基于MATLAB三相异步电机恒压频比调速仿真

摘 要

随着电力电子器件的产生，异步电机的调速问题得到了很好的解决，调速性能甚至优于直流电机，电力电子器件的产生给异步电机的调速问题带来了福音。

异步电机的调速有多种方法，转速开环恒压频比控制是交流电动机变频调速最基本的一种控制转速方式，在一般的变频调速装置里面都嵌入有这项功能，工作方式为恒压频比的调速方式能满足大多数场合交流电动机调速控制的要求，使用起来也相对方便，是通用变频器的基本模式。但在低压时候需要一定的补偿电压，采用恒压频比控制，在基频以下的调速过程中的转差率会保持不变，电动机的所以会机械特性会相对较硬，电动机有较好的调速性能。

正选脉冲宽度调制三相逆变电路，是一种以三角波做载波的应用冲量等效原理而获得理想交流电源的电路装置，在调制比与载波比一定的条件下，通过调节外加直流电源的大小就可以获得在额定频率下产生额定电压的正选电压波，通过调节正弦波的频率就可以得到理想的电压频率波，而且调节输入正弦波的频率能得到线性的输出电压幅值。MATLAB在电气领域中的运用随处可见，在这里可以运用MATLAB里的Simulink仿真出具体的模型，通过示波器来观察具体的波形，从而进行进一步的分析。

关键词：异步电动机,变频调速，MATLAB 仿真，正弦脉冲宽度调制

Abstract

With the generate of power electronic devices,Asynchronous motor speed control issues have been solved well,Velocity modulation performance even better than the DC motor,Can be said that the generation of the power electronic devices brought the gospel to the asynchronous motor of its speed control.

There are several methods to control the asynchronous of its speed,The open-loop and constant V/F is the basic control way of the AC motor,Generally frequency control devices have this feature , The control way constant of V/F can fit the most occasions to AC motor speed control requirements, and easy to use, and is the model of general-purpose inverters. However, it need a certain amount of compensation voltage, The control way of the constant V/F can keep the slip of the AC motor constant, so the mechanical characteristics of the motor is hard, the motor has good velocity modulation performance.

Sine pulse width modulated three-phase inverter circuit, use the triangular wave to be the carrier and the impulse equivalence principle to obtain the desired AC power circuit way, when the modulation ratio and carrier ratio are constant, by adjusting the applied DC power, the size rate frequency and rated voltage can be selected .We can obtain ideal voltage frequency wave just by adjusting the frequency of the sine wave, and we also can obtain linear output voltage amplitude by adjusting the frequency of the sine wave. The use of MATL