一种双电压合成信号脉宽调制的低功耗高速电磁铁驱动电路

针对提升电液控制系统动态和稳态性能的需求,提出一种双电压合成信号脉宽调制的低功耗高速电磁铁驱动电路。与常见的双电源切换电路不同,该电路通过单稳态触发器电路、反相输入求和电路、反相比例运算电路合成一个双电压信号,与高频三角波电路比较产生一个双占空比的脉宽调制信号,最后经功率放大级输出,实现初始阶段100%占空比脉宽调制信号使电磁铁线圈电流急速上升驱动衔铁高速运动,运动结束后又以10%占空比实现低功耗保持,避免了双电源切换电路设计的复杂性和实时性问题。基于上述原理,建立高速电磁铁及驱动电路的理论模型,仿真分析电磁铁的动态和稳态性能,并结合原型样机进行实验验证。研究结果表明:与典型恒定电压或恒定占空比控制方式相比,性能明显提高,该驱动电路作用下的电磁铁在2.5mm行程内开启时间为10ms,关闭时间为22ms,稳态功耗为0.3W,可更好地满足低功耗高速电磁铁的驱动要求。

In order to improve the dynamic and steady-state performance of the electrohydraulic control system,a high-speed solenoid drive circuit with low power consumption was presented,which was based on pulse width modulation(PWM)by using dual voltage synthesized method.Unlike common dual power switching circuit,it synthesizes a dual voltage signal by combing a monostable trigger circuit,a reverse input summation circuit and a reverse proportional operation circuit,and then generates a pulse width modulation signal with dual duty ratio compared to a high frequency triangle wave signal,and finally outputs power by the amplifier.As a result,a PWM signal with 100%duty ratio in the initial stage achieves the armature in high speed by rapid current rise of solenoid coil,and the low power consumption is maintained with a 10%duty ratio after the end of the movement.It can avoid the complexity and real-time performance of dual power switching circuit design.Theoretical model of the high-speed solenoid and circuit is hence established,and the simulations regarding the dynamic and steady-state performance were verified by experimental results of the prototype.The results show that the performance of the drive circuit is obviously improved compared to typical constant voltage or constant duty cycle control method.The opening time,closing time,and the steady-state power consumption of solenoid are 10ms,22ms and 0.3W respectively within a stroke of 2.5mm,which better meet the drive requirements of high-speed solenoid with low power consumption.