【摘要】 在瞬变电磁探测领域中,发射电流波形的质量将会直接影响到地质体感应信号的检测。瞬变电磁法理论基于阶跃波电流源激励,为了探测浅层部地质信息,要求脉冲电流关断延时短、上升下降沿线性度高,探测系统动态性能好,但由于发射线圈呈感性,在大电感负载下实现理想的阶跃脉冲是非常困难的。研究改善发射电流脉冲波形前、后沿波形质量的电路拓扑、控制方法,并研究了电磁发射机整流方案。分析了电路的工作原理,讨论了电路参数优化计算,从负载电流上升、下降沿波形的线性度和稳压电容电压波动范围出发,给出了恒流电路中电感值和钳位电容值的最优值选取方法,并通过仿真实验,验证了理论分析的正确性。与已报道电路相比,该电路结构简单,上升、下降沿线性度好,动态性能好。更多还原

【Abstract】 In transient electromagnetic detection field, the quality and performance of excitation source directly affect the detection signal of geological body induction. It needs the pulse current source of the linear reversal edge, the short delay reversal, the constant load current value and the good consistency of positive and negative. In the ideal case, the excitation source is the bipolarity rectangular square-wave, but due to the load of the large inductance coil,it is very difficult to realize the ideal bipolarity rectangular square-wave. The circuit topology and control method were studied to improve the quality of emission current pulse waveform and trailing edge of the waveform, and the electromagnetic transmitter rectified scheme was studied. The working principle of the circuit was analyzed, and the circuit parameter optimization was discussed from linearity of the load current rises and the capacitor voltage.Compared with the reported circuitry, this circuitry has simple structure, good rising and falling linearity and good dynamic performance.更多还原