Power Amplifier output to 3 Phase Motor


by smitty1701
Tags: amplifier, motor, output, phase, power
smitty1701
smitty1701 is offline
#1
May19-11, 09:59 AM
P: 1
Hello Everyone,

I have a question about how power amplifiers output their power to 3 phase motors. Im using a copley xtl power amplifier to power a 3 phase motor, i want to use a relay to interrupt that motor current but im not sure how to size it. If the peak output of the amplifier is 40A does that mean each phase of the motor can get 40A or does that mean the total output over the three phases is 40A? Im trying to get away with attaching each phase of the motor to one contact on the relay so i can hopefully use a cheaper relay without degrading safety. The power amplifier uses PWM to send a sine wave to the 3 phase motor.

Thanks for any help
Phys.Org News Partner Engineering news on Phys.org
PsiKick's batteryless sensors poised for coming 'Internet of things'
Researcher launches successful tech start-up to help the blind
Researchers propose network-based evaluation tool to assess relief operations feasibility
dlgoff
dlgoff is offline
#2
May19-11, 01:07 PM
Sci Advisor
PF Gold
dlgoff's Avatar
P: 2,631
Normally, you would use a starter circuit like this:



But if you have a Variable-frequency drive, just a 3 phase breaker (before the VFD) to break the supply is all that's needed.

As far as the rating goes, do you have the specifications of the VFD you're using?

Welcome to PF


Register to reply

Related Discussions
A question about DC motor (input power, output power) General Physics 3
Electrical Machines and Power Electronics - 3 phase, 6 pole induction motor Engineering, Comp Sci, & Technology Homework 1
amplifier's output Electrical Engineering 4
Calculating synchronous motor output power Electrical Engineering 0
Single-phase motor; Power factor Engineering, Comp Sci, & Technology Homework 1