变电流反馈的串励直流电动机调压调速控制方法

Variable voltage control strategy with alterable current feedback for the series-excited motor system

针对串励直流电动机在低压运行时易堵转和在高压下重载运行时会严重过载的缺陷,提出一种变电流反馈的串励直流电动机调压调速控制方法。在建立系统数学模型并将其线性化的基础上,分析给出确保系统稳定的设计约束条件。该控制方法的应用表明,串励电动机调速系统的低压驱动能力得到明显提高,并具备了过载保护,且正常运行时系统保持有串励直流电动机的软机械特性。

Due to the soft mechanical characteristic of series-excited motor’ s open-loop-adjusting driving system, the performance of the motor has some defects, such as insufficient driving force when working in low excited voltge and low-speed conditions, serious overcurrent when working in high excited voltge, o-verload and low-speed conditions. Addressing these problems, this paper proposed a variable voltage con-trol strategy with alterable current feedback for the series-excited motor. The linearized mathematical model with alterable current feedback for the series-excited motor’ s speed-adjusting system is analyzed, and the conditions and methods for designing the alterable current feedback system to ensure the system to be operated stablely are clarified. Taking the series-excited motor system using the proposed control strat-egy for household sewing machine as an example, the driving capacity at low is improved significantly, the winding current is limited when working in overload condition and the series-excited motor’ s soft me-chanical characteristic is retained under normal operation.