Dsp-based Research Of Control System Of Intelligent Electric Actuator

Electric actuator is one of the most important equipment in process control of modern industrial automation ,which receives the standard control signal (digital signal or analog signal) from the regulator and change it into the angular displacement or linear displacement output correspondingly.Finally,the valve will be driven movements by the BLDC,which makes the object adjustment automatically.In this paper,the status of domestic and international of electric actuator is analyzed carefully,one control strategy that the speed of BLDC motor and the position of valve control independently is posed,micro-controller technology, frequency conversion technology, intelligence communication and other advanced technologies are applied,and the intelligent electric actuator is developed with drive unit, control unit, intelligent communication, online digital display and the implementing agencies.The intelligent electric actuator developed in this paper includes main power circuit module, control circuit module and man-machine interface circuit module three parts.The main power circuit module consists of three-phase rectification circuit, switching power supply, intelligent power module IPM. Control circuit consists of the minimum system of DSP microcontroller, current detection and over-current protection circuit and the rotor position detection circuit. Man-machine interface circuit consists of the keyboard and display circuit, remote infrared control transmitter and receiver circuits.The system software is modular programming using C language whilch is developed in CCS3.3 environment with strong reliability, reusability, and portability. The system software Mainly consists of the software program the motor control system software program, the mode control program of the electric actuator and the program of man-machine interface and other components.The intelligent electric actuator developed in this paper has fast response, precise positioning and no overshoot,has torque and travel protection,has a wealth of online display and non-contact operation, makes the soft opening and soft closing, precise control of valve position and other key issues are solved. The experiment results show that position error of the valve be controlled less than±0.5%, ms-level response rate and have strong value and broad application prospects.