Vfd Or Ss

[jjj]

hi,

 

i want to control a motor using in amusement park.

 

the application requires ramp up time of 20 to 50 sec and ramp down of 20sec.

 

which i ve to use? (SS or VFD)

 

jjj

[botshe]

dear sir,

 

i would like to give some of notes depeding on your valuable requiest ,

 

i think that the choice between VFD and Soft starter depending on the application

so if you need to control with variable speed related to the change of voltage and frequency you can use VFD ,

therefor , if you need to control with variable speed related to the change of voltage only you can use Soft starter

 

 

i hope to provide with a good engineering knowlage

 

regards

 

botshe

[marke]

Hello JJJ

A VFD directly controls the speed of an induction motor by varying the frequency and voltage applied to that motor.

If you need a linear speed ramp, then use a VFD.

A soft starter controls the current drawn by an induction motor. The current then controls the torque where the shaft torque is equal to the full voltage shaft torque at that speed multiplied by the current reduction squared. If the load has inertia, then the rate of acceleration is a function of the inertia and the torque applied.

In many cases, the soft starter is perfectly adequate, but on a ride, I would expect that the linear ramp up and linear ramp down from a VFD may be more desirable.