Luenberger Observer-Based Speed Sensor Fault Detection of BLDC Motors

Fault Tolerant Control Systems (FTCS) have become an important area of research for improving safety, reliability and efficiency of modern control systems. Generally, FTCS technique can be active or passive control. In this paper, the Fault Detection and Diagnosis (FDD) which belongs to the active control branch is used in order to detect faults that may occur in speed hall sensors of Brushless DC Motors (BLDC). The FDD methodologies, which depend on the process and the type of data available can be divided into two approaches; Model-based methods and data-based methods. Here, the proposed method focuses on the investigation of the use of Luenberger observer technique which belongs to the model-based approach. This observer depends on the residual signal which is used as a fault indicator in the overall system and represents the difference between the measured speed signal from the plant and the estimated speed signal. BLDC motor is selected as a benchmark for testing the proposed method due to the increasing demand for this type of motors especially in the renewable energy sector as in electrical vehicles, solar system, and new water pumping systems. The effectiveness of the proposed method is proved using MATLAB simulations and the results illustrate clearly the detection of faults as expected with high performance response.