Characteristics and analysis of starting of large synchronous motors

The design of synchronous motors is more flexible as compared with induction motors for tailoring the starting characteristics for specific load requirements. Synchronous motors in rating of 35,000 hp and higher have been used in thermal mechanical pulp (TMP) plants. An analysis of the motor and load starting characteristics, starting methods and impact of starting on power supply system is presented. A successful application should consider mutual interaction between the motor, load and power supply system. The paper discusses this interaction and presents results of stability analysis on starting a 20,000 hp motor in an electrical system with plant generation.