So I recently learned that Teslas use AC induction motors rather than DC motors. Now I always assumed that DC motors would be easier to control the speeds of vs. induction motors, so it surprised me that they used an induction motor in the Teslas. Now in my old days I had heard that induction motors are limited to the speed at which their input power frequencies run at. So to change their speed, you need to change their input power frequency. I heard that they use a variable frequency inverter system to achieve the different frequencies. Now from my understanding of inverters (limited), they produce a very square-wave AC pattern vs. a smooth sine wave AC pattern. The square wave is apparently not well liked by delicate electronics, but am I right in assuming that an electric motor wouldn't care if it's a square wave vs. a sine wave? If so, then the inverter probably doesn't have to be too sophisticated and need circuitry to convert the square into a sine wave? Also how do they vary the frequency of the inverter?