Dynamical simulation of electrical machines using numerical modelling
Electrical machines behavior analysis on dynamic situations by simulation. Such situations are eg. direct on-line start, flying start, 2- and 3-phase short circuit, opposite synchronization, loss of synchronism. Needed input for the analysis is usually equivalent circuit parameters, or time constants/reactances, which are normally available from machine manufacturer. Outcome of analysis is all machine variables, torque, currents, voltages as function of time, which can be provided in graphs and in numeric format included in comprehensive report. ย Analysis can be used eg. for, trouble shooting / root cause analysis of failure, setting mechanical structure design / engineering criterias for fault torques, setting electrical engineering criterias for fault currents, obtaining machine fault torques for torsional analysis of drive train, etc.
Case example: 75.3 MVA Hydro generator โ Electrical stress (voltage and current) to the excitation supply system was surveyed using simulation. Rotor current, rotor voltage and torque were solved, as a function of time, on cases of: 3- & 2-phase short circuits, improper synchronization at phase opposition and loss of synchronism.