Fault-tolerant control architecture for an electrical actuator

In safety-critical applications fault-tolerant electric drives and motors can be used. To avoid compromising the reliability of the drives and isolated motor windings, the control hardware must also be fault tolerant. In this work control hardware is separated into lanes, each with a designated power supply, electric drive, motor phase winding and position feedback sensor, all packaged into a single assembly. For a system to operate with a faulted lane, lanes must be able to cross-compare data and determine whether a lane has failed. A demonstrator controller drive has been produced for a multiple lane actuator with the ability to detect a failed lane and continue operation. For the first time, current shaping is implemented on a working prototype to produce instantaneous torque control, even in the event of a fault. This permits rated torque at all rotor positions when stationary and when rotating slowly and rated mean torque at high speeds, when the inertia of the system lets the drive ride through torque dips caused by the faulted phase.