Application of synchronous motors in pulp and paper industry

Large synchronous motors in rating of 15 000 hp and higher have been used in Thermal Mechanical Pulp (TMP) plants. Applications to Jordans, grinders and vacuum pumps drives are also common. As compared to an induction motor, a synchronous motor can be designed more specifically for the required torque, power factor and starting kVA requirements. The paper discusses the motor operating and starting characteristics, starting methods and excitation systems with specific applications of chipper and TMP refiner motors. A transient stability analysis on starting a 20 000 hp synchronous motor is presented. An application analysis should consider mutually interacting characteristics of the motor, load and the power supply system.