Active real-time tension control for coil winding machine of BLDC motors

This paper proposes a new active tension system which is used in coil winding machine for BLDC motor manufacturing. A comparison of winding condition between normal coil such as round shape coil, rectangle shape coil and BLDC coil is presented. To overcome the harsh winding condition of BLDC coil winding, a new wire accumulator is proposed to store or release a wire when the wire is stretched or sagging. Wire accumulator consists of a pneumatic cylinder which is driven by a servo valve and a spring. The system modeling result shows that this tension system is a MISO system. The traditional PID controller is adopted and drives the real tension according to the given reference tension. In order to evaluate the effectiveness of wire accumulator and the performance of the proposed controller, some simulation results are carried out.