The Design And Implement Of AC Servo Syetem Based On DSP

The servo system has wide application in the field of home appliances and industrial control,it is mainly devided into two categories:the DC servo system and the AC servo system.The DC servo system has been widely used in the1970s for its excellent control performance.However, with the rapid development of microelectronics,power electronics and permanent magnet materials in recent years,especially the development and application of advanced control theory and strategy,the AC servo motor and AC servo sysytem has been completely match with the DC servo system in terms of their control performance.Thus, the AC servo system rises, and it replaces the position of DC servo system gradually. In the ranks of the AC servo system, due to modern permanent magnet materials’continuously improving performance and its continuously falling prices,PMSMs whose rotor are made by permanent magnet are widely used,and the AC PMSM servo system develope into the AC servo system mainstream gradually.This article describes the research background and related knowledge about AC servo system, including its composition, control methods, research status and trend,and it gives the mathematical model of AC PMSM in dq coordinate system on the basis of introducing several common coordinate systems.Then several different vector control strategies is presented on the basis of research on the mathematical model.After a comparative analysis of their own advantages and disadvantages, the id=0control strategy is chose. At last, an analysis of the basic principle and implementation of the space voltage vector pulse width modulation technology is given, it is one of the core part of this article.This article finishes the detailed hardware circuit and software design of the AC servo control system which is based on DSP. In terms of hardware circuit, a brief introduction to the control chip is done, then the eassy describes and designs the control circuit, the main power circuit and the detection circuit in detail. The system is a typical three closed-loop control structure,it uses the optical encoder to detect and velocity as the feedback signals in order to achieve closed-loop control of position loop and speed loop, and it also adopts a Hall sensor to detect and feedback the current signal for the purpose of achieving current loop’s closed-loop control.In aspect of the software design,the eassy first introduces the main funciton, and then gives detailed design description and program flow chart for all parts which include the PWM interrupt funciton, the rotor initial position determnation funciton, the speed calculation funciton,the SVPWM generation funciton and the PID controller funciton,especially an improvement with anti-windup algorithm for PID controller is done. Finally,the article completes the PCB design and it illustrates the key and difficuclt points in the PCB design process by combining the characteristics of this system;It also describes the integrated software development environment CCS and the function and use of IQmath function library;At last,the system debugging steps is given and the analysis of the phase current and PWM waveform is done.The result of the analysis shows that the sysytem meets the design requirements.