Study on Rotor Position Detection Implementation for On-the-fly Start-up Technique of a PMSM Drive without a Position Sensor

This paper describes a technique for the on-the-fly start-up of a permanent magnet synchronous motor without a position sensor. The technique uses resistive voltage divider sensors on motor phases usually built-in integrated drivers, thus no additional sensors are needed. The rotor position at speed is detected and monitored even if the power inverter is not activated. A smooth transition to active drive is enabled, removing the complete stop and align phase from the usual start-up sequence.