System and method for estimating the position of a wound rotor synchronous machine

A computer-implemented method for determining a rotational position of a rotor within a synchronous machine, the method comprising:

• applying three-phase voltage to a plurality of stators of the synchronous machine;
• determining the voltage applied to each of the plurality of stators and a field voltage induced across windings of the rotor;
• determining phase shifts between the field voltage and each of the applied voltages;
• and
• comparing the phase shifts to a lookup table or closed form expression including a relationship between phase shifts and rotor position to determine the rotational position of the rotor.

A vehicle, comprising:

• a plurality of axles;
• a plurality of wheels, each wheel coupled to one of the plurality of axles;
• at least one motor rotatably coupled to one of the plurality of axles and including at least one stator winding pair configured to create a magnetic field when an input voltage is applied and a rotor having a field winding and being configured to rotate within the magnetic field created by the at least one stator winding pair;
• a phase detector configured to determine a phase difference between the input voltage and a field voltage induced in the field winding of the rotor;
• and
• a processor configured to receive a signal from the phase detector indicative of the phase difference between the input voltage and the field voltage and to estimate the rotor position based on the phase difference.