Fault Diagnosis and Signal Reconstruction of Hall Sensors in Brushless Permanent Magnet Motor Drives

Brushless permanent magnet (BLPM) motor drives based on Hall sensors have received extensive attention in the literature and are widely used in many applications. However, most of the available and published controllers assume that the Hall signals are always available, which is not true if any of the sensors are faulted. In this paper, several fault-tolerant control schemes for BLPM motor drives are proposed. The methodology is based on fault diagnosis and its classification, and subsequent signal reconstruction. Simulation and experimental results demonstrate the effectiveness and advantages of the proposed fault-tolerant schemes in restoring the motor operation when failures occur in up to two Hall sensors. The proposed fault-tolerant schemes can be easily and flexibly realized for conventional drive systems, either by adding the code in the existing driver or by adding a simple auxiliary circuit between the Hall sensors and the driver.

I. Introduction

Brushless permanent magnet (BLPM) motors are widely used in many industrial and automotive applications [1]. Although many sensorless control methods have been proposed for BLPM motor drives [2], such approaches have apparent limitations in the startup performance, speed range, and additional cost. Therefore, BLPM motor drives with position sensors are used very widely [3]–[10] . Compared with high-resolution encoders and resolvers, Hall sensors have considerable advantages of low cost and simplicity making them particularly useful for compact and inexpensive motor drives [11]. Consequently, Hall-sensor-based BLPM motor drives are also widely used, including nonsinusoidal current drives as brushless dc (BLDC) motors and sinusoidal drives as permanent magnet synchronous motors (PMSM) [10]– [13].