Buck–Boost and Boost converters, this paper introduces an improved voltage-lift unit and proposes a novel high step-up DC–DC converter with low device voltage stress through topology reconfiguration and coupled design. For the proposed topology, the operating modes and energy transfer mechanisms are systematically analyzed, key electrical parameters are derived, and the voltage stresses of switches, diodes, and capacitors are quantitatively evaluated. Furthermore, the proposed converter is compared with the conventional Boost converter, the cascaded Buck–Boost/Boost converter, and the improved voltage-lift Boost converter in terms of voltage gain and device stress characteristics. The results demonstrate that the proposed topology achieves a high voltage gain while significantly reducing the voltage stress on switching devices and energy storage components, thereby reducing conduction and switching losses, improving system efficiency and power density, and showing promising potential for practical applications.
Unknown authors· European Conference on Elect...· 0 citations
This article introduces a novel ultra-high voltage gain DC-DC converter with a low component count, designed for renewable energy applications. In the presented topology, a three-winding coupled-inductor (TWCI) and a switched-capacitor network are embedded within a classic quadratic boost converter. This arrangement yields high voltage gain, ensures continuous low-ripple input current, and preserves a common ground between the source and the load. Due to its trans-inverse feature, the circuit achieves ultra-high voltage gain even with a very low turns ratio in the TWCI. The topology also features current sharing between the TWCI and the main power switch, which significantly reduces power losses in the main power switch and coupled-inductor device. To limit voltage stresses on the active switches, the circuit integrates two passive regenerative clamp circuits, with the switches themselves operated using simultaneous switching patterns. The paper provides detailed steady-state analysis, power loss calculations, comparative evaluation, and design considerations. Finally, a laboratory prototype rated at 200 W has been implemented to verify the theoretical analysis, achieving a very high voltage conversion from 20 V input to 400 V output.
By integrating a three-winding coupled inductor (TWCI) with voltage multiplier cells, this study proposes a quadratic DC-DC converter that achieves ultra-high voltage gain while maintaining continuous input current and a common ground. The proposed coupled-inductor topology is specifically engineered to minimize both voltage and current stresses across all circuit components, thereby enhancing overall performance and enabling potential cost reductions. Enhanced design flexibility is a key feature of the proposed configuration, particularly because the secondary winding of the TWCI operates in a semi-trans-inverse manner, allowing high voltage gains to be realized even with a very low turns ratio. Regenerative passive clamp circuits are incorporated to recover the leakage energy of the TWCI and to limit voltage stresses on the active switches, which are driven with simultaneous switching patterns. The converter's vertical structure further alleviates semiconductor voltage stress, while intrinsic current sharing between the TWCI and the input inductor substantially reduces power dissipation in the main power components. Additionally, turn-off switching losses of both active switches are minimized via a quasi-resonant cell. The paper presents a comprehensive steady-state analysis, detailed power loss evaluation, a comparative study with existing topologies, and key design guidelines. All theoretical contributions are conclusively validated through experimental results obtained from a 200 W hardware prototype, converting a 25 V input to a 400 V output.
Mohammed Jawad Kadhim, M. Moazzami, G. Shahgholian et al.· Scientific Reports· 0 citations
This study proposes a novel quadratic DC–DC buck–boost converter topology specifically designed for integration with renewable energy sources, such as photovoltaic systems. Owing to its quadratic voltage conversion characteristic, the proposed converter provides enhanced step‐up and step‐down capabilities compared to conventional buck–boost converters, particularly when operating under duty cycle conditions far from 50%. A critical review of existing quadratic buck–boost converter topologies indicates that voltage stress reduction is often achieved only partially, either on the MOSFET or on the diode, while the remaining device is subjected to high voltage stress, especially during boost mode operation at high duty cycles. To overcome these limitations, the proposed topology employs only two auxiliary capacitors to realize quadratic voltage gain while simultaneously maintaining low voltage stress on both the MOSFET and the diode over a wide operating range. This structural feature significantly reduces conduction and switching losses, thereby improving overall efficiency. In addition, the converter delivers a noninverting output voltage with a common ground reference between the input and output, facilitating seamless integration into unipolar systems. The proposed converter also ensures continuous current at both input and output ports, which is particularly advantageous for applications requiring stable power profiles. Notably, the converter achieves a unitary voltage gain at a duty cycle of 0.5 and offers a wide voltage conversion range in both buck and boost operating modes. A comprehensive mathematical analysis of the converter is presented, and the accuracy of the analytical results is validated through experimental studies, demonstrating close agreement between theoretical predictions and measured performance.
Barış Çavuş· International journal of cir...· 0 citations
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