I was looking at emily's file and noticed the current in series components, C1 and L1 are OK at the beginning but not for the thousands of Amp spikes in C1. I am guessing that this may be an ill conditioned simulation somehow, so is that why the currents in these series components different ??
boB
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--- In LTspice@..., "Rick" <sawreyrw@...> wrote:
--- In LTspice@..., "emily_gaopeng" <emily_gaopeng@> wrote:
hello, everyone, I am doing a simulation about Series-parallel LLC
resonance dc to dc converter. I choose the switching frequency as
100kHZ. In the simulation, the current going through the load is
extremely low. I checked everything, and all the switches and diodes
works fine. I could not figure out why. Any one has done this
simulation before, would you mind giving me some hints?
I have uploaded the file LLC series-parallel resonance dc to dc
converter.asc
Thank you so much
Emily,
This is off topic, but I'll give you a couple of hints anyway.
1. Since each side of the bridge is on exactly half the time the average voltage from point A to B is zero. This is why the output is essentially zero.
2. Your bridge is OK, but you should really have a small dead time for each switching event, and the duty cycle should not be 50%. Without the dead time you may get huge shoot through currents; take a look at the currents through the switches. You need separate drive signals for each pair of switches.
3. I'm not too familiar with this particular circuit, but I don't think it is suited for a full bridge. I could be wrong.
4. Helmut already told you the frequency is 100 MHz, not 100 KHz.
Rick
boB G