High-Frequency Broadband Resonance Compensator for the Controlled-Sourse Audio-frequency Magnetotelluric Transmitting system

Controlled-source audio-frequency magnetotellurics ( CSAMT ) is an important means to detect underground electrical anomalies, and the transmitter is its core component. However, due to the effect of transmitting cable, the transmitter cannot generate a large current in high-frequency bands (≥2kHz), which will make it impossible to obtain high signal-to-noise ratio (SNR) data in high-frequency bands using the CSAMT method, and ultimately affect the shallow detection accuracy. To solve the above problems, this paper analyzes the transmitting loop when using the CSAMT method, a new High-Frequency Broadband Resonance Compensator (HBRC) by adding fixed capacitors with a magnetic-controlled reactor (MCR) is proposed in this article to the transmitting circuit to increase the current energy at each frequency point at a higher power. Furthermore, a broadband adaptive control strategy for HBRC is proposed. Finally, the system is tested under 100m and 1000m cable conditions. The results show that the detection main frequency energy can be effectively enhanced by 10.00%-295.27%, Power Utilization Factor Power(PUF) can be effectively enhanced by 1.96%- 73.26%, efficiency can be enhanced by 1.01%-57.75%, active power increases 51.43W-440.32W in the 2.56–9.6 kHz transmission band using the proposed technique. Compared with conventional schemes, the proposed HBRC allows adaptive resonance compensation at a higher power.