Fault-tolerant electrical drives have been mostly relegated to automotive, aerospace, marine and military applications where almost all types of fault must be tollerated and very good or rated performance must be guaranteed after a fault. Such requirements are satisfied only at price of multiple redundancies, at the hardware and control levels; obviously the more are the system redundancies, the greater are the efforts and costs needed to design and build a fault-tolerant drive.
However, many civil, commercial, and industrial applications would benefit from the availability of low cost fault tolerant drives even if they would be able to guarantee tolerance to the most common faults and limited performance after a fault.
Our experience lets us apply innovative fault tolerant solutions to standard and sensorless three-phase drives without requiring a complete redesign; by using a control-centered approach we can limit the amount of required hardware modifications so reducing cost and complexity.