TOLERÂNCIA A FALHAS EM MOTORES DE RELUTÂNCIA VARIÁVEL COMUTADOS

Publications

Supply current polar chart analysis of SRM drives under normal and faulty operating conditions

Publication . S. Gameiro, Natália; A. J. Marques Cardoso

A polar chart of the power converter supply current, comprising phase currents and rotor mechanical position information, is presented, in order to characterize the dynamic operation of a SRM drive. Power converter supply current can be used as additional information of extreme importance when a sensor error or failure occurs. Its analysis is then important and permits to develop appropriate fault tolerant control strategies to solve failures or errors on phase current measurements. Time-domain waveforms of the phase currents and power converter supply current are presented and discussed. Two different speed operating conditions examples are presented, in order to understand the differences on SRM dynamic behavior in the all speed range. For both situations, the normal and the faulty operation due to the absence of one motor phase are analyzed. The adopted SRM control strategy, based on the electromagnetic torque regulation, is clearly explained for the all SRM speed range.

2009-03Conference paper

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Power converter fault diagnosis in SRM drives based on the DC Bus current analysis

Publication . Gameiro, Natália S.; Cardoso, A. J. Marques

This paper presents a new fault diagnostic technique applied to switched reluctance motor (SRM) drives. A fault is detected when the measured amplitude of the DC bus current differs from its expected amplitude, assuming normal operating conditions. The information about phase currents amplitudes and the control states of all power switches permit to easily estimate the amplitude of the power converter supply current, since an asymmetric bridge converter is used. Open-and short-circuit fault occurrences in the converter power switches are presented. The proposed technique can early detect these fault occurrences and can also, in almost situations, identify not only the affected motor phase but also the faulty element. A short-circuit fault in a converter power switch of a SRM drive does not necessarily causes a short-circuit in the DC bus, unlike to what happens in many other converter-fed electrical machine drives. On the other hand, although a converter power switch open-circuit fault can be easily detected by the observation of the phase currents, the identification of the faulty element becomes impossible to achieve, if only phase currents are measured. This information is of paramount importance in the development of fault tolerant power converters.

2010-09Conference paper

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