Switched reluctance direct drive with integrated distributed inverter

This thesis proposes a new concept of an integrated and distributed inverter for switched reluctance machines. Due to the integration, the terminal connections are independent of the number of phases, and thereby reduced to only provide dc-link power, communication and cooling. This simplifies the integration of the drive in the vehicle, hence, reducing complexity and costs of the drive system. The concept of the distributed inverter involves the use of one separate inverter module for each coil. Consequently, the integration of machine and inverter is simplified, the heat losses of the power devices are distributed equally among the circumference of the machine, simplifying the cooling, and finally the redundancy of the drive is increased significantly. Due to the modularization of the inverter, each coil is electrically decoupled from the other coils of the machine, even within one phase. Therefore, the remaining inverter modules can continue operation if one module fails. The capability to continue operation of a drive after a fault is of great interest, particularly in the area of military, aerospace, automotive and railway transportation industries. In those applications, it is tolerable that the machine continues operation with reduced power after a fault. This so-called limp-home capability avoids all the inconveniences of a standstill in case of a fault. To guarantee safe operation in the case of different faults in one particular machine this thesis analyzes the influences of faults of single modules on torque ripple, net radial force and vibrations of the machine and therewith suitable fault-tolerant control strategies are developed.