Patent ID: 8076895

Claim:
A method for generating control signals (Sw 1 , Sw 2 , Sw 3 ) for a polyphase rotary electrical machine ( 2 ) comprising phase windings ( 4 ) each defining a phase of said electrical machine and rotor position sensors ( 1 ) for determining angular position of a rotor of said electrical machine such that a number of said sensors equals to the number of said phases, said control signals (Sw 1 , Sw 2 , Sw 3 ) controlling a power supply ( 10 ) to said windings ( 4 ), said method comprising the steps of: generating synchronization signals (Si 1 , Si 2 , Si 3 ) produced by said sensors ( 1 ); forming said control signals (Sw 1 , Sw 2 , Sw 3 ) by signals (So 1 , So 2 , So 3 ) shifted in phase by means of a processing unit ( 5 ) by a phase-difference angle (φ) continuously variable with respect to said synchronization signals (Si 1 , Si 2 , Si 3 ), said processing unit ( 5 ) comprising inputs ( 8 ) receiving said synchronization signals (Si 1 , Si 2 , Si 3 ) and outputs ( 6 , 7 ) transmitting said out-of-phase signals (So 1 , So 2 , So 3 ); said synchronization signals (Si 1 , Si 2 , Si 3 ) being binary signals having synchronization edges ( 11 - 17 ); generating rising and falling edges of said out-of-phase signals (So 1 , So 2 , So 3 ) after a level-switching delay (ΔT 1 ) being a function at least of said phase-difference angle (φ) from at least one reference edge chosen from said synchronization edges such that said delay (ΔT 1 ) being minimum.