PWM 放大器在直流伺服控制系统中的应用

使用直流伺服控制系统来实现位置或转速控制时,通常使用的线性放大器由于功耗大、效率低,性能不理想.本文提出使用脉宽调制放大器能够克服这一难题,特别是在低速、大转矩系统中。本文详细分析了脉宽调制放大器的三种工作状态,并分析了脉宽调制放大器驱动下电动机的功耗问题,得到这种驱动方式是节能、经济、合理的结论,因而是可行的。本文并提出了脉宽调制放大器的开关频率选择原则,可供使用中作为理论指导。

THE APPLICATION OF THE AMPLIFIER OF PULSE-WIDTHE MODULATION IN THE D.C.SERVOCONTROL SYSTEM

When a D C servocontrol system is applied to control the position and the rotational speed,its function is not ideal for its high power dissoipation and low efficiency,which are caused generally by us-ing the linear amplifier.In this paper,it is pointed that making use of an amplifier of pulse-width modula-tion can solve the above problem,especially in the system with the low speed and the high torque.Throughanalysing toward three working states of the amplifier mentioned above in detail and examining the powerdissipation of the motor driven by the amplifier,it is found that this driving method is of energyconserving,high efficiency and rationality.Besides,the principle,as the theoretical guidance in applica-tion,for selecting the on-off frequency of the switch,is provided.