Simulation model for DRSSTC

profdc9, Wed May 04 2016, 12:32AM

Hello,

I am trying to understand better how a DRSSTC works. To do this, I built a simulation of a DRSSTC for the Qucs circuit simulator (free ). I think the model basically works. Of course I don't have models for everything including gate drivers, which right now are implemented using simple buffers, but it includes:

Runs off a single 15 volt supply
Uses open-collector comparators (LM319)
Uses JK flip flop with enable/disable (CD4027BE)
Uses CMOS nand gate (CD4093B)
Half Bridge - two MOSFETS (IRFP460 is what I have models for)
Gate Driver Transformer
LC series circuit primary (250 kHz oscillation frequency)
Current feedback transformer
Current feedback for resonant oscillation using comparators and flip-flops
- This generate a short clock pulse when the current in the tank circuit cross through zero, either positive or negative transition
- Deliberately designed to avoid using comparator feedback hysteresis to achieve minimum latency. Uses a window comparator instead.
Start/stop interrupter circuit and enable/disable
- Turns off IGBT/MOSFET at zero current to avoid latchup

The second circuit is the lockout pulse circuit, which turns the interrupter on and off. This generates a pulse for a fixed interval, but does not allow another pulse to be generated for a much longer interval, so that the duty cycle of the DRSSTC is not exceeded. The idea is that a pulse source, either a fixed frequency clock or a musical pulse source could be attached here.

Unfortunately due to simulation limitations, I can't simulate the two circuits together, but they seem to work individually.

There is currently no overcurrent detection modeled, but that shouldn't be too difficult to add. Gate drivers could include UCC37321/UCC37322 or something more substantial if required.

Anyways, I thought I would share the model. If any of you decide to download qucs and play with it, let me know.

Dan


]qucs-drsstc-tesla-coil-model.zip[/file]

I forgot to include the screenshots of the schematics. Here they are and the simulation results.

Dan