Wu Zhongping, Zhang Kuiyuan, Zhang Rongbo, Lin Zucan, Wang Meng, Wang Yongqing, Zhang Qisheng
School of Geophysics and Information Technology, China University of Geosciences (Beijing), Beijing 100083, China.
Key Laboratory of Intraplate Volcanoes and Earthquakes, China University of Geosciences (Beijing), Beijing 100083, China.
Sensors (Basel). 2025 Jul 4;25(13):4183. doi: 10.3390/s25134183.
This paper presents a compact, high-efficiency electromagnetic transmitter for Controlled-source Audio-frequency Magnetotelluric (CSAMT) applications, operating in the 10-100 kHz range. A novel bipolar square-wave inverter topology is proposed, which directly modulates the transformer's secondary-side AC output, eliminating conventional rectification and filtering stages. This design reduces system losses (simulated efficiency > 90%) and achieves an approximately 40% reduction in both volume and weight. The power stage uses a full-bridge bipolar inverter topology with SiC-MOSFETs, combined with a high-frequency transformer for voltage gain. Simulation, laboratory testing, and EMI evaluation confirm stable square-wave generation and full compliance with EN55032 Class A standards. Field validation with a CSAMT receiver demonstrates effective signal transmission and high-resolution subsurface imaging, thereby improving the efficiency and portability of urban geophysical exploration.
本文提出了一种用于可控源音频大地电磁（CSAMT）应用的紧凑型高效电磁发射器，工作在10 - 100kHz范围内。提出了一种新颖的双极方波逆变器拓扑结构，该结构直接调制变压器的次级侧交流输出，省去了传统的整流和滤波阶段。这种设计降低了系统损耗（模拟效率>90%），并使体积和重量都减少了约40%。功率级采用带有碳化硅金属氧化物半导体场效应晶体管（SiC-MOSFETs）的全桥双极逆变器拓扑结构，并结合高频变压器以实现电压增益。仿真、实验室测试和电磁干扰（EMI）评估证实了稳定的方波生成，并且完全符合EN55032 A类标准。使用CSAMT接收器进行的现场验证表明信号传输有效且地下成像具有高分辨率，从而提高了城市地球物理勘探的效率和便携性。
