基于高性能的微机电系统(MEMS)敏感结构芯片研制了一种新型带电作业电场测量预警系统,通过实时检测电场大小,当超出电场安全阈值发出预警信号,提醒作业人员采取相应的安全措施。基于相敏检测原理,设计了一种可抑制背景噪声的快速模拟解调电路,解决了数字信号处理精度低、响应慢等不足;基于ARM微控制器设计了信号采集和无线发射模块,并通过Lab VIEW虚拟仪器实现上位机显示;采用多探头三维布点方式,有效降低了人体晃动带来的干扰;10 k V输电线路模拟实验和ANSYS仿真表明:实验与仿真结果具有良好的一致性,系统具有较高测量精度,安全距离预警误差小于4.17 cm。
A novel electric field measurement safety warning system of live working based on micro-electromechanical system(MEMS) sensitive structure chip is developed. The system can give out warning signal once the surrounding electric field value of a live working operator exceed the threshold. Based on phase sensitive detection principle,an analog demodulation circuit which can restrain background noise is designed. It achieves a faster response and gets a higher precision than digital processing circuit. A module of signal acquistion and wireless transmission is designed based on ARM microcontroller. Moreover, using LabVIEW to display received data on upper PC. To reduce the impact caused by body sway, three-dimension measurement method is taken. Experimental result under 10 kV lines has a good consistency with simulation result of ANSYS, and the early-warning error of safe distance is less than 4.17 cm.