An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 2) VOLTAGE PROFILING <s> The paper identifies and analyzes a number of severe fault conditions that can occur in the switched reluctance machine, from the electrical and mechanical points of view. It is shown how the currents, torques, and forces may be estimated, and examples are included showing the possibility of large lateral forces on the rotor. The methods used for analysis include finite-element analysis, magnetic circuit models, and experiments on a small machine specially modified for the measurement of forces and magnetization characteristics when the rotor is off-center. Also described is a computer program (PC-SRD dynamic) which is used for simulating operation under fault conditions as well as normal conditions. The paper discusses various electrical configurations of windings and controller circuits, along with methods of fault detection and protective relaying. The paper attempts to cover several analytical and experimental aspects as well as methods of detection and protection. > <s> BIB001 </s> An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 2) VOLTAGE PROFILING <s> This paper presents a novel method for diagnosis of eccentricity in a switched reluctance motor (SRM). The method employs two-dimensional finite-element analysis to calculate mutual fluxes and mutually induced voltages in an 8/6 SRM. An investigation of the effect of static eccentricity on these quantities shows that eccentricity has a considerable effect on them. Since flux measurement is costly, the method introduces mutual voltage as a suitable criterion for diagnosis of eccentricity in SRMs. <s> BIB002 </s> An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 2) VOLTAGE PROFILING <s> In this paper, a comprehensive method for eccentricity fault diagnosis in switched reluctance machines (SRMs) during offline and standstill modes is presented. This sensorless method is able to detect occurrence, location, direction, and severity of the eccentricity fault in SRM. First, the theory of the method is presented, and then its background formulation is explored and discussed. In order to model the eccentric SRM and apply the test method, a 3-D transient finite-element method (3-D TFEM) is employed, which takes into account all physical and geometrical characteristics of the motor components. Next, a test rig is established to carry out various measurements on a faulty motor with different degrees of eccentricity. Then, a procedure of diagnosis method with achieved data is described. In this regard, this method investigates how the fault location as well as the faulty phase in the SRM can be detected. Furthermore, the strategy of the fault direction detection based on induced voltage variations is stated. In addition, a proper index will be proposed in order to detect the fault severity. To demonstrate the merits of this indicator in the eccentricity detection and estimation of its severity, the correlation between the index and frequency and voltage variations are evaluated. <s> BIB003
Provided that the partial or whole pole winding is shorted, the magnetomotive force generated by opposite pole winding will be different, and thus the produced voltage will be different. In BIB001 , the short-circuit fault can be detected and located based on measuring the differential induced voltage of opposite pole winding with search coils depicted in Fig. 10 . Eccentricity fault influences the air gap between the stator and rotor, which means that mutual fluxes contain eccentricity information. The numerical analysis of mutually induced voltage can also be used for eccentricity fault diagnosis BIB002 . It is confirmed that the amplitude of the produced voltage under chopping current control is also suitable for diagnosis of eccentricity fault. This method can be implemented without stopping the motor. Another eccentricity fault detection strategy is investigated in BIB003 , where two test signals with opposite phase are injected into two coils of the aligned-phase winding. The amplitude of the induced voltages sensed from the other two phases will be different and will increase or decrease along with the degree of the eccentricity fault. However, this method can be implemented only when the motor is in stationary condition with one phase fully aligned.