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Reliable operation of dc–dc converters is vital for many applications. An appropriate converter monitoring scheme is required for fault detection and adoption of effective remedial strategies. Switch faults and degradation of electrolytic capacitor account for a considerable portion of the converter failures. Although rate of diode failures is not remarkable, power switch may be damaged in case of diode fault occurrence. Furthermore, for applications in which a redundant switch is employed as a remedy, it will be also endangered by diode failures if diode fault detection has not been considered in the monitoring scheme. Therefore, diode condition monitoring improves reliability of the converter monitoring approaches. This paper presents a simple diagnosis technique for open-circuit and short-circuit faults of the switch and diode in nonisolated dc–dc converters. The technique only employs diode voltage as the detection signature. The diode voltage and gate driver signal are processed in a simple logic circuit to generate some indicators for switch and diode fault diagnosis. Basis of the technique is discussed in detail. Several experiments have been carried out on buck, boost, and buck–boost converters. The results confirm the technique capability for switch and diode fault diagnosis in less than one switching cycle. [ABSTRACT FROM PUBLISHER]

Power switches and electrolytic capacitors are the most vulnerable components in the power electronic converters. Any failure in these components may result in severe damages, if no remedial action is employed. Prior to any remedy, the first step is fault diagnosis. In this paper, a new type of Rogowski coil sensor is proposed. The sensor captures the inductor current derivative, which contains suitable signatures for switch fault diagnosis and capacitor lifetime monitoring in nonisolated single-switch dc–dc converters. Using the captured signal, detection of switch open-circuit and short-circuit faults is realized by a simple logic circuit. Furthermore, a new capacitor lifetime monitoring technique is proposed, which employs this signal for calculating equivalent series resistance of the capacitor. The proposed sensor has some remarkable advantages. Due to its nonmagnetic core, the problem related to nonlinear response of magnetic cores at high frequencies will not be encountered. Furthermore, the proposed cost-efficient approach can be easily implemented even for already fabricated converters. The performance of the proposed sensor is evaluated using some finite-element simulations and experiments for a buck converter. The results confirm the capabilities of the sensor for switch fault diagnosis and capacitor lifetime monitoring in nonisolated single-switch dc–dc converters. [ABSTRACT FROM PUBLISHER]

Switched reluctance motors (SRMs) are extensively utilised in electric vehicles (EVs) due to some outstanding capabilities such as rugged and fault tolerant structure. Since the excitation of the phases is performed independently in the SRM, the motor could continue operation even in case of fault occurrence in one of the phases by disabling the faulty phase. However, to improve the reliability of the SRM for EV applications, an efficient fault diagnosis approach should be employed. In this study, an on-line method for detection of winding inter-turn short-circuit fault in the SRMs is presented. The proposed technique is based on a model, in which the extended Kalman filter is utilised. The method achieves a fast response, thus, the remedial strategies could be employed at the initial moments after fault occurrence. The proposed method is simple to implement and reliable in practice. The performance of the proposed approach is verified using some simulations and experiments. The results confirm high capability of the method in different conditions. [ABSTRACT FROM AUTHOR]