Design Of Driving System Of Three-phase Hybrid Stepping Motor Based On DSP

Stepping motor is one kind of the most widely used motors in the field of industrial control, which has the advantage of low cost and simple driving system. With the development of high speed microprocessors, motor driving is moving towards the direction of fully digital. This dissertation designs a fully digital three-phase hybrid stepping motor(HB) driving system , which based on digital signal processor TMS320LF2407, to slove the vibration and noise of hybrid stepping motor at low freqency.Firstly, this dissertation analyzes the basic structure and running characteristic of the stepping motor. With the similarity between the stepping motor and the permenent magnet synchronous motor(PMSM), this dissertation gives the electromechanical equations under three different coordinate axes by ignoring the nonlinear factors of the motor, even establishs an mathematical model under d-q coordinate axes.Further more, this dissertation analyzes different kinds of driving methods, emphasises the necessity of the current subdivision driving to improve the permance of the stepping motor. With the similarity between the current subdivision and the voltage space vector pulse modulation(SVPWM); this dissertation analyze the practice of SVPWM on three-phase hybrid stepping motor in detail.Finally, this dissertation designs the hardware and software of this driving system and simulates this driving system. The design of hardware includes the design of main circuit and contorl circuit, which have the core of power drving and processor TMS320LF2407 respectively. The design of software includes the design of main procedure and the interrupted service procedure. According to the model established above, we can set up a simulation graphic in Matlab/Simulink, then we can simulate and analyze the phase current of stator and the step angle under different subdivision. Simulation indicate that SVPWM driving method not only can improve the starting frequcy and reduce vibration and noise of stepping motor, but also can improve the efficiency of the voltage, So the stepping motor can run steady.