Rockwell Automation Publication 750-AT006D-EN-P - January 2022
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Chapter 4 Auto Tuning
Current regulator gain calculations prior to firmware release 10.00 are given below:
10:444 [VCL CReg C/U Select] allows either calculated or user-entered parameters to be applied to current loop gains. It also allows you to
transfer calculated parameter values to user-entered parameter values so you can use them as a starting point for manual tuning if desired.
The following parameters are applied as current loop gains when 10:444 [VCL CReg C/U Select] = Calculated.
10:446 [c VCL CReg Kp]
10:448 [c VCL CReg Ki]
These parameters are calculated based on 10:445 [VCL CReg BW], 10:511 [c IM Stator Res], and 10:514 [c IM Leakage L] when
10:510 [MtrParam C/U Sel] = Calculated (0) or they are based on 10:445 [VCL CReg BW], 10:512 [u IM Stator Res], and 10:515 [u IM Leakage L]
when 10:510 [MtrParam C/U Sel] = User Entered (1). The calculations are automatically updated when one or more motor-nameplate values
change.
The following parameters are applied to the controller when 10:444 [VCL CReg C/U Select] = User Entered.
10:447 [u VCL CReg Kp]
10:449 [u VCL CReg Ki]
This selection allows you to enter values for these parameters directly.
shows how the two selectors impact various parameters
and ultimately current loop regulator gains.
Figure 64 - Current Regulator C/U Selector
Modes
This section covers the Autotune modes that are used to measure motor electrical parameters.
10:910 [Autotune] = Static MtrID (2) – Enables the Autotune function to perform the Static Motor ID Test for induction motors only. After
selecting this value, you must issue a start command to begin the test.
Use this test when the motor cannot rotate freely or when it is already coupled to the load. The static test does not initiate momentary motor
rotation to measure motor electrical parameters. Instead, it only measures electrical parameters that do not generate motor movement. The
rest of the parameters are calculated from a lookup table. A resistance and inductance test updates the following parameters.
10:512 [u IM Stator Res]
10:515 [u IM Leakage L]
The following values are also calculated from a lookup table. However, they are measured more accurately during a rotate test.
10:490 [u Slip RPM atFLA]
10:518 [u Flux Cur Ref]
The following values remain their default values and are not updated during a static test.
10:521 [u EndLs AngCmp]
10:524 [IM StatResComp]
10:910 [Autotune] = Rotate MtrID (3) – Enables the Autotune function to perform the Rotating Motor ID Test. After selecting this value, you
must issue a start command to begin the test.
Automatic
Calculations
VCL CReg BW
445
446
448
444
VCL CReg C/U Sel
Calc
User
447
449
511
Calc
User
510
514
From
Automatic
Calculations
MtrParam C/U Sel
To Current
Regulator
c IM Stator Res
c IM LeakageL
512
515
u IM Stator Res
u IM LeakageL
c VCL CReg Kp
c VCL CReg Ki
u VCL CReg Kp
u VCL CReg Ki
000
= Read Only
000
= User Entered
From
Autotune
Results
Automatic
Calculations
VCL CReg BW
445
446
448
444
VCL CReg C/U Sel
Calc
User
447
449
511
Calc
User
510
514
From
Automatic
Calculations
MtrParam C/U Sel
To Current
Regulator
c IM Stator Res
c IM LeakageL
512
515
u IM Stator Res
u IM LeakageL
c VCL CReg Kp
c VCL CReg Ki
u VCL CReg Kp
u VCL CReg Ki
000
= Read Only
000
= User Entered
From
Autotune
Results