SINAMICS S120 Functi.. - Gregbotos.com

Operating ModesServo controlFormula to calculate the cable resistance:R (cable resistance) copper = 0.0178 I = Cable length [m]A = Cable cross-section [mm 2 ] (specific resistance) l (cable length)A (cross section)The motor should be at room temperature when the identification routine is carriedout.The compensation of the voltage emulation error must be activated (p1780.8= 1).A KTY sensor (p0601 = 2 or 3) should be used to sense the motor temperature(p0600).The estimator requires the motor temperature in order to track/correct the temperature-dependentquantities. If a motor temperature sensor is not connected, thenthe accuracy is significantly restricted.The k T estimator is only activated above a specific speed (p1752). The terminalvoltage of the drive converter always has small errors, caused by voltage drivesacross the power semiconductors etc. The lower the speed and therefore the outputvoltage, the greater the negative influence on the estimation as a result of lowvoltage errors. This is the reason that the estimation is de-activated below a specificspeed. The estimated value is smoothed using time constant p1795. The correctionvalue for the torque constant is displayed in r1797. By identifying the torqueconstant k T using the rotating motor identification routine, the torque accuracy canbe improved also below the speed threshold (1752).The k T estimator is activated using p1780.3 and the voltage compensation usingp1780.8.© Siemens AG 2006 All Rights ReservedSINAMICS S120 Function Manual, 03/2006 Edition3-81