基于LabVIEW的直流电机控制的建模与仿真

Modelling and Simulation of Direct Current Motor Control Based on LabVIEW

自从美国国家仪器公司(national instruments,NI)提出了虚拟仪器的概念之后,诸多虚拟仪器产品便在电机控制中得到了日益广泛的应用。LabVIEW是NI公司为开发虚拟仪器提供的一种图形化编程语言,极大地方便了用户对各类虚拟仪器产品的开发。采用两种方法在LabVIEW中实现了直流电机控制的建模与仿真,分别是状态方程数值解法和传递函数法。使用状态方程数值解法构建的电机模型实现了电机的开环启动仿真;使用传递函数法构建出了完整的转速、电流双闭环直流调速系统模型。然后在其基础上又加入了反电动势、励磁电流的双闭环,实现了基速以上的弱磁调速,使得调速范围变大且系统稳定性得到了提升。

Since the concept of virtual instrument(VI)was proposed by National Instruments Corporation,many virtual instrument products have been widely used in motor control.LabVIEW is a graphical programming language provided by NI corporation for the development of VI,which greatly facilitates the development of various VI products.In this paper,two methods are used to realize the modelling and simulation of direct current(DC)motor control in LabVIEW,which are the numerical solution method of state equation and the transfer function method.The open-loop starting simulation of the DC motor is realized with the numerical solution method,and the complete speed and current closed loop control system of DC motor is modelled with the transfer function method.Then,two additional closed loop control of back EMF and excitation current are added to realize the flux weakened speed regulation above the base speed,which makes the speed range wider and the system stability improved.