The Switched Reluctance Motor ©2012 Dr. B. C. Paul Note – Concepts presented here in are considered common knowledge in the field and are found in numerous texts no one of which was intentionally copied. Figures are from various sources including “computer simulation technology”, Texas A+M University, Electric Motorbike Inc, Hearst Electric Products. List may not exhaustively site all locations where similar figures may be found.

The Switched Reluctance Motor The Stator contains 3 electro-magnets powered by DC Current.

The Rotor is a Plain Piece of Steel capable of carrying a magnetic flux The rotor is connected To a shaft that is it hoped will turn to make something happen.

The Path of Least Resistance Water will follow the path of least resistance Electricity will follow a path of least resistance

Magnetic Reluctance Magnetic flux likes to find an easy flow path A nice piece of steel is a much better flow path than air The magnetic flux will try to get the steel path to line up (considered magnetic reluctance)

Making the Motor Work If I keep turning magnetic fields off And on around the stator I can Have the rotor continuous chasing The magnetic field and thus Turning the shaft – I now have a DC motor with no Rings or brushes. (But one wholly Heck of a lot of switches)

Problems The torque the motor produces is proportional to where the rotor is relative to the poles The effect is highly non-linear As the rotor chases the poles the poles the torque ripples up and down

Try This A bunch of extra poles and then let a project logic controller program do the field Switching to smooth out the torque.

Of Course We have just created a motor that depends on a bunch of solid state switching technology and a computer to be able to operate That would have been a big deal in 1912, but not 2012. Its still a big deal if I’m talking ½ hp motors, but if I need a big torqueing motor a computer controlled motor is another story.