基于感性负载的瞬变电磁发射波形控制技术

Transmitting waveform control technology for transient electromagnetic method based on inductive load

提出了基于感性负载的瞬变电磁发射波形控制技术,系统以数字逻辑控制器为核心控制单元从时间上精密控制发射时序。采用恒压钳位技术对阻尼吸收电路进行了研究。提出一种新颖的关断时间测量技术,测量准确简单,同时设计了一种特殊的RCD缓冲电路。野外实验结果表明:系统所发射电流波形经过高精度控制关断时间短、下降沿线性度高、关断后无反向过冲及振荡、关断时间测量准确,电流峰值可调。

In the Transient Electromagnetic（TEM）transmitting systems,which are used in narrow places such as coal mine and tunnel,usually multi-turn coils are used.For such a big inductive load,ideal pulse current waveform is the goal for TEM transmitting system.A TEM transmitting waveform control strategy is proposed based on inductive load.Digital logic controller is used to control the transmitting timing sequence precisely.The voltage stabilized clamping circuit is adopted to study the damping resistance circuit.A novel turn-off time measurement technology is proposed and a special RCD snubber circuit is designed to improve the transmitting waveform.Field experimental results show that the transmitting current waveform has the characteristics of short turnoff time,high current falling-edge linearity,without overshoot anf oscillation,and accurate turn-off time measurement.