Synchronous Motor Start-up Operation Modeling in Event of Load Bus Reactive Power Control

Synchronous motor rotor resistance (referred to stator) and full reactance (including rotor and stator) calculation procedure was developed. The input data to be used in the procedure was manufacturer data for cases when the current/slip, torque/slip characteristics are available (in reference books), and when they are unknown. The resistance and inductance values calculated with this procedure are used in the analysis of different cases when the synchronous motor is in asynchronous operation. Stator resistance was calculated based on the convention that it dissipates thirty percent of total losses. A particular example involving the synchronous motor and asynchronous motors of different rated power provided the calculation procedure error estimation. Approximate analytical resistance/slip and full reactance/slip characteristics were proposed and the estimation of the error that is substantially less than the alternative procedures error was provided. The developed calculation procedure is supposed to be used in the problems related to the reactive power control modeling in the event of synchronous motor start-ups.