Research On High-power Automatic Inductance Control System

The controlled source audio-frequency magnetotellurics method(CSAMT)is widely used in the exploration of the deep mineral resources and geological structure,et al,which plays an important role in the earth science research and the national economy construction.However,It is difficult to transmit the high-frequency large current in the inductive controlled source electromagnetic survey under the condition of long electric dipole,resulting in the attenuation of the high-frequency artificial source signal before it has spread to the effective detection area.This design is based on the general project of the National Natural Science Foundation of China(NSFC)" Research on high-frequency large current transmission of CSAMT electric dipoles based on adaptive impedance matching technology".Based on the resonance principle,a system for adaptive impedance matching by controlling high power automatic inductance and resonant capacitance has been developed,to solve the problem of low current during high frequency transmission.The high-power automatic inductance control system described in this article is divided according to its functional modules.The hardware part mainly introduces the function and schematic design of modules,such as impedance matching part,status and frequency acquisition unit,GPS module,data storage module,main control part,power conversion unit,ink screen display module,PCB design,mechanical design and other modules.The software part includes the embedded program running in the main chip STM32 based on C language and the host computer software written by C# language.The main functions of the embedded program include collecting,storing,processing and transferring status information,such as voltage,current,frequency of the transmission circuit and temperature of key components in the device by using in-chip resources and peripherals.Based on the transmission frequency and the result of data processing,the control system can adjust the stepping motor to change the inductance value and control the relay selection under the two working modes of adaptive matching or intelligent output,and let the inductance and capacitance in the transmission circuit are in series or parallel to reach the resonance state.To maximize the current of the transmitting circuit.And controlling the ink screen display module to realize the interface display.The upper computer software is connected with the equipment through the serial port,to realize the monitoring and control of the running state of the equipment.Finally,the paper also introduces the indoor testing of the high-power inductive automatic control system.The contents of the indoor test mainly includes the test of the automatic inductor to test the high frequency emission of the transmission circuit,which consisting of an automatic inductor,a capacitor and a large load.The overall test of the control system,to verify verifies the functions of the acquisition,storage,data processing,transmission and human-machine interface display of the hardware circuit of the control system.The test results can show that the high-power automatic inductance control system formed on the basis of this research results,which has a certain improvement effect on the high-frequency large-current emission.The test results can show that the high-power automatic inductance control system formed on the basis of this research.It has a certain effect in promoting high-frequency highcurrent emission.Its operation is simple and stable.The high-power automatic inductance control system can help solve the inductance control problem of the adaptive impedance matching system,and become a foundation for the final solution to the problem of high-frequency large current emission.