The Research Of Series Resonant Bi-Directional DC/DC Converter

As a kind of technology in the conversion of electrical energy, bi-directional DC/DC converter comes out with its applications. In order to meet more and more requirements in the social activities and industrial production, bi-directional DC/DC converter has been developing very fast. As a result of the advantages such as higher frequency and smaller volume brought by the soft-switching technology, the research on bi-directional DC/DC converter has been focused on realizing the high frequency characteristics with the soft-switching technology. Based on the soft-switching property in series resonant converter, this paper proposes a bi-directional DC/DC converter which ensures that the power can transfer in either direction as well as the implementation of soft-switching by improving control scheme.First of all, the topology of series resonant bi-directional DC/DC converter is obtained by using the construction method for bi-directional DC/DC converter. After that, the operational principle and the realization manner of soft-switching on series resonant DC/DC converter are analyzed under different switching-frequency ranges. And then this paper introduces the control schemes employed in series resonant DC/DC converter, and analyzes the self-sustained phase shift modulation control technique emphatically, including its control principle, operational property, realization manner and prerequisite of soft-switching. Finally, the simulations about self-sustained phase shift modulation control is done to prove the theoretical analysis validated.Based on all the above as well as the analysis on the operational property of series resonant tank and the topology of full-bridge, this paper presents a new control scheme which can make series resonant bi-directional DC/DC converter operate under backward-mode. Its control principle, operational property, realization manner and prerequisite of soft-switching were analyzed in detail. Furthermore, this new control scheme is realized by improving the circuit of self-sustained phase shift modulation control and proved validated via simulations.Finally, a series resonant bi-directional DC/DC converter is built. The forward-mode and backward-mode experiments together with the soft-switching property are finished on this prototype. By the results, the correctness and feasibility are demonstrated adequately.