Sensorless BLDC motor , High current @ start up

Amit Patil

Intellectual 900 points

Other Parts Discussed in Thread: CONTROLSUITE

Hi,

Can any one help me for BLDC motor control Algorithm.

after installation of controlSUITE. I got modules for sensorless BLDC control Algorithm

C:\TI\controlSUITE\libs\app_libs\motor_control\math_blocks\fixed



C:\TI\controlSUITE\libs\app_libs\motor_control\drivers\f2803x

by using this module. i have succufully commutate the sensorless BLDC motor

and used in my application. it ran good. i have rn BLDC sensolress motor with 3600 RPM

but i have facing problem at start of the motor.

1) RC3_MACRO module

2) IMPULSE_MACRO module

above module used for start up commutation of sensorless BLDC motor. when i started motor was taking 10A to 20A

phase current.when it reaches at ramp level i switched in to Actual phase voltage feedback & close the system.

after that it tooks 1A current which is correct as per my load.

so i didin't understand why BLDC motor tooks high current @ start up?

over 9 years ago

0 Ramesh Ramamoorthy over 9 years ago

TI__Mastermind 27240 points

There is a variable called 'DfuncTesting'. Try to reduce that or fiddle with that value. Hopefully it should fix.

0 Amit Patil over 9 years ago in reply to Ramesh Ramamoorthy

Intellectual 900 points

Hi Ramesh,
Thanks for valuable response . I tried with different values of DfuncTesting , if I m not wrong then DfuncTesting is used for control PWM ON time, now used 6%(DfuncTesting = 2000) PWM on time .
It improved, but still it takes 9A current @ open loop. When I reduces more than 6% BLDC motor is not rotating.
Can you have another solution for that. Waiting for your valuable solutions.

Regards

Bipin

0 Ramesh Ramamoorthy over 9 years ago in reply to Amit Patil

TI__Mastermind 27240 points

There are two things that control the motor, one is the duty cycle and the other is commutation timing. Since the people that developed it are not around to support further inner details, I recommend you to review the code and get more insight so that you can debug it more effectively. You could also review the docs folder for more information.

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Sensorless BLDC motor , High current @ start up