An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 4) COORDINATES TRANSFORMATION <s> This paper presents a fault identification and tolerant method for switched reluctance motor (SRM) drives. The reliability of a power transistor in a power converter is the source of most problems in several industrial applications. It is critical to correctly diagnosis the faults occurring in a drive system to avoid harmful accidents and to ensure continuity of operation. In this paper, two types of faults, namely, short- and open-circuit faults, are analyzed on the basis of the current patterns of the power transistors of SRM drives. A fault is detected when the measured amplitude of the current differs from that of the normal-state current. A fault-tolerant scheme is applied according to the type of fault. Simulations and experiments are performed on a 1.0-kW SRM drive. The results are presented to verify the validity of the proposed method. <s> BIB001 </s> An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 4) COORDINATES TRANSFORMATION <s> This paper presents a new fault-tolerant technique, on the basis of the current Park's vector, which is applied to switched reluctance machine (SRM) drives. Open- and short-fault occur in the power converter switches. A proposed current Park's vector can diagnose these faults. In addition, A position of the short-fault in the asymmetric bridge converter can be detected using the proposed another method. The fault-tolerant controls are performed after a fault diagnosis. An open-fault tolerant control can perform considering the adjacent phase switches. A short-fault tolerant control can perform using remaining switch of fault phase. These fault occurrences can be identified in the affected motor phase. A simulation is performed with a four-phase SRM drive system, and the results are presented to verify the validity of the proposed method. <s> BIB002 </s> An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 4) COORDINATES TRANSFORMATION <s> In this paper a new on-line fault diagnostics technique of the occurrence of stator faults in an 8/6 Switched Reluctance Motor is proposed. To validate the proposed approach a dynamic model was developed in Matlab/Simulink environment, based on the utilization of a specific lookup table for each phase, obtained with FEMM. <s> BIB003 </s> An Overview of Fault-Diagnosis and Fault-Tolerance Techniques for Switched Reluctance Machine Systems <s> 4) COORDINATES TRANSFORMATION <s> In this paper the inter-turn short-circuit fault diagnosis in a 4-phase 8/6 Switched Reluctance Motor is addressed. A new on-line technique for the diagnostics of the occurrence of inter-turn short-circuit faults at an early stage of development is proposed. The validation of the proposed approach is based on a dynamic model, developed in Matlab/Simulink environment. <s> BIB004
In AC machines, Park transformation is widely employed in fault diagnosis BIB003 . In BIB001 , phase currents of SRM i a , i b , i c , and i d are transformed to i ds and i qs through (11) and (12), known as d-q current patterns. where i a , i b , i c , and i d are the currents in the four-phase SRM; i ds and i qs are the transformed currents in d-q axis. Different current patterns contain open-circuit or and shortcircuit faults information. In the normal state, the current trajectory is a circle going counterclockwise. In the fault condition, the trajectory deviates from the normal shape. This feature distinguishes faulty and healthy conditions clearly without any additional switches or diodes. Not only phase currents but also drive signals can be transferred in d-q axis to detect inter-turn faults, given by where G A , G B , G C , and G D are the drive signals of the chopping switches. The mean values of the transferred drive signals G d and G q is not equal to zero in the inter-turn short-circuit fault BIB004 . The d-q transformation and current trajectory method are also employed in BIB002 to detect openand short-circuit faults called current Park's vector method.