Operation of PM BLDC motor drives with faulty rotor position sensor

PM BLDC motors belong to a group of machines using electronic commutation. The selection of windings supplied with power depends on a rotor position which can be determined in a number of ways. Very frequently method is using optical or Hall effect two-state sensors fixed on motors. In the case of a sensor fault, when the sensor output signal remains unchanged, drive operation is significantly deteriorated and it is necessary to take actions ensuring further flawless operation of a drive in accordance with of the idea of fault-tolerant systems' operation. The paper presents the results of experimental research related to the reproduction of rotor angle position used after the detection of a rotor position sensor error.