Acionamento de motor síncrono a ímã permanente sem sensor de posição rotórica.

Abstract

The permanent magnet synchronous motor has important features for high performance drive such as high efficiency and power / volume ratio. Control of this type of machine requires the use of a position and / or speed sensor. However, the use of this sensor represents constraints on the drive system such as cost and reliability. Elimination of the position sensor by position estimation techniques has been an area of ​​intense research. Generally speaking, the techniques are divided into two categories: techniques based on magnetic protrusions, designed for low speed. Notably, each category has advantages and limitations depending on the operating speed. Initially, a comparative study of the high frequency voltage injection techniques used for low speed position and / or velocity estimation is presented. In this scenario, this work proposes an evaluation of the upper operating limit for a position estimator based on the evaluation of the AC harmonic content of the q axis reference current as a function of the position observer speed and bandwidth. In addition, the paper presents a proposal for the determination of the transition region between rotor position estimators. The study applies the transition between the responses of two position estimators. At low speed, high frequency voltage is applied to the stationary frame to track the magnetic protrusion. For high speed, a state filter is used to estimate the counter electromotive force. Based on the established criterion, the bandwidths of the position observers are defined as a function of speed. Simulation results and experimental results of the performed studies are presented and analyzed.