Exhausting protection control method and system

The invention discloses an exhausting protection control method and system. The method includes the frequency reduction protection mode and the halting protection mode. The system comprises a frequency reduction protection unit and a halting protection unit. According to the exhausting temperature and the change conditions of the exhausting temperature, whether frequency conversion is needed or not is judged, the judgment accuracy is effectively improved, and a plurality of exhausting temperature intervals are designed for the different frequency reduction control so that the best system operation efficiency can be kept when the system safe operation is guaranteed. The exhausting protection control method and system can be widely applied to the field of frequency conversion control.