AC motors

[squashi]

Hello,

I am new to this forum and would like to post a question about industrial AC motors. I have been looking at the ABB range of motors & motor controllers recently to get some insight.

I'm designing a motorised railed tolley system for a greyhound racing stadium to drive the rabbit ahead of the dogs.

What are the advantages of using a low voltage (400V) AC motor system over an industrial DC motor? The operating speed of an AC inductance motor is based on the AC frequency and the number of poles, so how does the motor controller vary the running speed?
More importantly what happens when the motor is started?

I hope that you might be able to shed soem light on general direction and tips..

Thanks
sq

Mechanical Engineer

http://www.fastcomponents.co.uk

 

[Tmoose]

MD Launches new website
Machine Design has compiled all of our articles, Basics of Design Engineering and supplier information for AC motors, DC motors, Stepper motors, Servo motors and Gearmotors into a single site. The Electric Motors Reference Center can be found at

http://www.electricmotors.machinedesign.com

Electric Motors Reference Center

http://www.electricmotors.machinedesign.com/

> What are the advantages of using a low voltage (400V) AC > motor system over an industrial DC motor?
$$$$$$$$$ - A surprisingly sophisticated 3 HP VFD can be bought for less than $200

> The operating speed of an AC inductance motor is based
> on the AC frequency and the number of poles, so how does
> the motor controller vary the running speed?
VFD = Variable Frequency Drive

 

[squashi]

thanks, checking out that site now.

sq

Mechanical Engineer

http://www.fastcomponents.co.uk

 

[sreid]

Induction motor vector drives contlrol the phase voltages and frequencies to seamlessly control the motor speed and torque. The drive uses electrical complexity to replace mechanical complexity (brushes and commutators).

Vector drives are more reliable and require less maintenance (probably zero). Also, DC motor drives are sunset technology that are invariably old designs that contimue to be sold and will have spares availability problems (in my humble opinion).