wonderwizard Posted June 30, 2015 Posted June 30, 2015 I would like to check my understanding of Ixx72 in relation to commutation of a brushless motor. I have a three phase brushless motor with 12 poles. Reading the SRM 683 or 1365 is typical for a three phase motor. ie 360/3 = 120degrees However I am unsure whether because I have a high pole count motor the phase angle is smaller, 60 degrees? 12 poles 6 pole pairs 360 / 6 = 60 degrees Cheers,
wonderwizard Posted June 30, 2015 Author Posted June 30, 2015 Steadily more confused.... http://www.deltatau.com/manuals/pdfs/TURBO%20SRM.PDF page 130 "A commutation cycle, or electrical cycle, consists of two poles (one pole pair) of a multiphase motor." So I have 6 pole pairs, electrical cycle = 360 / 6 = 60degrees I did have for my LV config: Ixx70 = 6 Ixx71 = 2097152 ; this is a full revolution in counts I now think I need: Ixx70 = 6 Ixx71 = (2097152 /360) * 60 The Geobrick LV manual seems to agree with this, page 170 http://www.deltatau.com/manuals/pdfs/GEO%20BRICK%20LV.pdf I would greatly appreciate anyone sanity checking that for me please.
steve.milici Posted June 30, 2015 Posted June 30, 2015 The commutation phase angle for the Geo Brick-LV is fixed at 683 for a three phase motor. Ixx70 should be set to the number of pole pairs and Ixx71 should be set to the number of counts in one full revolution of the motor (through all commutation cycles of the motor). So in your case: Ixx72=683 Ixx70 = 6 Ixx71 = 2097152
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