Development Of High Efficiency And High Current Electromagnetic Transmitter Based On AC-AC Topology

Marine controlled source electromagnetic methods (MCSEM) towed the electromagnetic transmitter to the offshore seabed, lauching high-power electromagnetic waves by the transmitter dipole to the seabed, the field source signal back form the electromagnetic receiving equipment and after processing and inversion, we can analyze the seafloor conductivity structure of the media, and it is one of the effective exploration of gas hydrate resources.Marine controlled source electromagnetic transmitter is to an important part of achieving marine controlled-source electromagnetic exploration, development of high-performance, high current electromagnetic transmitter system has a very important significance for deep-sea exploration.For the basic features and research status of marine controlled-source electromagnetic transmitter and research foundation and technical difficulties of highly efficient and large currentelectromagnetic transmitterbased on AC-AC efficiency topology, the paper developed highly efficient and large current electromagnetic transmitter. On the original topology is optimized and improved.This paper analyzes the topologyand working principle of the electromagnetic transmitterbased onAC-AC, according to the topology erected main circuit system of the electromagnetic transmitter according to the topology, and the control scheme of transmitter is studied.According to functional and indicatorsrequirements of the system, the overall structure of electromagnetic transmitter control system has been detailed designed and functional division, presents driven logic and driver software of the H-bridge inverter circuit and dual BUCK coding circuit, and joined the monitoring and protection of voltage, current and temperature.On the basis of the designed control system, we propose an electromagnetic transmitter current loop control algorithm and the main circuit system control strategy.For debugging electromagnetic transmitter system, designedthe power system and power load system, the test showed that the design of the power system can output high voltage and power and the load system complies with little resistance, high power requirements.In addition, also designed electromagnetic transmitter system debugging software, the debugging software is not only able to send control commands, but also real-time display theimportantmonitoring information of the transmitter system.Completed the function module debugging and system-level debugging of the highly efficient and large current electromagnetic transmitter system.Debugging function modules include control board debugging, H-bridge inverter circuit debugging, MOS driver board debugging and gathering information calibration.System-level debugging includesystem open-loop debugging, current loop debugging and analysis and improvement of system debugging problems.The results show that the developed electromagnetic transmitter can output high current signals with satisfactory waveform, verify the effectiveness of highly efficient and large current electromagnetic transmitter based on AC-AC topology.