From Unofficial Zero Manual
- The switching attempts to produce a smooth sine wave to each output terminal via Space vector modulation strategy of PWM.
- The motor has 3 stator (casing-embedded) windings at 120° equally spaced offsets around the circumference.
- Each winding pulls from one motor terminal's output from the controller.
- Each winding electromagnetically pulls on the rotor.
- The forces need to balance out, not leading to a net lateral force on the rotor and shaft.
- It also shouldn’t precess or wobble or slip.
- The process of making the sine waves is “encoding”.