RESONANT CAVITY SWITCHING APPARATUS AND CONTROL METHOD FOR LLC RESONANT CONVERTER

摘要

Disclosed are a resonant cavity switching apparatus and control method for an LLC resonant converter. The apparatus comprises: an input rectifier filter, an input inverter bridge, a first resonant cavity, a second resonant cavity, a handover apparatus, a first output rectifier filter apparatus and a second output rectifier filter apparatus. The circuit of the present invention can enable, by means of the handover apparatus, an LLC converter to work in different resonant cavities. When the handover apparatus is turned on, only the first resonant cavity participates in resonance, and therefore, only a first output rectifier bridge can perform power transmission. When the handover switch is turned off, the first resonant cavity and the second resonant cavity are connected in series so as to work and resonate together; and in this case, the first output rectifier bridge and a second output rectifier bridge perform power transmission at the same time, and output power can be doubled under the condition that parameters of the two resonant cavities are the same. Thus, the gain range of the LLC converter is widened, and the problem of it not being possible for the LLC resonant converter to work in a wide gain range is solved.