Constant current control of stepper motor in microstepping mode using PIC16F877A

This paper presents a microstepping stepper motor with constant current control algorithm for a precision positioning system. An open loop microstepping controller has been developed without position feedback. A constant current control algorithm has been designed with the feedback current to maintain the phase currents constant at any desired level. The current regulation of PMSM results in improvement of positioning accuracy of the system. The system has been simulated using MATLAB-SIMULINK and the controller has been implemented using low cost PIC16F877A microcontroller. The simulation and experimental results depict the effectiveness of the controller.