Fault tolerant rotor position and velocity estimation using binary Hall-effect sensors for low cost vector control drives

High-resolution position and velocity estimation algorithms based on binary Hall-effect sensors for low-cost vector control drives have been the subject of significant research in recent years. While different estimation algorithms have been proposed and analyzed, no contribution so far has dealt with Hall-effect sensor faults and their repercussion on the drive. This paper intends to fill this gap by analyzing single and multiple Hall-effect sensor faults and by proposing a method to detect, identify and mitigate such faults. The method is general, it ensures proper operation of the drive and is not dependent on the particular estimation algorithm that is used; by way of example, here it will be applied to a vector-tracking observer. Limitations on the performances of the faulty system are discussed and experimental results are reported to confirm the theoretical analysis.