Non‐isolated high step‐up DC–DC converter based on coupled inductors, diode‐capacitor networks, and voltage multiplier cells

Abstract

This work presents a non‐isolated DC–DC boost converter employing coupled inductors, a diode‐capacitor network, and a voltage multiplier cell (VMC). This converter allows extending the conversion ratio not only by increasing the turns ratio of the coupled inductor, but also by adding more networks and VMCs, resulting in a more flexible design approach. Unlike most coupled‐inductor‐based boost‐type converters reported in the literature, the topology presents an output stage whose current is non‐pulsating, which leads to reduced electromagnetic interference (EMI) levels. Other prominent advantages include the fact that the input current is non‐pulsating with low high‐frequency ripple, as well as the operation of the switch and output diode under soft‐switching condition. Experimental results obtained from a 200‐W prototype are presented and discussed to validate the theoretical assumptions, also showing that the converter has high efficiency over a wide load range.

Theoretical and experimental evaluation of SEPIC‐based DC–DC converters with two‐winding and three‐winding coupled inductors

“…By combining the coupled inductor with some techniques, the voltage level can be increased significantly. These techniques include voltage lifting, 14,15 voltage multiplier, 16–20 switched capacitor, 21,22 and switched inductor 23 …”

“…By increasing the inductor magnetization current, the core losses increase, and we need a larger core 25–26 . Also if the structure of the converter is in a way that the primary winding is directly connected to the input source, the input current of the converter will be in pulsed waveform, and it needs a larger filter at its input 9,14–17,21 …”

“…[9][10][11][12][13] By combining the coupled inductor with some techniques, the voltage level can be increased significantly. These techniques include voltage lifting, 14,15 voltage multiplier, [16][17][18][19][20] switched capacitor, 21,22 and switched inductor. 23 Disadvantages of the coupled inductor include large inductor magnetization current, using half of the B-H curve of core, and increased current ripple at the primary winding.…”

“…[25][26] Also if the structure of the converter is in a way that the primary winding is directly connected to the input source, the input current of the converter will be in pulsed waveform, and it needs a larger filter at its input. 9,[14][15][16][17]21 Recently, researchers are working on developing the new topologies of three-winding coupled inductor converters to increase the converter's voltage gain. [27][28][29][30][31] It is normal that by increasing the number of coils, voltage gain of the converter will be increased, but in the articles based on three-winding coupled inductors that have been published in the past, the inductor size and its core dimensions have not been compared with two-winding structures.…”

High step‐up active switched coupled inductor DC‐DC converter with voltage multiplier

“…Distributed generation is an alternative to the existing global energy system, becoming a promising candidate for the more efficient use of energy, economic‐financial and environmental resources. Several sources can be considered in the scope of distributed generation, such as fuel cells (FC) and the photovoltaic cells (PV) 1–3 . These sources provide a low DC voltage (typically <50 V), so a high step‐up DC‐DC converter is required to increase this low voltage to high output voltage 4 .…”