During the LVRT fault, the over-excitation is normal as the AVR switched to voltage regulation mode. Depending on the voltage PID setting, the integral accumulation is high so after the fault the PF/kVAR regulation loop may take more or less time to reduce the excitation. This can be improved by the two methods below:
- Reduce the integral part of the voltage loop (e.g divide by 3),
- If not enough, increase the dynamics of the PF/kVAR regulation loop.