直驱式系统中交流调速系统的设计

Design of AC Speed-Regulating System Applied in Direct Drive System

在大功率、大容量的自动控制系统中大量使用液压系统。传统液压系统中电机不可调速,而是通过伺服阀和变量泵来实现控制输出,性能有限。而直驱式系统采用可调速电机和定量泵代替了传统液压系统的不可调速电机和伺服变量泵,不光极大的提高了系统的性能,还可以简化结构,提高可靠性和经济性。直驱式系统实现的关键在于交流调速系统,因此本文分别对基于交流异步电机和同步电机的调速系统进行了研究。先简要介绍了交流调速的发展和背景,然后提出交流电机的数学模型的特点,再介绍了矢量控制理论和坐标变换的原理以及matlab仿真模块的搭建。最后通过仿真和实验交流异步电机和交流同步电机调速系统,可以分析得出结论 :同步电机的调速系统的快速性、通频带等性能指标比异步电机的更好,在直驱式系统中应用同步电机调速系统是更好的选择。

Hydraulic system is widely used in automatic control system of high-power and high-capacity, in traditional hydraulic system the motor can not control speed, in order to control systems＇ output, it can only use variable valve. The performance is limited. The direct drive system,which is composed of hydraulic pump driven by AC motor and executive elements, replaces the no-speed-control motor and variable valve with speed-control motor and constant rate valve. It can not only improve system performance, but also simplify architecture, improve reliability and economic. So this paper researches both permanent magnet synchronous motor AC servo system and induction motor AC servo system. In the first place this article introduces the development and the background ofAC servo system. Then points out AC motor＇s characteristics. In addition, detailed descrips the theory of vector control, coordinate transform, space vector pulse width modulation inverter and builds simulation model. At last, through simulation and experiment, the conclusion can be drawed that： synchronous motor is better than the PMSM induction motor in rapidity, pass band and so on. Synchronous motor based AC servo system is more suitable for the direct drive system.