Studv On Redundant Brushless DC Motor

This paper presents a redundant BLDC motor system topology based on four sub-motors. The sub-motors have separate three-phase stator win-dings and share the only rotor. The circuit of controller of sub-motors are separate. One sub motor’s fault has little influence on others, each sub motor operate independently and is a warm backup for others, the motor system have a good performance of fault tolerance.Firstly, based on the operating principle, the mathematical model of redundant BLDC is established, the feature of motor design is analyzed, the law of slots/ploes combination and the layout mothed of winding are researched. The electromagnetic program is designed by using Maxwell2D FEM software, and the magnetic field distribution, the back EMF, as well as the steady state performance of the motor are presented. Secondly, this paper introduces the dsPIC MCU control system of the redundant BLDC, the circuit of control module and power module of controller, the circuit of position machine,and the program flow chart of control system, are included. The position machine can independently give order to any sub motor for torque controlling. Thirdly, The co-simulation model of red-undant BLDC motor system is built by using Maxwell2D and Simplorer simulation platform. When different number of sub motor is running, the performance of motor system is described in detail. Besides, the research on torque compensation method with fault status such as open-circuit and short-circuit in one sub-motor are carried out, which demonstrate a good performance of fault tolerance of this motor system topology. Finally, the prototype of redundant BLDC is built. Combined with the control system, the experimental platform is also established. The experiments are made to demonstrate the performance of steady state and fault tolerance of redundant BLDC motor system.