Controlling the magnetization state of a variable flux machine

A control method for maintaining torque during magnetization state variation transition using a direct flux vector control module. Particularly, the method comprising: determining, by the DFVC module, a stator reference voltage in a dsqs frame from an estimated flux amplitude, a reference flux amplitude, a measured stator current, a stator reference current in the dsqs frame, and an estimated stator flux angle; driving the VFM with the determined stator reference voltage in a dsqs frame; deriving a stator current in the alpha-beta frame from measured 3-phase stator currents; determining, by a flux observer, the estimated flux amplitude, the estimated stator flux angle and an estimated magnetization state (MS) from the measured stator current in the alpha-beta frame, a stator reference voltage and the phase angle; and determining the reference flux amplitude from a reference torque and a reference magnetization state; wherein the magnetization state (MS) is adjusted such that the torque (T) is maintained.