ZVS Auxiliary Circuit for a 10 kW Unregulated LLC Full-Bridge Operating at Resonant Frequency for Aircraft Application

Bouvier, Y.; Serrano, Diego; Borović, Uroš; Moreno, Gonzalo; Vasić, Miroslav; Oliver, J. A.; Alou, P.; Cobos, J.A.; Carmena, Jorge

doi:10.3390/en12101850

Cited by 9 publications

(4 citation statements)

References 26 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Its main task is to minimise the turn-off losses of the transistor T 5 , absorb the energy of the transformer leakage inductance and recover the absorbed energy to the load. Compared to other similar designs [9][10][11][12]16,18], the proposed turn-off snubber uses only one capacitor and utilizes parasitic elements of the circuit.…”

Section: Time Waveforms Of the Proposed Convertermentioning

confidence: 99%

“…The PS-PWM ZVS full bridge converter is prone to losing soft-switching at light loads, which is one of its main drawbacks. On the other hand, the resonant converters offer ZVS and good efficiency at light loads, but require variable switching frequency, which can limit or complicate their application [17][18][19][20]. Another way to maintain ZVS for a wide load range is to utilise load adaptive converters [21,22].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Soft-Switching Full-Bridge DC-DC Converter with Energy Recovery Capacitor Snubber

et al. 2023

View full text Add to dashboard Cite

This paper describes a high-frequency soft-switching dc-dc converter with a simple energy recovery capacitor snubber on the secondary side. The presented dc-dc full-bridge converter with the energy recovery snubber removes the main drawbacks of the classic Phase Shifted PWM (PS-PWM) dc-dc converter, e.g., the circulating current flowing during the free-wheeling interval and dependency of the soft switching on the load current. The converter utilizes a full-bridge topology with pulse-width modulation and a centre-tapped full-wave controlled rectifier with one active switch. The zero-voltage switching on the primary side is ensured by utilising only the magnetizing current of the high-frequency transformer, and thus is load-independent. The proposed energy recovery snubber is described in detailed time waveforms of the converter and verified by simulation. The control algorithm also removes the circulating current, which is typical for PS-PWM converters. The soft-switching of the secondary side transistor is achieved by a simple capacitor snubber with an energy-recovery circuit connected to the output of the dc-dc converter. The principle of operation is verified by measurements on a 2 kW, 50 kHz laboratory model of the proposed dc-dc converter.

show abstract

Section: Time Waveforms Of the Proposed Convertermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Soft-Switching Full-Bridge DC-DC Converter with Energy Recovery Capacitor Snubber

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The leakage inductance has a significant influence on the operation of the converter and the specified value is usually well achieved in the MFT development process. In the LLC resonant dc-dc (LLC) converter [1,16,17], the magnetizing inductance has a significant effect on the zero voltage switching (ZVS) [18][19][20], but it may be difficult to achieve within reasonable error margins [21]. The maximum value of the magnetizing inductance should take into account the drain-source capacitance C ds of the MOSFET (or other power semiconductor switch).…”

Section: Mft Vsc1 Vsc2mentioning

confidence: 99%

Effective Permeability of Multi Air Gap Ferrite Core 3-Phase Medium Frequency Transformer in Isolated DC-DC Converters

et al. 2020

View full text Add to dashboard Cite

The magnetizing inductance of the medium frequency transformer (MFT) impacts the performance of the isolated dc-dc power converters. The ferrite material is considered for high power transformers but it requires an assembly of type “I” cores resulting in a multi air gap structure of the magnetic core. The authors claim that the multiple air gaps are randomly distributed and that the average air gap length is unpredictable at the industrial design stage. As a consequence, the required effective magnetic permeability and the magnetizing inductance are difficult to achieve within reasonable error margins. This article presents the measurements of the equivalent B(H) and the equivalent magnetic permeability of two three-phase MFT prototypes. The measured equivalent B(H) is used in an FEM simulation and compared against a no load test of a 100 kW isolated dc-dc converter showing a good fit within a 10% error. Further analysis leads to the demonstration that the equivalent magnetic permeability and the average air gap length are nonlinear functions of the number of air gaps. The proposed exponential scaling function enables rapid estimation of the magnetizing inductance based on the ferrite material datasheet only.

show abstract

“…Research was also performed in the area of the PSFB with a voltage doubler [16], and even though this topology is well-suited for high-voltage applications, it lacks in power throughput. Many analyses for resonant variants of PSFB were conducted [17][18][19], including the development of an accurate output voltage formula reported for the LLC Full-Bridge topology [20]. As for the four-diode PSFB, only non-closed-form expressions have been provided, such as the ones in [2], which, in addition, do not consider the impact of all eight design parameters.…”

Section: Introductionmentioning

confidence: 99%

Closed-Form Formulas for Automated Design of SiC-Based Phase-Shifted Full Bridge Converters in Charger Applications

et al. 2021

View full text Add to dashboard Cite

Phase-Shifted Full Bridge (PSFB) topology in its four-diode variant is the choice with the lowest part count in applications that demand high power, high voltage, and galvanic isolation, such as in Electric Vehicle (EV) chargers. Even though the topology is prevalent in power electronics applications, no single, unified analytical model has been proposed for the design process of four-diode PSFB converters. As a result, engineers must rely on simulations and empirical results obtained from previously built converters when selecting components to properly match the DC source voltage level with the DC load voltage requirements. In this work, the authors provide a design-oriented analysis approach for obtaining the output voltage and semiconductor current values, ready for implementation in a spreadsheet- or MATLAB-type software to automate design optimization. The proposed formulas account for all the first-order nonlinear dependencies by considering the impact of each of the following eight design parameters: DC-link voltage, load resistance, phase-shift ratio, switching frequency, transformer turns ratio, magnetizing inductance, series inductance, and output inductance. The results are verified through experiments at the power level of 10 kW and the DC-link voltage level of 800 V by using a grid simulator and a SiC-based two-level Active Front End (AFE) with a DC–DC stage based on the PSFB topology. The accuracy of the output voltage formula is determined to be around 99.6% in experiments and 100.0% in simulations. Based on this exact model, an automated design procedure for high-power high-voltage SiC-based PSFB converters is developed. By providing the desired DC-link voltage, output voltage, output power, output current ripple factor, maximum temperatures, and semiconductor and heatsink databases, the algorithm calculates a set of feasible designs and points to the one with the lowest semiconductor losses, dimensions, or cost.

show abstract

ZVS Auxiliary Circuit for a 10 kW Unregulated LLC Full-Bridge Operating at Resonant Frequency for Aircraft Application

Cited by 9 publications

References 26 publications

Soft-Switching Full-Bridge DC-DC Converter with Energy Recovery Capacitor Snubber

Soft-Switching Full-Bridge DC-DC Converter with Energy Recovery Capacitor Snubber

Effective Permeability of Multi Air Gap Ferrite Core 3-Phase Medium Frequency Transformer in Isolated DC-DC Converters

Closed-Form Formulas for Automated Design of SiC-Based Phase-Shifted Full Bridge Converters in Charger Applications

Contact Info

Product

Resources

About