SINAMICS S120 Functi.. - Gregbotos.com

Operating ModesVector controlfStartfZero crossoverClosed loopClosed loopp1755p1755Open loopOpen loopttp1755vektor_nulldurchgang.vsdFig. 3-27Start-up and passing through 0 Hz in closed-loop operationClosed-loop operation up to approx. 1 Hz (settable via parameter p1755) and theability to start or reverse at 0 Hz directly in closed-loop operation (settable via parameterp1750) result in the following benefits:No switchover required within closed-loop control (smooth operation, no dips infrequency).Steady-state speed-torque control up to approx. 1 Hz.NoteWhen the motor is started or reversed in closed-loop operation at 0 Hz, it isimportant to take into account that the system switches from closed-loop toopen-loop control automatically if the system remains in the 0 Hz range for toolong (> 2 s or > p1758).Function diagram overview (refer to the List Manual) 6730 Interface with Motor Module for induction motor (p0300 = 1) 6731 Interface to the Motor Module (PEM, p0300 = 2)3-124© Siemens AG 2006 All Rights ReservedSINAMICS S120 Function Manual, 03/2006 Edition