When driving a BLDC motor, the driver aligns the motor but as soon as it starts to ramp up, the motor jitters and the driver hits the over current lock and over temperature faults. The motor has a fairly low resistor value (0.315 ohms), but it is just a test and the motor we would like to drive for our application has an even lower one (0.1615 ohms, 14.15 microH). Are we getting some settings wrong, or is it possible that the motor is not compatible with the driver?
More context on our setup is given below.
We are trying to drive the motor using the DRV10983-Q1 with an ATMega128 as the master controller; in other words, we are not using the tuning software and are instead writing the configuration to the DRV over I2C from the ATMega. The supply voltage is 12V, 3A max. The changes we are making to the default are as follows:
- Rphase = 0.315 ohm
- Kt = 0.096 V/Hz
- Open Loop Current = 1.6 A
- Align Current = 1.2 A
- Poles = 6
- Over Temperature current limit = 2 A
I have written a script to calculate what the configuration registers 0x90 - 0x96 should be and have obtained:
Reg Default --> New
-----------------------
0x90: 0x1048 --> 0x1228
0x91: 0x2F3B --> 0x3D3B
0x92: 0x0050 --> 0x00D0
0x93: 0x1B8A --> 0x1B8A
0x94: 0x3FAF --> 0xFFAF
0x95: 0x3C43 --> 0x3C43
0x96: 0x016A --> 0x016A
I have tried adjusting the ramp up current limits and open-to-closed loop threshold, and the motor appears to spin while skipping but still hits the same faults.
I've attached an image of the ATMega128 output, showing the programming procedure, register configuration readback, and motor status reading for several align-ramp-lock cycles.
