hi

attached are the circuits I have created.

I am trying to run a test for ABB's HVDC circuit breaker and for Alstom's HVDC circuit breaker. I developed a model for the HVDC using just an IGBT as the circuit breaker and got the expected results however when I replace IGBT with either the Alstom or ABB design that I have created on SIMULINK the simulation takes for ever to load and then crashes.

for the ABB model the aux IGBT has:

internal R 0.2ohms
snubber R 1e3
snubber C 0.0001

the IGBT stacks are 100 4.5kV IGBTs in series

there is a 320kV supply voltage and a load RL branch of 318ohms with a 1000A steady state current.

does anyone have any ideas?