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2020-5-22
UG2020-11 REF-Vacuum-C101-2ED User Guide
10.
Double click “VF Diagnostic” function in motor1 page, monitor motor current with oscilloscope. If motor
current is not sinusoidal, change target speed and Vd_Ext in VF Diagnostic sub-function, then double-click
“VF Diagnostic” until oscilloscope shows a steady sinusoidal current, with amplitude of 30~50% motor rate
current.
Double-click “Iu & Iv_Slow” in System page > Monitor Definitions, the motor current feedback would be very
clean and sinusoidal, as shown in Figure 13, otherwise please tune “Gating Propagation Delay & Phase Shift
Window Size” in MCE Wizard. The sampled motor current amplitude should be over 300 cts ~500 cts
(corresponding to 30%~50% motor rate current); otherwise, motor current sample related hardware and
setup need tuning.
“VF Diagnostic”
sub function can verify:
•
If motor is correctly connected
•
If MOS & gate driver work as expected
•
If current sensing related parameters are correctly configured
•
If PCB layout and DC bus decouple have been done correctly
After “VF Diagnostic” is done, click STOP button (the red traffic light button) to stop PWM.
Figure 13
Trace waveform for Iu & Iv open loop diagnostic
11.
Start the motor by clicking the green traffic light button in the control bar (or double-click Start Motor sub
function in Motor1 page, group of User Application Function Definitions); motor runs if above step goes well.
12.
Check motor spin direction, adjust UVW connection order or set negative target speed in MCE Designer if
direction is wrong.
13.
Set target speed to about 50% of MAX speed, start “Iu & Flx_M” trace with “Auto Repeat On Level,” see
Figure 14. Flx_M is better within the range of 2000~2500 (rated value is 2048), and MUST be steady and DC-
like.
Some key tips for better motor-performance tuning:
•
If Flx_M is not steady (swinging or oscillating), double-check motor parameters, speed loop PI gain, flux Estimator
time constant and PLL PI bandwidth (parameters PLLKp & PLLKi) related setup.
•
If Flx_M is very noisy, double-check current feedback and Vdc-related hardware and parameters.
•
If Flx_M is far from 2048, “Motor Back EMF Constant (Ke)” needs to be adjusted in MCE Wizard.
