vibrating feeder with VFD

Dear,

i was reading about vibrating feeders with VFD's with embedded controller. I understood that VFD will be needed to make constant speed rate at various load conditions and will make the feeder start softly (soft start). how this is done? is control done automatically?

Thank you for your feedback,

charbel

Normally you have a flow rate setpoint. You will control the speed of the vfd to try and get to that setpoint (normally with a plc or some stand-alone controller)

Thank you dear,

Do I need to connect the standalone controller to a field instrument (for measuring speed or anything else) or is this done automatically by the standalone controller based on flowrate setpoint.

For higher accuracy you can get the speed feedback but most of the cases ive done vibrating feeders this wasnt neccesary. You will use the flow rate (scales,weight) as your process variable and just send a speed output to the drive according to the flow rate.
If your vfd has the option of pid controller built in you wont need a standalone controller or plc

Thank you Chud