电磁式自供电在线监测系统的设计与优化

Design and Optimization of Electromagnetic Self-powered Online Monitoring System

电线周围的电磁场能量丰富,可通过设计自供电在线监测系统进行安全检测,但由于能量密度低,取能线圈采集到的能量通常无法直接驱动负载工作。针对这一问题,对磁芯的磁路进行优化和对电源管理电路进行阻抗匹配。通过分析取能线圈磁芯的磁路和实际应用的需要,将其设计为一种U形斜面切口的结构,增大磁芯的有效磁导率。运用串联谐振的匹配电路使取能线圈呈电阻性输出,增加有功功率输出。与未进行匹配电路相比较,最大有功功率输出增加了2.6倍,充电速度可达4倍。经实验验证,该采集器可以驱动在线监测系统正常工作,且传感器节点的零数据丢失传输距离达50m。

There is a lot of magnetic field energy around the wires. Safety detection can be achieved by designing a self-powered online monitoring system, but due to the low energy density of the electromagnetic field, the energy collected by the energy-carrying coil is usually unable to directly drive the load. In order to solve this problem, we optimize the magnetic circuit of the magnetic core and perform impedance matching on the power management circuit. By analyzing the magnetic circuit of the energy-obtaining coil core and the needs of application, it is designed as a U-shaped beveled slit structure to increase the effective magnetic permeability of the core. We use a series resonant matching circuit to make the energy-obtaining coils resistive and increase the active power output. Compared with the unmatched circuit, the maximum active power output is increased by 2.6 times and the charging speed is up to 4 times. The results show that the energy harvester can drive the online monitoring system to work normally, and the zero-data loss transmission distance of the sensor node is up to 50 m.