Simulating Soft Starter
Posted 09 February 2011 - 07:50 AM
I would like to know how should I decide on the ramp time and the amount of voltage applied (open-loop soft starter)
to simulate a simple soft starter using Matlab?
The motor I am using is a 150HP squirrel cage motor.
Posted 09 February 2011 - 06:00 PM
first, the initial start voltage must provide enough torque to overcome the load torque at zero speed by a margin to give you an acceleration torque.
Second the voltage profile must enable the voltage to vary at a rate that ensures that there is sufficient torque to accelerate the motor to full speed allowing for changes in load torque as the speed increases.
If you use a simple timed Voltage Ramp algorithm, then you need to ensure that the rate of rise of voltage is appropriate for the inertia of the load. If you have a short ramp with a high inertia load, you will be at full voltage before the motor reaches full speed and have a very high current. If you have a long ramp with a low inertia load, you will have a motor at full speed with low voltage and resultant high slip.
Mark Empson | administrator
Skype Contact = markempson | phone +64 274 363 067
LMPForum | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | Soft Starters
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users