Interleaved Ultra-High Step-Up DC-DC Converters With Extendable Voltage Gains and ZVS Performance

Abstract

This paper introduces eight novel interleaved non-isolated dc-dc converters with ultra-high step-up and zero voltage switching (ZVS) capabilities for renewable energy systems. To increase the voltage gain, the proposed converters benefit coupled inductors, high-frequency (HF) transformer, and voltage multiplier (VM) techniques. In comparison to other converters, which just benefit coupled inductors or HF transformers, these combinations of the techniques make an additional degree of freedom to achieve high voltage gains (more than 25 without extreme duty cycle). Besides, two active clamp circuits, including two stages of switch-capacitor VM cells, not only increase the voltage gain of the proposed converters but also act as an auxiliary circuit to provide ZVS. Moreover, the stored energy in the leakage inductances is absorbed and passed to the output by the clamp capacitors. The input current ripple is reduced by applying the interleaved technique. The voltage stress es across the power switches are clamped to lower values and can be controlled by the turn ratios of the coupled inductors and the HF transformer. The theoretical performance of the proposed converters is fully explained. Also, the proposed converters are compared with more than twenty latest interleaved high step-up and ultra-high step-up dc-dc converters. Finally, a 1 kW, 20 V/500 V laboratory prototype is built to prove the advantages of the proposed converters.INDEX TERMS Interleaved structure, dc-dc converter, ultra-high step-up converter, zero-voltage switching

Performance improvement of a zero‐voltage switching interleaved high step‐up DC–DC converter with low‐voltage stresses

“…It is concluded that the proposed converter successfully improved the state‐of‐the‐art especially [37]. Although the proposed converter of [33] excellences the proposed converter in some case, however it utilizes four more components.…”

“…In the converters with CIs and/or BIT, the small auxiliary inductor can be replaced with the leakage inductance of the magnetic devices. The leakage inductance along with the active clamp circuit provides ZVS performance for the main and clamp switches, through whole switching cycle [29][30][31][32][33]. The soft-switching operation is accomplished by a cell consisting of an auxiliary CI without participation in voltage gain, two auxiliary MOSFETs and a capacitor connected between the main MOSFETs' legs of the interleaved boost modules and the output stage in [34].…”

Novel Zero-Voltage Zero-Current Transition Buck Converter With Minimal Impact of Active Auxiliary Cell on Overall Dynamics

“…This controller enjoys the advantages of more freedom in placing the poles and zeros and achieve better stability margin compared to conventional PI controller. Design of k-factor based type III controllers with optimum performance and faster transient response have been presented in [16][17][18].Method of Pole placement for controller design using all accessible state variables are used in [19].PI controller along with sigma delta modulator has been implemented for the converter presented in [20] [24].Restrictions of dominant pole placement (DPP) method of controller is analysed in [21].The control scheme adopted in [23] shapes the auxiliary inductor current for the improvement of dynamic response. Soft-switching quasi-resonant converters (QRC) use active and/or passive resonant networks, in addition to basic components of normal pulse-width-modulation (PWM) converters.…”

A new interleaved high step‐up soft switching converter with simple auxiliary circuit and reduced voltage stress

“…However, in such converters, MOSFETs are not switched under ZVS, increasing switching losses [14,15]. Zero voltage transition (ZVT), active clamp, and resonance techniques can remove MOSFETs switching and capacitive turn-on losses [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The proposed ZVT cell in [16] is compact, low cost, and efficient and can improve the current imbalance between interleaved phases.…”

“…However, the voltage stress of the auxiliary switches is higher than the output voltage, which increases this converter's capacitance and conductive losses. The proposed active auxiliary cells in [25] provide ZVS conditions for all power switches, absorb the leakages' energy, and increase the output voltage. However, increasing VM cells achieves ultra-large gain, which increases the number of components and converter cost.…”