Fast Fault-Tolerant Control for Improved Dynamic Performance of Hall-Sensor-Controlled Brushless DC Motor Drives

The Hall-sensor-controlled brushless dc (BLDC) motors are often considered in low-cost applications due to their simplicity of control and good performance in a wide range of operating conditions and speeds, where they still may be preferred over more complicated sensorless controls. Due to a possible failure of Hall sensors, there has been an increased interest in fault-tolerant-control (FTC) in the literature. However, most established FTC methods are not capable of fast fault diagnosis and compensation, which may lead to degradation of dynamic performance, especially during transients. This article proposes an improved fast FTC (FFTC) that obtains fast identification and compensation of asynchronous or simultaneous faults of up to two Hall sensors. The proposed FFTC method is validated experimentally and shown to maintain continuous operation even under extreme dynamic accelerations and sudden load variations, which are the advantages over alternative FTC methods.