<p>When the power device of the wind turbine yaw inverter experiences an open-circuit fault, the yaw system’s alignment with the wind will not be affected in the short term. Additionally, the encapsulated power devices are difficult to detect during regular high-altitude inspections making yaw converter failures highly concealed. If the fault is not detected early, it may lead to secondary faults in the converter and potentially damage the yaw motor. Considering the feasibility of engineering application, the rapidness of the diagnostic process and the ability to resist interference, an open-circuit fault diagnosis method of yaw inverters based on current vector magnitude and phase interval is proposed. Firstly, considering the characteristics of yaw operation, the three-phase current data outputted by the inverter, collected from the initiation of yaw until just before the yaw speed reaches its maximum, is utilized to obtain the magnitude and phase information of the current vector through the Clarke transform. Secondly, by setting a threshold for the standard deviation of the current vector magnitude, the identification of open-circuit faults in the inverter is achieved. Subsequently, feature quantities are constructed based on the current vector phase interval to locate the open-circuit fault in the inverter, enabling the diagnosis of single-switch and double-switch open-circuit faults for yaw inverters. Finally, the effectiveness of proposed method is validated through simulation and physics experiments. Research indicates that the proposed method requires no large number of fault samples and, with simple threshold settings, can accurately identify and localize 21 types of open-circuit faults in yaw inverters, under both noise interference and varying load conditions.</p>