Fault Diagnosis and Compensation Strategy of BLDC Motor Drives with Hall Sensors

In a brushless DC motor drive system, two fault diagnosis methods were proposed in order to investigate the faults of Hall position sensors, and the corresponding compensation strategy was carried out. Firstly, the differences of Hall signal sequences during normal and fault situation of motor were analyzed, then a fault diagnosis method based on the characteristics of Hall signal sequences was proposed. In order to detect the faults of Hall position sensors in real time, a sliding mode-based super-twisting speed observer was established and combined with the Hall signal sequences. Under fault situations, the compensation controller was established, and a second-order speed prediction method was used to generate the compensation Hall signals of the faulty sensors. Finally, theoretical analysis and experiments demonstrate the effectiveness of the present fault diagnosis methods and compensation strategy.