Thermal Power Plant Fan Drive Load Distribution Control

This paper presents an approach to pressure/under-pressure and load distribution control of fresh air supply and exhaust fans at thermal power plants, where dual actuators are used. The proposed concept, relative to standard solutions, offers better performance, simplified tuning and start-up, and safer operation in terms of over-current protection. Pressure/under-pressure and load distribution of the two fans by means of flap position relies on two PI pressure controllers, two PI current controllers (when over-current protection is active), and one PD controller for load distribution control between the two drives.