3 ms·
Three phase power is extraordinarily useful for electric motors. Mount three electromagnets radially and wire each up to a different phase, and you get a rotati
by ThrustVectoring 9y ago
Three phase power is extraordinarily useful for electric motors. Mount three electromagnets radially and wire each up to a different phase, and you get a rotating magnetic field that spins on the axis. Electric generators produce three-phase power pretty naturally through the inverse process of spinning a magnet through the resistance provided by three groups of windings.
- blattimwind 9y agoYou can have a two phase power system[1], but two phase generators are less efficient and more expensive relative to three phase – for the exact same reason why power distribution is less efficient and more expensive relative to three phase. [1] two phases in quadrature, which is very different from split phase, which is not two phase at all.
- ThrustVectoring 9y agoIIRC these designs don't naturally have torque at zero speed like three-phase induction motors do.
- Animats 9y agoYes. One of Tesla's more useful inventions was figuring out an simple way to get a synchronous motor started. Pre-Tesla schemes involved auxiliary starting motors and clutches. Tesla figured out how to run a synchronous motor in induction motor mode during starting.
- Pyxl101 9y agoTo clarify, do you mean Tesla the person or Tesla the car company? I figure the answer should probably be obvious to me, but I'm not an electronics person and it's not.
- ThrustVectoring 9y agoNikola Tesla, the late 19th / early 20th century inventor. Induction motors have been around for over a century.
- epx 9y agoTwo-phase 90 degrees apart has zero-rpm torque, like a steam locomotive, the problem is that torque is variable. Three phase torque is constant.