A bit of a general question here! In resonant converters, the power is typically transferred from the source to the load. However, is it possible to transfer power bi-directionally such as within a dual-active-bridge?
In some applications where the load current can transition from full load to zero load, and no energy is transferred to the secondary side through the transformer - where does the resonant energy held within the inductors and capacitors go? Does it just gradually dissipate, or is it held in them until the load is connected again? Is there a way to transfer this resonant tank energy back to the source, or is this just defeating the purpose of a resonant converter?
At the moment, I have a buck regulated resonant half bridge converter. However when the load current transitions from full load to zero load, the current in the resonant tank goes to zero and no power is transferred to the secondary side. But what I don't understand is what happens to the energy stored within the tank at this instant? Could the buck be replaced with something else which is bi-directional to recover the energy back to the source? The current through the buck converter also (for some reason?) drops to zero amps, and the voltage on the capacitor rapdily decays. I could place a very large cap here to hold the charge but I would like to avoid that.
Topology attached.
In some applications where the load current can transition from full load to zero load, and no energy is transferred to the secondary side through the transformer - where does the resonant energy held within the inductors and capacitors go? Does it just gradually dissipate, or is it held in them until the load is connected again? Is there a way to transfer this resonant tank energy back to the source, or is this just defeating the purpose of a resonant converter?
At the moment, I have a buck regulated resonant half bridge converter. However when the load current transitions from full load to zero load, the current in the resonant tank goes to zero and no power is transferred to the secondary side. But what I don't understand is what happens to the energy stored within the tank at this instant? Could the buck be replaced with something else which is bi-directional to recover the energy back to the source? The current through the buck converter also (for some reason?) drops to zero amps, and the voltage on the capacitor rapdily decays. I could place a very large cap here to hold the charge but I would like to avoid that.
Topology attached.
Attachments
-
54.6 KB Views: 18