本文建立了一个基于直接转矩控制的异步电机变频调速系统。系统采用了两个滞环控制器,分别比较定子给定磁链与实际磁链、给定转矩与实际转矩的差值,然后根据这两个差值查询逆变器电压矢量开关表得到施加在异步电动机定子绕组上的电压矢量,然后通过脉冲宽度调制(Pulse Width Modulation,PWM)逆变器控制异步电动机。(An asynchronous motor variable frequency speed regulation system based on direct torque control is established in this paper. The system uses two hysteresis controllers to compare the difference between the stator flux and the actual magnetic chain, the given torque and the actual torque respectively. Then the voltage vector applied to the stator winding of the asynchronous motor is obtained by the two difference values, and then the pulse width modulation (Pulse Width Modulation) is used. PWM) the inverter controls the asynchronous motor. According to the characteristics of the asynchronous motor direct torque control variable frequency speed control system driven by the PWM inverter, the Matlab\Simulink is used to model and simulate the variable frequency speed control system of asynchronous motor)