Observability analysis of sensorless synchronous machine drives

TL;DR

This paper analyzes the local observability of synchronous machines to improve sensorless control, proposing a unified approach and a high-frequency injection technique to enhance operation at standstill.

Contribution

It introduces a unified observability analysis for various synchronous machines and proposes a high-frequency injection method to improve sensorless control at standstill.

Findings

Unified observability analysis applicable to multiple machine types

Identification of conditions affecting sensorless control performance

Proposed high-frequency injection technique enhances standstill operation

Abstract

This paper studies the local observability of synchronous machines using a unified approach. Recently, motion sensorless control of electrical drives has gained high interest. The main challenge for such a technology is the poor performance in some operation conditions. One interesting theory that helps understanding the origin of this problem is the observability analysis of nonlinear systems. In this paper, the observability of the wound-rotor synchronous machine is studied. The results are extended to other synchronous machines, adopting a unified analysis. Furthermore, a high-frequency injection-based technique is proposed to enhance the sensorless operation of the wound-rotor synchronous machine at standstill.