Re: Acceleration Time
Dear Mr Prakash,
Rewriting your formula:
Torque = Im * d(omega)/d(time)
into
d(time) = d(omega) * Im / torque
in which
Torque = momentary driving torque – momentary load torque
The driving torque is a function of the momentary omega (rpm).
f.i. a squirrel cage motor has a certain torque= function(rpm) curve.
The load torque is a function of the momentary omega (rpm).
f.i. a fan creates a higher counter torque at a higher rpm.
Im = moment of inertia, reduced at driving shaft
Torques are also taken at drive shaft.
By dividing the drive- and load curves in rpm increments and determining the drive- and load torques at the middle of those increments, the increments of the used acceleration time can be calculated.
By repeating this calculation until the desired rpm is reached ( or the accelletation torque becomes =< 0), the acceleration time is the sum of the time increments.
(numerical integration)
See the attached spreadsheet calculation.
Success
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Teus
Acceleration time
Dear all,
I have more projects related with power calculations of system.
All rotating mechanical elements with power supply of centralised main motor.Frequently i am using the formula T=I*Alpha where Alpha is Angular acclearation i.e omega/time Here while giving time I have more confusion.Say motor rotates 1440 rpm at what time it will accelerate to the required rpm? In motor catalogues there is no details?Also lot of subsystems are running by using of main motor. All sub systems are not identical also there is no time relative functions involved.(Mostly induction motor types)
Any ideas,or reference materials welcome
Thanks advance
Prakash ■