智能接触器准临界电流搜索自起动控制

庄杰榕 许志红

关键词：数字闭环;下降拐点;自起动;准临界电流;模糊观测

DOI：10.15938/j.emc.2019.06.000

中图分类号文献标志码：A 文章编号：1007 -449X（2019）06 -0000 -00

Abstract：A selfstarting control strategy with quasicritical current for intelligent contactor was proposed. The forced down phenomenon of coil current was analyzed and the constraint condition for current closedloop was inferred. Based on these， the universal feedback signal of movement of contacts was established. Thus the quasicritical starting current was obtained when turning point occurred. By fuzzy observation， the starting current for contactor of different capacity was provided for the first time. A digital closedloop control method with opposite polarity voltage was designed. The high response online current search was used to approach critical starting current under the current working condition， in order to realize selfstarting process control with coordination between attraction and counterforce. The proposed control strategy which is insensitive of contactor parameters change and voltage fluctuation， can adaptively search for the quasicritical current to suppress the contact bounce. At the same time， it has the advantages of starting block fault alarm， coil overcurrent protection and so on. The effectiveness of the control strategy is verified by the related simulations and experiments.

Keywords：digital closedloop;dropping turning;selfstarting;quasicritical starting;current fuzzy observation

0 引 言

高性能的智能接觸器在新能源并网、电动汽车等领域中承担着可靠通断电路的控制任务，受到国内外学者的广泛认可及研究[1-4]。文献[5-7]分别采取实验归纳及数值仿真方法，分析交流接触器最佳的合闸相角，设计选相控制方案，一定程度上抑制了触头弹跳;文献[8-11]将电磁系统的励磁方式由交流变换为直流，实现无分磁环的本体结构，显著减小磁滞涡流损耗，开关可节能无声运行;文献[12-16]引入电压或电流反馈，快速调节电磁机构励磁状态，解决开环控制缺陷，实现电磁系统交直流通用、宽电压运行，触头系统弹跳抑制等;文献[17-19]分别基于电磁机构的磁路模型、电路模型及动态仿真分析，实现永磁接触器位移分段PWM控制;文献[20]将模型预测融入接触器运动过程仿真，改变电压施加时间进而调节励磁电流，显著减小因开关投切弹跳引起的系统暂态涌流。总结以上文献，励磁电流曲线是直接影响接触器吸合过程吸反力配合的重要参数，间接关系到触头弹跳和动作稳定性。文献中大多通过离线方法获取这一关键控制参量，离线方法可分为机理建模和试验，得到的控制规律具有一定效果。然而，离线参量始终指导接触器在线时变的运行状态，局限性大：接触器规格种类繁多，反力等特性不同;运行工况日益复杂，以安装于海上……