Open Phase Fault Tolerant Control of Multi Three Phase Machines

Drive system availability is critical in aerospace applications. Multi three phase machines are a known solution to provide redundancy and fault tolerance capability. Control of multi three phase machines is typically implemented in DQ domain or VSD domain. An alternate control approach is per phase current control using proportional resonant controllers in ABC domain. In this work, ABC domain current controllers are utilized to demonstrate key advantages in high reliability applications - fault reconfigurability with minimal controller modifications and ability to control multiple harmonic components. ABC domain control structure enables seamless transition from healthy mode to fault mode with only algebraic operations at the controller output unlike DQ/VSD domains. Furthermore, single-phase operating mode in ABC domain provides an additional fault mode for emergency operation which is unavailable in DQ/VSD control domains. The Fault mode operation under open circuit fault of one phase in each winding set is demonstrated. Simulation and experimental results validate the normal and fault condition operation of the proposed control method.