DC-DC High-Voltage-Gain Converters with Low Count of Switches and Common Ground

This paper presents a new concept and research results of DC-DC high-voltage-gain, high-frequency step-up resonant converters. The proposed topologies are optimized towards minimizing the number of switches and improvements in efficiency. Another relevant advantage of such type of converters is that they have a common input and output negative point. The proposed converters are based on the resonant switched-capacitor voltage multiplier circuit, and that is why they are compared with a classic converter from this family. The included results show the operating principle, possible switching methods with the consideration of their impact on the voltage gain level, as well as the voltage and current ripples. The operating concepts and analytical calculations are confirmed by simulation and experimental results

GaN-Based DC-DC Resonant Boost Converter with Very High Efficiency and Voltage Gain Control

This paper presents a concept for the operation of a resonant DC–DC switched-capacitor converter with very high efficiency and output voltage regulation. In its basic concept, such a converter operates as a switched-capacitor voltage doubler (SCVD) in the Zero Current Switching (ZCS) mode with a constant output voltage. The proposed methods of switching allow for the switched-capacitor (SC) converter output voltage regulation, and improve its efficiency by the operation with Zero Voltage Switching (ZVS). In this paper, various switching patterns are proposed to achieve high efficiency and the output voltage control by frequency or duty cycle regulation. Some examples of the application of the proposed switching patterns are presented: in current control at the start-up of the converter, in a bi-directional converter, and in a modular cascaded system. The paper also presents an analytical model as well as the relationships between the switching frequency, voltage ratio and efficiency. Further, it demonstrates the experimental verification of the waveforms, voltage ratios, as well as efficiency. The proposed experimental setup achieved a maximum efficiency of 99.228%. The implementation of the proposed switching patterns with the ZVS operation along with the GaN-based (Gallium Nitride) design, with a planar choke, leads to a high-efficiency and low-volume solution for the SCVD converter and is competitive with the switch-mode step-up converters

All-Bootstrap Gate-Driver Supply System for a High-Voltage-Gain Resonant DC-DC Converter with Seven Switches

This paper presents the concept and implementation of an electronic system for a switched-capacitor DC-DC converter with high voltage gain. The converter consists of seven switches, five of which being controlled like high-side type. This paper presents a non-typical bootstrap-based gate-driver system so that the converter can run using a single voltage source. The converter requires a special switching pattern to drive seven switches in a steady state and also during the start-up of the converter and the regulation of the output voltage. Therefore, an FPGA-based digital control system is used with various switching algorithms and protection functions implemented. The presented converter is an autonomic device that taps the energy from the main input. Therefore, the electronic system of the converter is equipped with a self-supply system with a wide range of the input voltage. The parameters of the converter such as voltage gain, voltages and power ranges can be scalable for prospective applications with the proposed control system

A Cost-Effective Resonant Switched-Capacitor DC-DC Boost Converter – Experimental Results and Feasibility Model

This paper presents the results of experimental research of a resonant switched capacitor voltage multiplier in a cost-effective topology (CESCVM) with a limited number of active switches. In the charging mode of the switched capacitors, the converter utilizes only one active switch and a required number of diodes. Therefore, the cost of the converter is decreased as compared with that of a classical SCVM converter, owing to a lower number of switches and gate driver circuits, as well as a smaller PCB area. Moreover, the CESCVM has simpler control circuits and higher reliability. This paper presents the original experimental results of the operation of the CESCVM converter. A concept of the bootstrap supply of gate drivers of the flying switches is also examined

Single-source three-phase switched-capacitor-based MLI

This article proposes a novel three-phase inverter based on the concept of switched capacitors (SCs), which uses a single DC source. A three-phase, seven-level line-to-line output voltage waveform is synthesised by the proposed topology, which includes eight switches, two capacitors, and one diode per phase leg. The proposed topology offers advantages in terms of inherent voltage gain, lower voltage stresses on power switches, and a reduced number of switching components. Additionally, the switched capacitors are self-balanced, thereby eliminating the need for a separate balancing circuit. The proposed structure and its operating principle, the self-balancing mechanism of the capacitors, and the control strategy are all thoroughly explained in the article. The proposed topology has also been compared with some recent SC topologies. Lastly, the proposed topology has been shown to be feasible through simulation and experimentation