Rotor position sensing for a wound field synchronous machine at or near standstill

摘要

A starter-generator arrangement for aeronautical applications includes a multiphase alternating current (AC) wound field synchronous machine (WFSM) (8) that has a stator (12) with a selected number of poles, an associated exciter (14) and a multiphase AC permanent magnet machine (PMM) (16) directly coupled to the WFSM. A method of sensing the position of the rotor (10) of the WFSM comprises the steps of: arranging for the stator (22) of the PMM to have a number of poles that is a sub-multiple of the selected number of WFSM stator poles; configuring the rotor (20) for the PMM to have high saliency; applying multiphase AC power of a selected frequency to the PMM stator; detecting at least one set of stator harmonic currents of the multiphase AC power resulting from the rotor saliency; converting the detected PMM harmonic stator currents from their multiphase coordinates to ab (alpha-beta) coordinates; rotating the converted PMM stator currents into a reference frame for at least one selected harmonic to generate ab coordinate harmonic current vectors; and estimating the position of the WFSM rotor based on the values of the ab coordinate harmonic current vectors in the selected harmonic reference frame.