Patent ID: 8583265

Claim:
A method, comprising: iteratively executing a slow-rate task processing loop that executes at a relatively slow-rate during a first task processing period (T TASK2 ); iteratively executing an intermediate-rate task processing loop that executes at an intermediate-rate during a second task processing period (T TASK1 ), wherein the step of iteratively executing the intermediate-rate task processing loop, comprises: computing, at the intermediate-rate (T TASK1 ), a new instantaneous switching frequency (f SW — new ); and computing tri-state values for a PWM voltage advance delay time, wherein the tri-state values for the PWM voltage advance delay time comprise: an initial steady-state value for the PWM voltage advance delay time (t PWM — Adv — inital — ss ); an intermediate value for the PWM voltage advance delay time (t PWM — Adv — intermediate ); and a final steady-state value for the PWM voltage advance delay time (t PWM — Adv — final — ss ); iteratively executing a fast-rate task processing loop that executes at a relatively fast-rate during a third task processing period (T Task0 ), wherein iteratively executing the fast-rate task processing loop comprises: computing tri-state values for a PWM voltage advance angle (Δθ) that are used during a transition state when a current actual switching frequency (f SW ) changes to the new instantaneous switching frequency (f SW — new ), wherein the tri-state values for the PWM voltage advance angle (Δθ) are computed based on: a product of the initial steady-state value for the PWM voltage advance delay time (t PWM — Adv — inital — ss ) and an angular rotor velocity (ω r ); a product of the intermediate value for the PWM voltage advance delay time (t PWM — Adv — intermediate ) delay time and the angular rotor velocity (ω r ); and a product of the final steady-state value for the PWM voltage advance delay time (t PWM — Adv — final — ss ) delay time and the angular rotor velocity (ω r ).