Selection of Rotor Position Sensor Resolution for Variable Frequency Drives Utilizing Fixed-Position-Based Speed Estimation

The aim of this paper is to provide a simple and effective tool to determine the minimum resolution required from a rotor position sensor for variable frequency drives using fixed-position-based speed estimation. It is shown that it is possible to determine the minimum resolution based on the required bandwidth and phase margin of the speed control at the lowest operating speed. The effectiveness of the proposed method is then verified by means of dynamic stiffness analysis, performed in simulations and experimentally on a 3.6kW permanent magnet motor drive.