针对超磁致伸缩致动器由于大电感线圈的存在而使电流上升时间较长,以致于无法满足快速开启需求的问题,分析了致动器等效电路以计算精确的线圈电流,并设计了较为合理的驱动电压波形。从对致动器阻抗的描述精度出发考察3种等效电路,确定了带并联电阻的等效形式最为合理;分析计算了该种等效形式下方波电流输入时的电流表达式,得到不同频率下致动器电流瞬时响应,并通过实验测试了致动器阻抗以及电流瞬时值以验证等效电路的准确性。最后基于该等效电路,借鉴电磁阀的大电压开启方法,分析了合理的电压形式并提出了参数设计方案,计算结果表明,设计电压能在保证较小超调量的同时有效地降低电流调整时间。
Raising time of the current within the giant magnetostrictive actuator,with a winding inside,is always considerably long for the big inductance of the winding,and then the requirement of quick response could not be satisfied. To solve this problem,equivalent circuit for calculating precise current of the actuator was analyzed and suitable format of the driving voltage was designed. Three kinds of equivalent circuits were considered,and the equivalent form with a parallel-resistance inside was selected as the most effective one for its best description on the impedance of the actuator. The current equation of the best equivalent circuit,under square voltage input,was calculated and then the transient responses under different frequencies were achieved. Experimental impedance of the actuator and transient current within the winding was compared with the calculated results to validate the equivalent circuit. Based on the equivalent form with a parallel-resistance inside,efficient form of the driving voltage,with the high-switching-voltage technology employed,was designed and inside parameters were optimized. The calculated results show that the driving voltage designed reduces the modulating time of the current effectively with little overshoot.