直流脉宽调速系统电流脉动规律分析  

The Laws of the Current Ripple in DC Motor PWM Speed Regulating System

作　　者：柏艳红[1] 李虹[1] 孙志毅[1] 

机构地区：[1]太原科技大学自动化系,山西太原030024

出　　处：《电气电子教学学报》2010年第2期35-38,103,共5页Journal of Electrical and Electronic Education

基　　金：山西省高校科技研究开发项目(2007141)

摘　　要：本文在研究直流脉宽调速系统的电流脉动规律中,推导了PWM变换器处于不同工作状态时电流动态过程的统一表达式;分析了电动机在不同运行状态下的电流波形,给出了电动运行状态和降速过程的转速、电枢电流和电压的响应曲线;得出了无论电动机处于电动还是制动状态,在一个开关周期内,电枢电压在电源电压和零电压间切换,电流动态过程包括电流上升和下降两段,都遵循所推导出的电流表达式。笔者通过仿真,研究了PWM信号的占空比、开关周期和电磁时间常数等参数对电流脉动幅值的影响。In this paper, the laws of the current ripple in DC motor PWM speed regulating system are studied. An expression of the current dynamics which can be used in different working states of the DC-DC PWM converter is deduced. The current waveforms are analyzed under different operating conditions of the motor. And the dynamic response curves of speed, armature current and voltage are provided in motoring state and in speed decreasing process. The conclusion that the current dynamic processes during a switching period are consistent both in motoring mode and in braking mode is drawn. The armature voltage is switched between the source voltage and zero voltage, and the responding current dynamic processes include ascending stage and descending stage, which follow the proposed current expression. The amplitude of the current ripple is influenced by electromagnetic time constant, switching period and duty of PWM signal, which is researched by simulations.

关 键 词：直流脉宽调速系统 PWM变换器 电流脉动 仿真 

分 类 号：TM3[电气工程—电机]