Percorrer por autor "Cardoso, A. J. Marques"
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- A new diagnostic technique for real-time diagnosis of power converter faults in switched reluctance motor drivesPublication . Marques, Jorge F.; Estima, Jorge O.; Gameiro, Natália S.; Cardoso, A. J. MarquesAccurate fault identification allows the adoption of procedures that minimize the fault impact on the machines operation. Switched reluctance motors (SRMs) have been recognized for their fault-tolerant capabilities and they present a very robust configuration, particularly due to the absence of windings or magnets in the rotor. All these attributes make the SRM a competitive solution for aircraft and automotive applications, where systems reliability is a crucial feature. Therefore, in this paper, a new algorithm for real-time diagnosis of power converter faults in SRM drives is proposed. In contrast to other methods that use additional sensors or devices, the presented technique uses the measured phase currents only, which are already available for the drive control. The proposed algorithm effectively detects the inverter faulty phase and is capable to localize the faulty power switch. Power switch open-and short-circuit fault occurrences in an asymmetric full-bridge converter are considered and analyzed.
- The partial average power as a fault diagnostic parameter applied to SRM drivesPublication . Gameiro, Natália S.; Cardoso, A. J. MarquesA new fault diagnostic parameter, applied to switched reluctance motor drives, is presented. The proposed parameter is a partial average power based on the power converter supply current and the rotor mechanical position information. At high speed operating conditions phase current is not regulated and the machine closed-loop control only needs to observe one current, which is the power converter supply current, in order to avoid excessive current amplitudes. The adopted control strategy is clearly explained. Several simulation results are presented and discussed considering different operating conditions. The normal operation, a fault occurrence in a power switch and a sudden mechanical load decrease are analysed. The simulation results permit to validate the proposed partial average power as an appropriate parameter for the diagnosis of an open-circuit fault in a power switch.
- Power converter fault diagnosis in SRM drives based on the DC Bus current analysisPublication . Gameiro, Natália S.; Cardoso, A. J. MarquesThis 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.