采煤机牵引电机磁极开关组合控制研究

为满足煤矿开采生产需求,提出了采煤机牵引电机磁极开关组合控制方法。通过分析采煤机牵引电机运行原理,将TMS320F2811型数字信号处理芯片作为核心硬件,设计由采样模块、磁极开关组合控制器等构成的采煤机牵引电机磁极开关组合控制结构,采样模块采集采煤机牵引电机功率变换器的电流、电压值后,将其传输到磁极开关组合控制器中,该控制器输出脉冲触发,经过控制驱动软件驱动CPLD逻辑处理器件控制驱动程序驱动电路后,控制磁极开关组合开启或关闭,实现采煤机牵引电机磁极开关组合控制。其中,控制驱动程序使用Linux嵌入式操作平台提供的交叉编译器编写。实验结果表明,该方法可有效控制采煤机牵引电机磁极开关开启或闭合,其控制采煤机牵引电机磁极开关组合时,控制输出曲线与期望输出曲线较为吻合,且控制磁极开关组合后,采煤机牵引电机电流畸变数值较小,具备较为显著的应用效果。

采煤机牵引电机磁极开关组合结构的研发及应用

磁极开关组合结构设计,是在采煤机牵引电机原有的接线盒电机输出轴端安装磁极开关,用以精确测量电机的转动圈数,进一步计算出采煤机销轨轮转动的圈数,从而精确地计算出采煤机在工作面移动的距离。提高了采煤机运行位置的检测精度,为提升采煤工作面的智能化检测和控制水平,实现采煤机的智能监测监控打下坚实的基础。

Realization of Spin Switch in a Triple-Terminal Double-Quantum-Dot Structure

Electron transport through a triple-terminal double-quantum-dot structure is theoretically studied. By adjusting the chemical potential in leads, two channels in this system are created, and in the presence of magnetic flux the conductances for the two channels present remarkable difference from each other. When the quantum dots are made of ferromagnetic materials, the levels of quantum dots are spin dependent, then spin polarization comes about in the two channels. Furthermore, in some regions spin polarization in the different channels are opposite. We consider that this model can be a device prototype for spin filtering and spin separation.