Single-ended Primary Converter Research Articles

Single-Switch Non-Isolated Resonant DC-DC Converter for Single-Input Dual-Output Applications

This paper describes a new configuration of Cuk and SEPIC (Single-Ended Primary Converter) ZVS-QR (zero-voltage switching quasi-resonant) combination DC-DC converter for bipolar output with a single switch. The proposed topology employs a single ground-referenced power switch, which simplifies the gate drive design with a single L-C resonant network and provides a bipolar output voltage with good regulation, acceptable efficiency and a step-down/up conversion ratio. This configuration provides dual-output voltage by switching the power switch to zero voltage, which is an interesting alternative for many applications where small size, light weight and high power density are very important aspects. In order to verify its performance, a SEPIC–Cuk Combination ZVS-QR prototype with a cost-effective commercial resonant controller was designed and tested. The experimental results show that the proposed combined topology is suitable for Single-Input Dual-Output (SIDO) applications.

DC-DC Converter with Bipolar Output and its Use for Connection of a Distributed Generation System to a Bipolar DC Grid

Background: This work describes the methodology and the basic procedure developed by the patent entitled DC-DC Converter with Bipolar Output and its Use for Connection of a Distributed Generation System to a Bipolar DC Grid. Methods: The invention relates to a DC-DC converter capable of generating bipolar voltage with a suitable novel topology for distributed generation connection to a DC bipolar grid. The proposed topology uses only a power switch, unlike other DC-DC converters which employ two or four switches. Thus the complexity of the converter is reduced. The DC-DC converter with bipolar output has an input for connection to a monopolar DC source and a bipolar output voltage with a positive terminal and a negative terminal. The DC-DC converter can be applied to bipolar DC grids because it allows the connection of a monopolar DC source to such networks. The present invention is especially applicable in the industrial sector and renewable energies. In the first case, because this network type is an alternative to classic electric system, currently of interest special in the industry. In this sector, the proposed converter can control the voltage level and possible unbalances of the DC voltage network. On the other hand, in the renewable energy sector, the proposed scheme enables the connection of generation and storage systems to a bipolar DC network in a way reliably. Result: The proposed topology is a solution for these applications with sufficient guarantees of reliability, quality and performance. Conclusion: An experimental prototype based on a combination of SEPIC (Single Ended Primary Converter) and Cuk converter has been implemented to validate the patented system. Keywords: DC-DC converters, DC microgrids, distributed generation, DC bipolar network, experimental prototype, SE-C4CC.

A Converter for Bipolar DC Link Based on SEPIC-Cuk Combination

This letter describes a new application of single-ended primary converter (SEPIC) and Cuk converter for dc bipolar network. A dc-dc converter configuration based on a combination of both converters is proposed. In the resulting topology, the switching node is shared by the SEPIC and Cuk converter since they have the same instantaneous duty cycle. The main advantage of this topology is that synchronization of various switches is not required and control terminal is connected to ground which simplifies the design of the gate drive. On the other hand, this configuration allows the connection of renewable energy sources to microgrids (MG)-type bipolar dc link and to cover the current needs of new distributed generation units with efficient, economical, and easy way. To verify its performance, a prototype was designed. Experimental results show as this combination of two converter topologies with appropriated modulation schemes are adequate to use in dc MG.