SINAMICS S120 Functi.. - Gregbotos.com

Operating ModesVector control3.2.12 Efficiency optimizationDescriptionThe following can be achieved when optimizing the efficiency using p1580: Lower motor losses in the partial load range Noise in the motor is minimizedsetp15800 %p157050 %p1570*0.75100 %p1570*0.5p1570*r0331/2p1570*r0331iqset (r0077)Fig. 3-42Efficiency optimizationIt only makes sense to activate this function if the dynamic response requirementsof the speed controller are low (e.g. pump and fan applications).For p1580 = 100 %, the flux in the motor under no-load operating conditions is reducedto half of the setpoint (reference flux) (p1570/2). As soon as load is connectedto the drive, the setpoint (reference) flux linearly increases with the load and atapprox. r0077 = r0331 * p1570 reaches the setpoint set in p1570.In the field-weakening mode, the final value is reduced by the actual degree of fieldweakening. The smoothing time (p1582) should be set to approx. 100 to 200 ms.The flux differentiation (also refer to p1401.1) is automatically de-activated internallyafter magnetization.Overview of important parameters (refer to the List Manual) r0077 CO: Current setpoints, torque-generating r0331 Motor magnetizing current/short-circuit current (actual) p1570 CO: Flux setpoint p1580 Efficiency is optimizationFunction diagrams (refer to the List Manual) 6722 Field weakening characteristic, Id setpoint (ASM, p0300 = 1) 6723 Field weakening control, flux control for induction motors(p0300 = 1)3-154© Siemens AG 2006 All Rights ReservedSINAMICS S120 Function Manual, 03/2006 Edition