Gen2/Motor Controller/Operation

From Unofficial Zero Manual
Jump to navigation Jump to search

The controller is a switching MOSFET power supply that creates 3 phased sine wave outputs to drive the motor via Pulse-width modulation (PWM).

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”.
File:My2017sr-sevcon-scope.jpg
MY2017 Zero SR. Scope at Sevcon M3 Output Terminal