Sensorless control system for high-frequency synchronous motor with incorporated magnets based on combined method of position estimation

Abstract

The known methods to estimate the position in drives based on synchronous motors with incorporated magnets have significant limitations in accuracy and noise immunity at high frequencies of the main voltage harmonic. Due to the requirements to improve the weight, size, and cost indicators of electric drives, it is relevant to design a sensorless synchronous drive operating with frequencies from 0 to 1000 Hz and more in the presence of a wide 5…10:1 speed control zone with a constant nominal power. The results of the study are based on the analysis of theoretical and experimental data obtained by other authors, as well as computer modeling in the Delphi software environment. The initial information for the simulation is obtained from the technical description guide and data of a full-scale experiment on a real-life object. A vector control system has been developed for a high-frequency synchronous motor with incorporated magnets without a mechanical coordinate sensor based on a combination of speed and position estimation methods by means of high-frequency injection and EMF calculation. The study of the developed system is carried out by means of modeling, considering the influence of interference in the measuring channels and the effect of cross-saturation of the magnetic circuit. The proposed structure and control algorithms have provided operability and high-quality control indicators sufficient to design a traction drive with a maximum frequency of 800 Hz or more and an area of operation in a constant rated power mode of at least 8:1 with a signal-to-noise ratio characteristic of typical current sensors.