A Two-Step Strategy for Online Fault Detection of High-Resistance Connection in BLDC Motor

High-resistance connection (HRC) is one of the common stator faults in motors. The HRC fault detection method for brushless direct current motors (BLDCMs) has not been reported yet. This study proposes a two-step strategy for the detection, localization, and evaluation of HRC fault in a BLDCM. In the first step, the zero sequence voltage component (ZSVC) of the motor is acquired and analyzed, and the HRC fault can be detected from the amplitude of the fundamental frequency component of the ZSVC spectrum. In the second step, once the HRC fault has been detected, three indicators are calculated from the ZSVC and three-phase currents to localize the fault phase. The resistance value of the HRC is then calculated. Theoretical, simulated, and experimental analyses have been performed, and the results of them are consistent with one another, thereby validating the effectiveness of the proposed strategy. Both the HRC fault detection algorithm and the motor control algorithm are implemented on a single microcontroller unit in real time, which makes the proposed strategy efficient and flexible in industrial applications.