一种基于NIOS的双极性相控高压脉冲信号源设计

摘要

通过分析相控声波测井技术对高压激励信号源的需求,提出了一种基于NIOS的双极性相控高压脉冲信号源设计方案.选用具备NIOS处理器的FPGA芯片作为控制器,提高了系统逻辑处理的灵活性,降低了外围电路的复杂程度.利用高压储能电容作为储能元件,结合电阻分压电路和AD采样芯片构成闭环幅度控制回路,保证了脉冲幅度的准确性.利用浮地驱动芯片和高速MOSFET构成脉冲驱动及转换电路,实现了脉冲信号的双极性转换及功率放大.利用最小二乘法对输出脉冲进行幅度和脉宽修正,提高了脉冲幅度和宽度的精度.实验结果表明:该脉冲信号源可产生幅度范围在-300 ～ 300 V,脉冲宽度范围在200 ns～10 ms的双极性高压方波脉冲,且脉冲幅度、脉冲宽度、发射频率、通道延时等参数均可灵活调节,为声波相控测井技术的应用提供了必要的硬件支持.%Based on the analysis of the requirement of the high voltage signal source,a design scheme of bipolar phasecontrolled high voltage pulse signal source based on NIOS is proposed.The FPGA chip with NIOS processor is used as the controller,it improves the flexibility of the system logic processing and reduces the complexity of the peripheral circuit.The high voltage energy storage capacitor is used as the energy storage element.With the resistance voltage dividing circuit and a kind of AD sampling chip,a closed loop amplitude control loop is formed.By using the floating driving chip and the high speed MOSFET,the pulse drive and conversion circuit are formed,and the bipolar conversion and power amplification of the pulse signal are realized.By using the least square method,the amplitude and pulse width of the output pulse are corrected,and the precision of the pulse amplitude and width is increased.Experimental results show that the pulse signal source amplitude range is flexible in the-300-300 V,bipolar pulse width in 200 ns-10 ms.Pulse amplitude,pulse width,transmission frequency,channel delay and other parameters can be adjusted flexibly.It provides the necessary hardware support for the application of sonic logging technology.