--There are several approaches to nonisolated dc-dc conversion for use when the input varies above and below the output. Among these are the SEPIC, buck-boost and others involving a combination of buck and boost circuits. This paper contains an analysis of four types, with particular attention to the efficiency in a typical application.

DC microgrids have been quite popular in recent times. The operational challenges like control and energy management of the renewable-driven standalone an interest research. This paper presents a bidirectional quasi Z-source DC-DC converter (BQZSDC). topology has developed based on conventional buck-boost type converter, it interfaces storage system common bus. challenge, however, lies effectiv...

Received Jan 8, 2018 Revised Mar 23, 2018 Accepted Apr 11, 2018 Distributed energy source based electricity generation is an essential factor for the economic growth and development of a country. The photovoltaic, fuel cell and battery based power generation offer a high voltage gain. The DC-DC CUK converter based on both buck and boost mode of operation is proposed for high gain dc link voltag...

In this paper, we derive the discrete-time model for the power-factor-correction (PFC) buck-boost converter in terms of a stroboscopic switching map. Fast-scale instability is analysed through a fold diagram, which exposes the periodicity of the operation as well as the locations of the critical phase angles of the line voltage at which instability begins to occur along a half-line cycle. The a...

A6s t~ac t A flyback dc-dc converter is obtained from t h e conventional buck-boost converter by replacing t h e inductor with an isolation transformer. A transformer in the flyback converter is used to achieve a d c isolation between t h e input and the o u t p u t of t h e converter. This paper presents dc and small-signal circuit models for t h e flyback converter for continuous conduction m...

To raise the utilization ratio of lithium-ion battery in portable devices, a novel green-switch controller IC is proposed to constitute a 4-switch cascade buck–boost prototype, which is capable of outputting non-inverting step down and step up voltages. According to the relations between the input and output voltages through duty ratio, a finite state machine automatically determines the work m...

Abstract: The main objective of this paper was to study a bidirectional direct current to direct current converter (BDC) topology with a high voltage conversion ratio for electric vehicle (EV) batteries connected to a dc-microgrid system. In this study, an unregulated level converter (ULC) cascaded with a two-phase interleaved buck-boost charge-pump converter (IBCPC) is introduced to achieve a ...

This paper presents an electric drive system whose motor is connected to a battery by means of a buck DC/DC converter. This motor is further connected to an ultracapacitor by means of a boost DC/DC converter. First, operation and break processes are studied when the converters are switched off as well as when they are switched on in current limitation mode. Then, a comparative analysis of the r...

Buck-boost DC–DC converters are useful as DC grid interfaces for renewable energy resources. In the classical buck-boost converter, output voltages smaller than input voltage (the buck region) observed duty cycles between 0 and 0.5. Several recent have been designed to present higher gains. Nevertheless, those topologies show a reduced duty-cycle range, leading in region, thus require use of ve...