Novel technique for bidirectional series‐resonant DC/DC converter in discontinuous mode

Abstract

This study analyses a novel technique for obtaining a voltage conversion ratio greater than one in a bidirectional seriesresonant DC/DC converter (SRC). The converter works in a discontinuous mode: it transfers energy in packets, but it also accumulates some packets in order to raise the output voltage. This study presents a comprehensive theoretical analysis for the two modes: the step-down mode (common mode) and the novel step-up mode. The converter transfers energy during fixed time intervals (called states), and it is also able to accumulate energy in a novel state called the accumulation state. With this, the circuit can achieve a voltage conversion ratio of up to two. In addition, a design methodology is presented, and it is validated in the design of a high-current bidirectional DC/DC converter for battery applications. The results of the voltage conversion ratio and efficiency measurement are presented along with a comparison with an resonant LLC converter. The converter reaches an efficiency rate of 91% and the voltage conversion ratio varies from 0.8 to 1.22 at maximum power. Using this novel technique, the SRC can now be used in a bidirectional DC/DC converter applied to energy storage devices, such as batteries or supercapacitors.

Frequency response analysis for bidirectional series‐resonant DC/DC converter in discontinuous mode

“…In order to present the method, the step-down mode will be analysed first. The detail of its waveforms and operation cases is fully explained in [14], which includes the DC analysis and consists of three different cases: Cases 1, 2 and 3. In this paper, the small-signal behaviour is presented, which has three steps.…”

“…The source port delivers energy packets to the output port, and the procedure for adjusting the output values consists of controlling the time between each packet [11][12][13]. Recently, a method that allows the bidirectional SRC to work as a step-up or step-down converter was presented [14], but there is not enough information about the frequency response of this converter working in the step-up mode. This paper presents a novel analysis method in order to obtain the small-signal transfer function of a SRC working in a DCM.…”

Studies on a Hybrid Full-Bridge/Half-Bridge Bidirectional CLTC Multi-Resonant DC-DC Converter with a Digital Synchronous Rectification Strategy

“…As a result, BRDCs are characterized by high efficiency, high power density and low EMI, and are applicable to high frequency applications [9,10]. Among all the BRDCs, the bidirectional series resonant converter (BSRC) is a candidate topology [11][12][13][14][15][16]. All the switches of a BSRC work in either ZVS or ZCS for a wide variation of voltage gains with phase-shift control [13].…”

“…All the switches of a BSRC work in either ZVS or ZCS for a wide variation of voltage gains with phase-shift control [13]. A novel control scheme was developed for BSRC in discontinuous mode [14]. With the accumulation of energy packets to raise output voltage, it is possible to have a gain greater than one.…”

Numerical modelling of PCB planar inductors: impact of 3D modelling on high‐frequency copper loss evaluation

“…The latter also leads to more controllable and predictable parasitic parameters [4]. PMC now can be found in a lot of applications: resonant converters [5,6], gate drivers [7], electromagnetic compatibility filters [8,9], high-voltage or high-current applications [10][11][12][13] for example.…”