Motors

There always seems some confusion about this so here is what I know about Tesla motors. Tesla currently uses two types of motors, Induction and Permanent Magnet.


In an induction motor, alternating current is run through windings in the stator (the stationary portion of the motor) to produce a rotating magnetic field. This magnetic field induces electric currents in the windings of the rotor (the spinning part of the motor) that generates an opposing magnetic field, causing the rotor to turn in the same direction as the magnetic field. The rotor of course spinning the wheels. More on that here.


The other motor is an alternative motor technology that Tesla calls a PMSRM, a permanent magnet synchronous reluctance motor. A synchronous reluctance motor has a series of electromagnets around the stator, but the rotor doesn't have any windings or permanent magnets. Instead, the rotor contains veins of a magnetic material interspersed with non-magnetic material, arranged so that it has a preferred orientation in the magnetic field created by the stator. To turn the rotor, the motor activates electromagnets in sequence, creating a rotating magnetic field that pulls the rotor along.


Here is an important thing to remember about power vs range. Induction motors provide high torque at low speeds but overall they are less energy efficient. PMSRMs are basically your high range energy efficient motors. Early on Model S And X used one or two induction motors…massive power but pretty poor range.


The Model 3 introduced a major redesign in the motors as the motors were also designed for the Semi (with 3 or 4 of them in a Semi). So, Tesla introduced the PMSRM battery in the rear on all model 3s with the induction motor in the front on LR and performance versions. This gives both single motor and dual motor model 3s a decent kick from the rear motor. The advantage the dual motor Teslas have is that they can send power to the induction motor when immediate, rapid acceleration is called for, then shift power to the PMSRM as the vehicle gets up to speed to conserve energy. The performance model basically has the same motors as the LR, but has a different silicon carbide inverter on the rear motor designed to dump more current into the PMSRM rear motor when needed, bumping the HP up.


HP ratings between the 3 basic model 3 models are 252 (RWD), 363(LR), and 460+(P). The LR can be bumped up to higher HP and 0.5 seconds shaved off the 0-60 via a software option purchase. 0-60 numbers in seconds are 5.5 (RWD), 4.4 (LR), 3.9 (LR w/software option), 3.1 (P), 3.0 (P- stealth option but basically just 18” tires on a P).


The new model S and X actually switch this around putting the PMSRM in front and the induction motor in back…with no loss of power or speed.