Fault tolerant BLDC motor control for hall sensors failure

In most brushless direct current (BLDC) motor drives, there are three hall sensors as a position reference. This paper presents a method that allows the operation of a BLDC motor with one faulty hall sensor. The situations considered are when the output from a hall sensor stays continuously at low or high levels, or a short-time pulse appears on a hall sensor signal. For fault detection, identification of a faulty signal and generating a substitute signal, this method only needs the information from the hall sensors. So this method can be added as a standalone subsystem to existing drives. The paper provides many simulations on how the presented method reacts for various types of faults. An experimental evaluation is provided too. Due to the demand to operate at a high speed, the method is implemented into the FPGA.