Distributed control architecture for IMMD that coordinates all of the independent phase-leg controllers, providing robust control properties and fault tolerance
The integrated modular motor drive (IMMD) requires a special controller architecture that is appropriate for the modular phase drives. Each of the individual pole-drive units has its own local controller for managing its flux and torque contribution. These controllers are designed to coordinate the excitation waveforms of the multiple pole-drive units in order to produce rotating flux waves in the machine air gap as needed to achieve torque control. A promising heterarchical control configuration has been developed in which all phase modules run the coordination algorithm in addition to their local control algorithms. Based on the information obtained from the other modules, each module determines what its own action has to be. This controller configuration offers opportunities for robust operation in the event of faults in one or more of the phase-drive units, allowing the remaining healthy units to continue operation. This architecture also provides opportunities for the healthy phases to adapt their winding excitation waveforms in order to extract the maximum possible post-fault average torque with reduced ripple torque.