All-digital, Two-phase Hybrid Stepper Motor Drives The Development,

Two-phase hybrid stepping motor is a kind of motor widely used in industry control. It has the advantage of low cost and simple drive system. With the developments of high speed microprocessor and power converters technology, motor control is moving towards fully digital direction. Therefore, the research of the fully digital driver for two-phase hybrid stepping motor is very important.First of all, the author introduced the components of stepping motor system and then presented the development survey of all kinds of technologies related to stepping motor system, analyzed the working principle of stepping motor, illustrated its mathematical models, studied the theory of vector control on hybrid stepping motor further deeply, and then developed a kind of control scheme of the fully digital driver for two-phase hybrid stepping motorAs for hardware, as the stepping motor's wirings have middle terminals, a special power circuit was designed and IR2110 is used to drive the power circuit. TMS320LF2407A is used as the core of the control unit, which outputs PWM to drive power circuit. According to the character of DSP and the power circuit, current feedback circuit and over current protecting circuit were designed. So a hardware platform for the driver's scheme was finished.As for software, the control algorithm of stepping motor was implemented by DSP program. It adopted the max-current/torque vector control method to realize the decoupling control of hybrid stepping motor. The general PI control method was used in current loop and SVPWM modulation was used in the inverter. Furthermore, in order to satisfy the requirement of convenient operation and monitoring, the monitor program on PC is also presented.At last, the sample machine was tested. Noisy characteristic and torque characteristic in different frequency in different subdivision setting were analyzed. The results of experiments proved the feasibility of the scheme and show that the design of the fully digital driver of two-phase hybrid stepping motor is reasonable, performance is reliable, and has good application prospect.