Rotary-field motor control using integrated current difference - depends on actual stator current and desired current value which does not exceed predeterminable stator current set-point

摘要

An induction motor (15) is supplied from an invertor (11) controlled by a modulator (10) for which a modulation control signal (f1) for setting the stator supply frequency is obtd. by time integration (5) of the current difference signal dependent on a given limited desired value of current, falling with the ratio of stator voltage to frequency. For traction and braking the stator frequency signal is dependent on a desired rotor frequency and a mechanically detected actual frequency (fm). Stator voltage may be regulated by the stator frequency and an intermediate-circuit DC voltage (Usk). USE/ADVANTAGE - With railway locomotive and railcar traction motors, very rapid changes in speed are prevented and for wheelslip protection a relatively slow computer (e.g. 10 ms cycle time) is sufficient.