Other Parts Discussed in Thread: CONTROLSUITE
I am trying to control a 3 pole pair , 3000 rpm motor with inbuilt resolver. I am able to run the motor smmothly at speed as low as 60 rpm at build level 5 with fine tunning of current and speed loops. I am converting resolver signal to incremental and made sure that the index pulse is coming at the same location in each mechanical revolution.TI has used a variable called calibrated angle to match the offset between phase a winding and rotor zero.still i am confused because for various values of calibrated angles, the motor is running. for some of the values, the motor runs vauge till it finds the index pulse, and after that it runs well. but this feature is troubling me for precise position control. if i am putting a certain value of calibrated angle, then i am able to do position control from specified location, but not from all locations. in this case motor oscillates at power on and gets heated. can anybody help me out to find correct offset for my motor? I need to have precise position control from any location.some documents suggest to monitor back emf zero crossing of phase a winding and index pulse of encoder and the difference will be offset angle. but it is hard to monitor on scope if i am turning the motor with hand.
if i use direct absolute angle coming from RDC, will it resolve the above mentioned problem, as absolute angle will be used for commutation.
secondly what should be done to run the motor for speeds like 10 rpm ? do i need to retune the loops or filtering of spped should be more effective?
