自适应供油压力变化的高速开关阀控制策略研究

Research on Control Algorithm for High-speed on/off Valves that Adaptive to Supply Pressure Changes

针对球阀结构高速开关阀动态特性受供油压力影响大的问题,提出自适应供油压力变化的高速开关阀控制策略,通过计算不同供油压力下的高速开关阀临界启闭电流,结合电流反馈机制,实现多个激励电压源之间的自动切换,最大程度上维持了高速开关阀在变供油压力下的动态特性。理论分析验证了供油压力对高速开关阀的动态特性有较大影响。仿真和试验都达到了控制策略的预期效果,结果表明,与单电压驱动方法相比,自适应供油压力变化的高速开关阀控制策略在5~20 MPa的供油压力变化范围内,能有效减少高速开关阀总启闭时间56.9%~75.8%,扩大可控占空比范围45.9%~240.6%,提高最大工作频率161.0%~637.5%。在动态性能提升的同时,自适应供油压力变化的高速开关阀控制策略将启闭总时长的变化率控制在2.1%以内(变化范围0.2 ms),可控占空比范围的变化率稳定在2.1%以内,最大工作频率的差异系数保持在4.6%以内。

Aiming at the problem that the dynamic characteristic of the sphere structure high speed on/off valve(HSV)is greatly affected by the supply pressure,a control algorithm for HSV that adaptive to supply pressure changes is proposed.Adaptive switching of multi-voltage sources is realized by combining current feedback operation principle with calculating critical switching currents of HSV under different supply pressures,so that the dynamic performance of the HSV under changing supply pressure can be preserved.Theoretical analysis proves that the supply pressure has a great influence on the dynamic characteristic of the HSV.Both simulation and experiment results achieve the expected effects of the presented control strategy.Compared to the single voltage driving method,the results show that when supply pressure changes from 5 MPa to 20 MPa,the presented control algorithm can effectively shorten the total switching time by 56.9%-75.8%,expand the controllable duty cycle range by 45.9%-240.6%,and improve the maximum operation frequency of HSV by 161.0%-637.5%.What’s more,the change ranges of both total switching time and controllable duty ratio can be remained within 2.1%,and the difference coefficient of maximum operation frequency is less than 4.6%.