Sturdy Design of New Five-Phase Flux-Intensifying Fault-Tolerant Permanent-Magnet Motor Drive System for Healthy and Fault-Tolerant Sensorless Operation

Abstract

In this article, a sturdy design scheme of a new five-phase flux-intensifying fault-tolerant permanent-magnet (FIFTPM) motor drive system for healthy and fault-tolerant sensorless operation is proposed. Most previous studies regarding sensorless operation targets are improving the sensorless control strategy to enhance the estimated rotor position and ignore its performance under fault conditions. In this study, a solution to the aforementioned problems is devised by developing a sturdy design scheme from the perspective of motor design and control. With the special design to obtain the characteristic of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L_d</i> > <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L_q</i> and the little inductance variation under different operating conditions, the good sensorless capacity of the proposed FIFTPM motor can be achieved. Furthermore, because the structure of the FIFTPM motor drive system under fault conditions can be kept the same as that under healthy condition, the maximized simplification of the motor system can be realized. The resulting sensorless five-phase FIFTPM motor system presents good sensorless operating performances under both healthy and fault conditions, which is also demonstrated by the experimental results.