Baldor mn722 manual Section Manual Tuning the Series 22H Control

Section 6

Manual Tuning the Series 22H Control

Manually Tuning the Control In some applications the drive cannot be accurately auto-tuned in an application. In these cases it is necessary to calculate the values needed to tune the drive and manually enter these calculated parameter values.

Motor Mag Amps Parameter This parameter is located in the Level 2, Motor Data Block. This parameter is normally entered using the nameplate data (motor no load amps) or auto–tuned. If no other data is available, set Motor Mag Amps parameter to about 40% of the motor rated current stated on the nameplate.

The following procedure should be used for setting the Motor Mag Amps parameter with the motor coupled to the load:

1. Adjust the Motor Mag Amps Parameter to 40% of the motor nameplate full load current rating.

2.Give the controller a speed command input of 80% of the Base Speed on motor nameplate.

3.Select motor voltage on keypad display by pressing the DISP key until the motor voltage value is displayed.

4.Observe the motor voltage. Ideally, it should read 80% of motor nameplate voltage. By raising the Motor Mag Amps parameter value, the motor voltage will raise proportionally. Continuing to raise the Motor Mag Amps parameter value will eventually saturate the motor voltage. By lowering the Motor Mag Amps parameter value, the motor voltage will lower proportionally.

5.While the motor is running adjust the Motor Mag Amps parameter until the display indicates the proper voltage (80% of motor rated).

Slip Frequency Parameter This parameter is located in the Level 1, Vector Control Block. The slip frequency

may be calculated from nameplate data or auto tuned.
Fslip	+ Rated Freq * ￿		(Rated RPM x Number of Motor Poles)		￿ OR
		120
Fslip	+ Rated Freq * ￿		Base Speed	￿(Rated Freq)
			Sync Speed

Current Prop Gain Parameter This parameter is located in the Level 1, Vector Control Block. The Current Prop Gain parameter is normally auto–tuned when motor inductance is not known. Where auto–tuning can’t be used, the proper manual setting for the proportional gain can be calculated by:

￿740 x L x ￿A￿V￿￿

Current PROP Gain +

Where:

VAC

L = Line to neutral leakage inductance of the motor in mH

VAC = Nominal line Volts

A/V = The Amps/Volt scaling of the current feedback

Motor line to neutral leakage inductance can be obtained either from the motor manufacturer or by measuring the line–to–line inductance and dividing by two.

The A/V scaling for the controller can be found in the diagnostic information located in the

DISPLAY MODE.

For most applications setting the Current Prop Gain parameter to a value of 20 will yield adequate performance.

MN722 Manual Tuning the Series 22H Control 6-1