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Magtrol Model DSP7000 Dynamometer Controller
Appendix A: Inertia Correction
APPENDICES
a.2.1
k
ey
C
onDiTionS
•
Select appropriate value
. The test point selection of 78% is typical for an induction motor.
Use a value in the linear portion of the motor curve where there is a substantial torque change
with speed.
•
acquire data rapidly
. Rapid data acquisition is necessary so that motor heating does not
degrade performance by adding a false difference between the static and dynamic torque
values.
•
Use a regulated power source
. The input line voltage must be stable for the time necessary
to perform the test. Torque varies by the square of the change in line voltage.
•
Obtain new CF value for various deceleration/ acceleration rates
. The CF is only valid
for its specific ramp rate. To calculate other CF rates, use the following equation:
CF
new
= (CF
old
/ramp rate) × new ramp rate