Broken rotor symptoms in the sensorless control of induction machine

Abstract

Purpose

The purpose of this paper is to investigate the need for a universal method for sensorless controlled induction motor drive diagnosis. The increasing number of sensorless control systems in industrial applications require a universal method for the drive diagnosis, which provides reliable diagnostic reasoning independent of control system structure and state variables measurement or estimation method.

Design/methodology/approach

Simulations and experimental investigation has been done with assumptions of multiscalar control system as a generalized vector control method, voltage source inverter application, sensorless control system based on selected speed observer structure and squirrel cage induction motor. Broken rotor symptoms are analyzed in the state variables and control system variables using DSP processing without outside measurement devices.

Findings

Symptoms of rotor asymmetry caused by broken rotor in the state and control variables was identified and symptoms amplitudes were compared. Based on the simulation and experimental results a new diagnosis method was proposed.

Practical implications

For early broken rotor detection there is a need to identify variables most sensitive to rotor asymmetry. In closed‐loop operation broken rotor symptom signals amplitudes are changed due to control system influence and in sensorless control due to used estimator frequency characteristics. The proposed method assumption is to aggregate symptoms in variables that altogether give results for broken rotor range regardless of applied control system structure or state variable estimator.

Originality/value

This paper shows control system influence to rotor fault symptom amplitudes in the state and control system variables. Identified phenomena is used for a new diagnosis method development.

Citation

Kołodziejek, P. and Bogalecka, E. (2012), "Broken rotor symptoms in the sensorless control of induction machine", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 31 No. 1, pp. 237-247. https://doi.org/10.1108/03321641211184940