PowerSwitch

A British company which has developed pioneering electric car motors that do not rely on expensive rare magnets is preparing to raise £250m as it seeks to expand....
https://advancedelectricmachines.com/te ... ssrelease/

Already fitted to the Tesla Model 3

https://cleantechnica.com/2018/03/11/te ... -in-depth/

Works well. Very efficient

I suspect that if successful it will follow the well worn path of British industry such as ARM company of being subject to an unopposed foreign takeover then production moved to China.

I have heard of switched reluctance technology but never worked on it myself. From what I understand it is form of synchronous electric motor rather than the typical induction motor that is asynchronous and is probably more efficient and easier to control the speed of the motor. For the non techies I will leave it at that for now.

I have seen switched reluctance motors in industrial use. They are more efficient than standard induction motors, but only by a small margin.
A saving of 2% to 3% was claimed by use of a switched reluctance motor in place of a standard induction motor.
On a 20 KW motor, this is about 500 watts. For a long hour load, 500 watts is about 4000 KWH saved in a year. This will save from £400 to about £600 a year.

The slightly reduced loading will also reduce the losses in transformers and cables, perhaps by another £25 a year.

This probably explains why the Tesla model 3 is the most energy efficient mass market EV

I recall some being used for a large variable speed fan of some sort on a gas turbine project I was working on. The motor drives controlling these switched reluctance motors were very 'reluctant' to work properly during commissioning. This work was done by others so I am not sure what the issues were.

There are some excellent videos on YouTube that explain how these actually work. I was aware that Tesla were using them which is rather ironic since Mr Nikola Tesla actually invented (or maybe much improved) the three phase induction motor himself.