High Accuracy Drive And Control System Of 2-Phase Hybrid Stepping Motor

This dissertation is about a fundamental research which undertakes by REMP Electrical Machine & Control Technology research institute, Based on the characteristics and the work principle of stepping motor, the paper emphasizes the drive and control technology of stepping motor.This article analyzes the structure and the work principle of 2-phase hybrid stepping motor, establishes a nonlinear dynamic model, and also presents the expression of the winding flux linkage equation, rotation voltage equation, the rotor equation of motion and the transfer function.According to the character, the paper uses subdivision control technology, which is based on current vector even rotation with constant amplitude, to control the exciting winding current and to produce rounded and even inner complex magnet field. The value of complex magnet field vector decides the value of motor torque;the neighboring two complex magnet field vectors decide the value of step angle. Through analyzing and establishing the subdivision model, this paper controls the winding current reasonably, and guarantees constant magnetic field value, even angle. A driver for 2-phase stepping motor is designed.The driver takes single chip AT89C51 as the control core, selects DAC0832 and the H-bridge as the driver circuit. The paper discusses the technology of driver, the hardware and software designing in detail. In order to ensure A phase and B phase circuits are symmetric, digital potentiometer X9C503 with exterior pressed key in the feedback amplification circuit is designed.Using subdivision control technology, the motor operates smoothly, the operation precision is increased and the torque is constant. The range of subdivision can be regulated from 1 to 256 only by changing the current waveform value in the memory.A last, a whole test for driver is made. The experiment result indicates that this driver reaches the qualities required. The system runs smoothly and safety. The circuitis simple, and has a good performance. The design principle fits many kinds of stepping motor, and has a good practical value.