永磁交流伺服系统中速度环的优化设计

针对永磁交流伺服系统中速度环的设计,分析了采用传统PI调节器的不足之处,进而引出变结构思想以提高伺服系统的快速响应能力。该方法虽能保证系统的快速响应,但速度超调不可避免,为此引入了微分负反馈,以提高抑制超调量的性能。但微分负反馈的引入会影响伺服系统的制动效果,使电机出现"爬行"现象。利用变结构与微分负反馈结合的方法可避免"爬行"现象的发生。仿真和实验均证明,采用带微分负反馈的变结构PI调节器,可使系统既有较快的响应速度,又能明显地抑制伺服系统的速度超调,还能解决电机制动时的"爬行"问题。

Optimization Design of Speed Loop for PMSM Servo System

According to design of speed loop for PMSM servo system,this paper analyzes the shortage of traditional PI adjustor.Then the idea of variable structure is presented for improving the ability of rapid response of servo system.The method ensures the system has rapid response characteristic,but the speed overshoot is hardly avoided.Therefore,the method of differential negative feedback is introduced to improve the ability of reducing overshoot.However,introducing differential negative feedback influences braking effect of servo system.The crawling phenomenon of motor takes place.Lastly making use of the idea of variable structure combined with differential negative feedback prevents the emergence of crawling.Both the numerical simulation and experiment approve that the variable structure PI adjustor with the idea of variable structure combined with differential negative feedback not only can effectively quicken the speed response and obviously reduce speed overshoot, but also can solve the crawling phenomenon during motor braking.