【摘要】 设计了一种用于三维感应测井仪的功率放大器。由现场可编程门阵列(FPGA)控制发射频率的选择并输出发射信号,采用D类功率放大器,有效降低系统功耗,提高效率,用并联谐振回路实现选频功能;针对功放电路在高温下发射电流随温度上升而增加的情况,采用脉冲宽度调制(PWM)方式自动调节功率放大器的端电压,稳定发射电流。实验结果表明,常温下放大器效率达到76%,谐波抑制比超过40dB;150℃温度下工作1h,发射电流稳定在1A,系统稳定性明显增加。该设计已成功应用于三维感应测井仪实验样机中。更多还原

【Abstract】 A novel power amplifier is designed for 3D induction well-logging tool.The FPGA decides the choose of emission frequency and when to output.The class-D power amplifier is used to reduce the system consumption and improve the efficiency.The parallel resonance circuit is to achieve the function of frequency selection.The PWM is used to adjust the voltage of the class-D power amplifier,which can stabilize the emission current in high temperature.The experimental results show that the efficiency of the power amplifier reaches 76%,the THD ratio exceed 40 dB.After working at a temperature of 150℃for one hour,the emission current still is the 1A.The stability of the system is increased significantly.This power amplifier has been successfully used for laboratory prototype of the 3D induction logging tool.更多还原