直流电机实验工况自动控制系统的研制

针对机车辅助直流电机测试中电机运行工况的控制,本文采用晶闸管相控整流方式对电机进行调压调速。调速主电路由变压器隔离降压,三相桥式全控整流和平波电抗器滤波组成。控制电路由单片机产生数字脉冲串对晶闸管触发移相,通过改变控制角来改变输出电压的大小;采用锁相环技术使触发脉冲与电源电压之间保持频率和相位的协调关系;并且引入了电压负反馈,由单片机程序作PID运算来计算控制角,提高调速精度和机械特性。

The Development about Auto-controlling the Experimental Status of Locomotive Auxiliary Direct Current Motor

To auto-control motor's running status during testing locomotive auxiliary DC motor, the Silicon controlled rectifier was used in this paper to adjust voltage-velocity regulation. The main velocity regulation circuit was composed of the transformer, the three-phase bridge controlled circuit and the flat wave reactor. In the control circuit, the digital pulse strings produced by the MCU trigger the thyristors to shift phases, through changing the control angle, the voltage output could be changed. The phase-lock link technology was adopted to keep in-phase between the trigger pulse and the supply voltage. Simultaneously, the voltage negative feedback was used, and the programs of MCU operating PID computed the control angle to enhance the precision of velocity regulation and the rigidity of physical characteristics.