(1) Inject a high-frequency voltage (sine wave voltage, 600hz to 2000hz) on d/q axis
(2) AD sample the motor phase current
(3) Use bandwidth filter to get the high-frequency response current signal
(4) Get the estimated q axis current (calculate by estimated rotor position). Actually, if the estimated position is the same with real position, the q axis current will converge to zero. So current error can be designed as a PI to output speed error in step 5
(5) By integer speed error, the rotor electrical position can be calculated. (the calculate rotor position was feedback to step 3). If the estimated position is the same with motor real rotor position, speed error is zero.
During HFI modulation period, motor phase current will responsible according to its estimated position. Below picture is a test current wave when HFI running.
(1) Inject a high-frequency voltage (sine wave voltage, 600hz to 2000hz) on d/q axis
(2) AD sample the motor phase current
(3) Use bandwidth filter to get the high-frequency response current signal
(4) Get the estimated q axis current (calculate by estimated rotor position). Actually, if the estimated position is the same with real position, the q axis current will converge to zero. So current error can be designed as a PI to output speed error in step 5
(5) By integer speed error, the rotor electrical position can be calculated. (the calculate rotor position was feedback to step 3). If the estimated position is the same with motor real rotor position, speed error is zero.
During HFI modulation period, motor phase current will responsible according to its estimated position. Below picture is a test current wave when HFI running.
When high frequency voltage inject in motor, current will reponsible according the estimated angle. So check the d/q current (filtered by BPF) and make below math equation convergence to 0 :
in up equation, Iqc will be 0 when estimated angle is correct.
