Cannot enter closed loop mode（sensorless）

[七七曹]

Software：MTRCKTSPNZVM128_SW_2018_5_25（Dualshunt）；

Supply current is 0.28A，but freemaster shows 1A；

What special settings do the hardware jumper caps require?

[pachamatej]

Hello,

first of all:

• Hardware scales are related to the HW setup, it is not a subject of the SW, however, the SW should "know" what is the analog value scale. Your settings indicate that the HW shunt resistor or the gain has changed. Originally, the HW scale is Imax = 20 Amps. If you haven't changed the shunt resistor or the op-amp gain, you can see a different current than the real one is, in this case 20/6 x more (your 1 Amp is 3.33 Amps real phase current). If you are using the EVB with no change to the HW, please use Imax = 20 Amps. Picture number 7 shows the failure caused by the wrong current scale - your speed PI controller limit is 5 Amps, however due to the current scale mistake, the actual limit is 16.7 Amps, which may cause a high current flow from the DC-link and the power source, which probably caused the Udcb Lo (undervoltage) situation when the power source overcurrent protection reacted.
• Power converters act as a transformers - if we neglect the efficiency, the input power equals the output power, while the voltages and currents are changed, thus Uin * Iin = Uout * Iout. Since the input voltage is e.g. 12 Volts and the output voltage may be e.g. 1.2 Volt, the input current would be 1 Amp even if the output current is 10 Amps. Please consider this as an easy-to-understand example. In 3-phase converters, the output and input currents are more complicated since the phase and line-to-line voltages and currents are different from the DC-link.
• Speed loop tab: I'm not sure if the speed ramp set to 20 RPM/sec is correct. That would mean that the acceleration from 1000 to 5000 RPM would take 200 seconds (more than 3 minutes)
• Sensorless tab: Merging speed 1 must be lower than the Merging speed 2. In your settings, the values are not correctly aligned.

I believe the jumpers are set correctly.

Best regards,

Matej