Open-loop control of transient operation of rotating electrical machine

The invention provides open-loop control of transient operation of a rotating electrical machine. A method for controlling transient operation of a variable flux motor (VFM) includes receiving a commanded shunt angle and measuring a shunt angle when operating in a predetermined operating region (e.g., maximum torque per ampere or flux weakening) during a shunt angle transition. The method comprises calculating d-axis and q-axis incremental current terms ([Delta] Id and [Delta] Iq) required to maintain an output torque level of the VFM for the duration of the shunt angle transition, and then applying the required [Delta] Id and [Delta] Id terms as feed-forward terms to adjust the d-axis current (Id) terms and the q-axis current (Iq) terms according to respective lookup tables. In this manner, the controller maintains the output torque level of the VFM during the shunt angle transition. An electric powertrain includes the VFM, a TPIM, and the controller. The PM motor may be controlled by replacing the shunt ang