Research And Design Of Subdivided Driving System For Three-Phase Hybrid Stepping Motor

Based on the model of a three-phase hybrid stepping motor, the torque expression is deduced. The effect of subdivided driving on operating performance is analysed. It is illustrated that sine wave subdivided driving can make stepping angle and torque equal. This paper proposes a new method to obtain any wanted stepping angle with adjustable and even subdivision. With the method, the stepping angle isn't restricted with different phase number and tooth number any longer. So the product arrangement of stepping motors and drives can be simplified. And the efficacy of the system is taken full advantage of.Based on the PWM technology (the style of traced SIN current) with fixed switch frequency, a SIN subdivided driving system for three-phase hybrid stepping motor has been built. Both software and hardware are synthesized. Three-phase bridge inverter used, the current in each phase is made similar to sine wave using current closed loop control. Because of the complicacy of the circuit, all sorts of influencing factors, such as power and high frequency modulation etc., are considered to strengthen the harmony and the noise-immunity of the system, while the printed circuit board is designed.The driving system is controlled with microprocessor. It is easy to realize SIN even subdivided driving and to obtain any wanted stepping by programming. Motion controlling can be integrated with driving. According to the optimised curve of acceleration and deceleration, the moving control can be achieved by the drive. So the difficulty of system integration is lessened. The drive with single microprocessor is used to control the two stepping motors in a two-axis stepper motion system atthe same time. So the cost is reduced and the produce device is simplified. Finally, this paper presents the experiment result, including the output current and the driving effect using different micro-step number.The driving system operates for a long time in the numerical control system. Due to the driving system, noise and vibration are restrained. The positioning accuracy and the harmony of the position control system are also increased.