A novel PLL scheme for a sensorless PMSM drive overcoming common speed reversal problems

This paper shows the features offered by a novel Phase-Locked Loop scheme for observer-based sensorless control of permanent magnet synchronous motor drives. It will be explained how the particular error function characterizing the proposed solution enables to overcome common speed reversal problems affecting other more conventional PLL schemes. The principle of the algorithm is presented in detail and the integration with the overall sensorless strategy is shown. The main differences with a more standard solution are also highlighted through preliminary performance analyses, using both high-level PC and real-time simulations.