一种开关驱动的电涡流式位移传感器的原理与实验研究.pdfVIP

学兔兔 第31卷 第11期 仪 器 仪 表 学 报 Vo1．31 No．11 2010年11月 Chinese Journal of Scientific Instrument NOV．2010 一 种开关驱动的电涡流式位移传感器的 原理与实验研究 钟建朋，李黎川 (西安交通大学电气工程学院 西安 710049) 摘 要：从能量损耗角度出发，对一种开关电路驱动的电涡流位移传感器的工作原理进行了分析。该传感器利用气隙与工作 电流问的对应关系实现对目标位移的检测，且仅需一次低通滤波即可完成信号调理，系统结构简单。作者以铁、铝和无磁不锈 钢作为被测目标在不同开关频率下进行了实验研究，并对实验结果进行了分析。结果表明：对3种被测目标，随着频率的变化， 系统灵敏度经历了相似的变化过程，且在谐振频率附近，灵敏度达到负向最大值；在0．5与1．5倍谐振频率的两个频率附近，系 统灵敏度达到两个正向极大值；在谐振频率附近， 被测目标为铁时，系统灵敏度最大，而目标为铝时次之。 关键词：电涡流位移传感器；开关驱动；能量损耗；谐振频率 中图分类号：TP212．13 文献标识码：A 国家标准学科分类代码：460．4020，470．4017 Fundamental and experimental research on a switch-driven eddy—current displacement sensor Zhong Jianpeng，Li Lichuan (School ofElectrical Engineering，Xian Jiaotong University，Xian 710049，China) Abstract：The fundamental of a switch—driven eddy—current displacement sensor is analyzed based on the eddy cur- rent power loss．The sensor achieves target displacement detection based on the relationship between the gas gap and the working current；and only one low pass filtering is needed for the signal conditioning．A series of experiments were carried out at different switching frequencies with iron，aluminum and nonmagnetic stainless steel as the tar- gets；and the experiment data were analyzed．Analysis results show that as the switching frequency changes the de— tection sensitivity experiences a similar variation process for different targets；and the sensitivity reaches a negative maximal value around the resonance~equency，the sensitivity reaches two positive maximal values at approximately half and 1．5 times the resonance~equency；the sensitivity for iron has its largest value aro