Using torque-ripple-induced vibration to determine the initial rotor position of a permanent magnet synchronous machine

In this letter, a method of determining the initial position of the rotor of a permanent magnet synchronous machine is derived based upon signatures in torque-ripple-induced vibration. Although requiring a vibration sensor, the method requires no knowledge of machine parameters, is applicable to both surface- and buried-magnet machines, and can be used under no load. Hardware validation has been performed using a surface-magnet machine, wherein a maximum error of 2.1deg (electrical) has been achieved using a start-up routine that requires 50 ms to complete