Accurate frequency‐domain analysis and hybrid control method for isolated dual active bridge series resonant DC/DC converters. Issue 11 (14th August 2019)

• Record Type: Journal Article
• Authors: Wang, Shien; Zheng, Zedong; Li, Chi; Xu, Lie; Wang, Kui; Li, Yongdong
• Is Part Of: IET power electronics. Volume 12:Issue 11(2019)
• Page Start: 2932
• Page End: 2941
• Publication Date: 2019-08-14
• Subjects: zero current switching -- frequency‐domain analysis -- bridge circuits -- zero voltage switching -- resonant power convertors -- switching convertors -- DC‐DC power convertors; accurate frequency‐domain analysis -- hybrid control method -- isolated dual active bridge series resonant DC/DC converters -- accurate frequency model -- DABSRC -- conventional first harmonic approximation method -- steady‐state model -- harmonic components -- accurate expression -- precise soft switching criterion -- hybrid control strategy -- wide voltage gain -- load variations -- extended soft switching region -- zero‐voltage‐switching turn‐on at light loads -- power 500.0 W; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2019.0015
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : This study proposes an accurate frequency model of dual active bridge series resonant DC/DC converters (DABSRC). Differing from the conventional first harmonic approximation method, the proposed steady‐state model considers all the harmonic components, which gives an accurate expression of transferred power and resonant current. Based on the proposed model, a precise soft switching criterion was derived, and the soft switching region was extended. On top of that, a hybrid control strategy combining phase shift modulation and frequency modulation was proposed, to achieve soft switching under wide voltage gain and load variations. Thanks to the extended soft switching region, DABSRC can achieve zero‐voltage‐switching turn‐on at light loads, only with a slight increase in switching frequency, hence improving the efficiency a lot. The accurate frequency model and the hybrid control were validated using a 500 W laboratory prototype. The experiment results showed accurate predictions of the proposed model and significant improvements in light load efficiency over a wide range of input voltages.