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Determining relay settings for motor protection using published and empirical data

Conference · · Proceedings of the American Power Conference; (USA)
OSTI ID:7085940
 [1];  [2]
  1. Virginia Power Co., Richmond, VA (USA)
  2. Westinghouse ABB Power T and D Co., Protective Relay Div., Allentown, PA (US)
This paper describes the relation between the thermal limit curves and the published parameters of an induction motor and how this data is used to determine relay settings for thermal and fault protection of stator and rotor. This is done using the high inertia drive example of a 6000 HP induced draft fan motor. The application example includes the input data, method, and results of a complete motor starting study which determines the temperature rise in the motor during starting. The study is carried out using a PC application program which was written to calculate and plot starting current, speed, torque and rotor temperature versus time. The plot provides the same information as an oscillograph of an actual starting condition. This data is then used to compare the application method and effectiveness of a conventional overcurrent relay scheme requiring underimpedance supervision with microprocessor based protection employing rotor and stator thermal models.
OSTI ID:
7085940
Report Number(s):
CONF-890425--
Conference Information:
Journal Name: Proceedings of the American Power Conference; (USA) Journal Volume: 51
Country of Publication:
United States
Language:
English