Guest Posted May 28, 2005 Report Share Posted May 28, 2005 How to speed control of 3-phase induction motor Link to comment Share on other sites More sharing options...
marke Posted May 28, 2005 Report Share Posted May 28, 2005 To control the speed of a three phase induction motor, you must vary the frequency and voltage of thw upply applied to it. If you halve the frequency, the motor will run at half speed. If you reduce the frequency, you must also reduce the voltage such that the ratio of v/f is kept constant.There are inverters available from most electrical manufacturers that are designed for the speed control of induction motors.Have a look at http://www.motor-control.co.nz for some examples. There are some special motors with a very high resistance rotor that can be reduced in speed by a reduction in the applied voltage. Thes are a high slip motor with a high resistance rorot and sometimes are used as the integral moto on a fan unit. Do not try tovary the speed of a standard induction motor by voltage control as the motor will be damaged. Best regards, Mark Empson | administratorSkype Contact = markempson | phone +64 274 363 067LMPForum | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now