Part Number: DRV8312-C2-KIT
Hello !
We seem to be having an issue with sensored BLDC control of a motor that is connected as follows (according to pdf guide) to the DRV8312-C2-Kit.
It seems that the PWM that the DSP outputs to the BLDC driver is off by 60 degrees (one sixth of a cycle).
When the motor is rotated via means of another motor and the maximum Line BEMF is observed for each state of hall sensors it results in the following correct switching table.
|
Correct Conduction Between Phases |
Hall Sensor |
||
|
blue |
green |
white |
|
|
Black -> Red |
0 |
0 |
1 |
|
Black->Yellow |
0 |
1 |
1 |
|
Red->Yellow |
0 |
1 |
0 |
|
Red->Black |
1 |
1 |
0 |
|
Yellow->Black |
1 |
0 |
0 |
|
Yellow->Red |
1 |
0 |
1 |
Table 1
When the motor is rotated via development board with sensored bldc control it results in the following switching table, which is shifted by 60 degrees or by a single hall sensor state from the correct table.
|
Actual Conduction Between Phases |
Hall Sensor |
||
|
blue |
green |
white |
|
|
Black -> Red |
1 |
0 |
1 |
|
Black->Yellow |
0 |
0 |
1 |
|
Red->Yellow |
0 |
1 |
1 |
|
Red->Black |
0 |
1 |
0 |
|
Yellow->Black |
1 |
1 |
0 |
|
Yellow->Red |
1 |
0 |
0 |
Table 2
When the motor is rotated via development in sensorless bldc mode and hall sensors are observed, they are in accordance to Table 1, further confirming that it is the correct switching sequence.
This can be further observed via phase current waveforms In sensored bldc mode (Fig. 1) which are incorrect when compared to the correct waveform observed in sensorless bldc operation (Fig. 2).
Fig. 1 – Sensored BLDC Control phase current waveforms (incorrect).
Fig. 2 – Sensorless BLDC Control phase current waveform (correct).
It seems like this is a code issue and if possible we would like to receive a program file that allows for correct operation that we can flash to the controller.
Best Regards,
