The switched reluctance machine (SRM) is receiving renewed attention as a viable candidate for various adjustable speed and high torque applications such as in the automotive, traction and aerospace industries. The unique feature of a SRM is its relatively simple mechanical structure; the rotor does not carry any windings, commutators or permanent magnets. The maintenance free usage makes it a good choice over other DC or AC drives.
The software modeling and hardware testing of SRM, for four-quadrant operation, and the development of an optimum commutation angle controller for low output current ripple, and efficient battery charging using the switched reluctance generator (SRG) is presented in this thesis. Two different SRM models are simulated for controller development. One of the models is the geometry based machine model by A. Radun, which is used to develop the operation logic for four-quadrant control of a three-phase 12/8 pole SRM. The second model is based on torque and flux data generated through finite element analysis using the software Flux2D for the three-phase 12/8 SRM. Simulation results obtained from the models were used to develop a control strategy to adapt the commutation angles in real-time for efficient battery charging with minimized current ripple. Two digital controllers namely, the turn-on angle controller for regulating the charging current and the turn-off angle controller for minimizing current ripple (adjusting algorithm) are developed to deliver the desired output power. The controller algorithm is implemented in a TI digital signal processor (DSP) for real-time controls. The SRM power and control hardware cards are integrated into a complete SRM drive system for experimental verification. The experimentally obtained commutation angles are compared with the data table generated from simulation results.