6 Replies Latest reply on Nov 22, 2018 5:04 PM by einarh_01

# Error reconstruction (AN204470 HFI low speed)

Hello, friends! Where is the error reconstruction flow chart (AN204470 HFI low speed)?

• ###### 1. Re: Error reconstruction (AN204470 HFI low speed)

(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.

• ###### 2. Re: Error reconstruction (AN204470 HFI low speed)

Where id-bpf-sin-lpf signal is used?

In the “ Error Reconstruction” block there are two inputs (Id * sin, Iq * sin)

• ###### 3. Re: Error reconstruction (AN204470 HFI low speed)

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.

• ###### 4. Re: Error reconstruction (AN204470 HFI low speed)

what is inside the "error reconstruction" block (two inputs - Id * sin, Iq * sin) ... draw a diagram, please

• ###### 5. Re: Error reconstruction (AN204470 HFI low speed)

what is inside the "error reconstruction" block (two inputs - Id * sin, Iq * sin) ... draw a diagram, please