JeffLowe Posted July 12, 2010 Share Posted July 12, 2010 The TComp tables being simply an additive compensation will do a reasonable job of compensating for cogging torque, however ripple needs a scale the control effort as a function of motor angle. This is probably best accomplished in a user written commutation routine as a prescaler to the sine/sine 120 phase distribution. Do any examples exist of user written commutation routines, especially ones geared toward ripple compensation? TIA Link to comment Share on other sites More sharing options...
curtwilson Posted July 13, 2010 Share Posted July 13, 2010 I'm not quite sure exactly what effect you are trying to compensate for, but I think your best first shot would be to build a "custom sine table". PMAC commutation uses a 2048-element sine lookup table in RAM, both for speed of calculation and possibility of modification. Saved setup variable Ixx55 lets you point to your own custom table instead of the built-in table. The brief instructions under Ixx55 in the Software Reference give enough information to tell you how to use such a table. Of course, you must decide how you want to customize the table. The values in the table are multiplied by your control effort value, so your "tweaks" here are scaled, unlike the TCOMP table values. Link to comment Share on other sites More sharing options...
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