异步电机斩波串级调速方法研究

Research on Chopper Cascade Speed Regulation Method for Asynchronous Motor

针对异步电机低速运行时功率因数低的缺点,在传统串级调速加入了升压斩波环节加以改进,介绍了斩波串级调速电路提高功率因素的原理,得到斩波器占空比与电机转速的关系。论述了系统的机械特性,可知在转速较高的运行状态下,斩波串级调速系统对电机的机械特性影响较小,说明其具有较硬的机械特性。并设计了双闭环无静差调速控制系统,以7.5 kW/380 V异步电机为调速对象进行了仿真,仿真结果表明,双闭环控制系统具有较好的动态性能和稳态抗扰性能。

In view of the shortcoming of low power factor in asynchronous motor running at low speed,the step-up chopper is added in the traditional cascade speed regulation.The principle of improving the power factor of chopper cascade speed circuit is introduced,and the duty cycle of the chopper is obtained.Relationship with motor speed.The mechanical characteristics of the system are discussed.It can be seen that the chopper cascade speed control system has less influence on the mechanical characteristics of the motor under the higher running speed,indicating that it has hard mechanical characteristics.The double closed loop non-stationary speed control system is designed.The 7.5 kW/380 V asynchronous motor is used as the speed control object.The simulation results show that the double closed loop control system has better dynamic performance and steady-state anti-interference performance.