Patent ID: 6720748
Filing Date: 2004-04-13
Classification: H02P

Abstract:
A method for use with an adjustable frequency controller to deliver current to an electromagnetic load including a stator and a rotor, the method for identifying a flux current estimate and comprising the steps of:(a) identifying a rated torque value; (b) providing an initial q-axis current estimate; (c) using the q-axis current estimate to identify a d-axis current estimate; (d) mathematically combining the d-axis current estimate and the q-axis current estimate to identify a torque estimate; (e) comparing the rated torque value to the torque estimate; (f) where the torque estimate is similar to the rated torque value skipping to step (i); (g) altering the q-axis current estimate; (h) repeating steps (c) through (f); and (i) storing the d-axis and q-axis current estimates as flux and torque current values for subsequent use.