ac drive

Hello Dhiru, Generally speaking.... In scalar control, a VFD commands a motor to run a certain speed by modulating the output frequency and RMS voltage. Unfortunately the VFD has no idea if the motor is responding correctly to that command, it just keeps humming along blissfully ignorant even if the load causes the motor to slow down or the line voltage drops. Vector control is all about adjusting for changes in the load and system. A vector drive uses feedback from what is happening at the motor (measuring) to make changes in the output of the drive in order to affect the desired outcome with the motor, i.e. speed or torque accuracy. Good luck

Hi..chatepilar..

i would like to clarify u mean that scalar is w/o feedback and vector control is with feedback loop right? Also what devices must i install inorder to detect the changes in load driven by a variable speed dive motor? Can a motor controller do that? ie. like a SEW motor controller.. many thanks..

If the drive is driving a pump a pressure transducer can give feedback...if it is a fan then wind speed can be used to give feedback..

I have not used Sew..better ask the supplier on that...

Good luck