The Tesla Roadster is powered by this motor. What is the meaning of i?
You need to specify what type of motor you have. There are two basic types: DC - is it a shunt motor or a series wound motor? a resistor can be used for speed control of both of these but the characteristics are different for each. AC - is it single or 3 phase? the only type of ac induction motor that can use a resistor for speed control is a wound rotor type. For standard induction motors you need an electronic device that varies the frequency, but bear in mind that the power output will be less at lower speeds for the same supply voltage.
This Site Might Help You. RE: What does it mean by 3 phase, 4-pole electric motor? The Tesla Roadster is powered by this motor. What is the meaning of i?
They left out an important part. It's an AC induction motor. Here www.physclips.unsw.edu.au/jw/elec... The motor is a VERY simple deal - a cage of metal, which spins. It spins inside fixed magnetic coils (3 sets repeated 4 times). This makes a magnetic field inside the motor, which spins. Through the magic of induction, it tends to drag along the cage with it. That's what makes the car go. The voltage and frequency you send to the motor, controls the power and speed that the shaft wants to turn. An induction motor wants to rotate slightly slower than the magnetic field is spinning. For instance on a shop-tool motor, the field spins at 1800 RPM, and so the motor tends to spin at about 1725, give or take. Kinda like an electric version of a torque converter. A lot like one, in fact! On a torque converter, if the road is going faster than the engine, the road will push the engine - thus engine braking. On an induction motor, if the frequency/ RPM of the magnetic field is faster than the rotor, it will generate electricity! Thus regenerative braking. Modern power electronics make this all work like magic. They allow any frequency of 3-phase AC to be created. So the motor is easily controlled. The power electronics are quite sophisticated, but they have no moving parts (except a cooling fan) and thus never wear out. The motor is very simple too... a perfect combination.
