How to resolve the Non Convergence issue while doing bolted fault at POI ?

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I'm doing PRC029 for which i need to do bolted fault at POI but whenever the POI voltage goes below 0.1pu, the network starts to non converge at multiple time instance and i'm observing very high frequency spikes due to which my freq protection setting is applied and the inverter is tripped. I have tried many methods like decreasing the acc factor to 0.7 and lower in REGCA model, changing the Lvnpt values, changing R&X in steady state model etc. I know this issue is inherent in the REGCA model due to which i also tried with REGCC model but with REGCC, I'm not facing issue. Any leads would be helpful.