Research on fast current turn-off technology of long wire transmitter on ground
Transmitter is the key equipment for electromagnetic exploration of ground artificial source.Under the same transmitting current condition,the larger the pole distance and the higher the signal-to-noise ratio,the better the detection effect.The long wire required for large pole distance has strong inductance(about 3 mH inductance of the 1 km wire).The current turn-off time of the 3 mH inductor is about 103.95 μs under the condition of 1000 V transmitting voltage and 50 A transmitting current.For electromagnetic exploration in the time domain,the signal-to-noise ratio of the observed signal,which is inversely proportional to the logarithm of the turn-off time,improved by 10 dB with the turn-off time decreases 10 times.In this paper,by adding a fast turn-off unit to the transmitting loop and introducing an auxiliary turn-off voltage to form a current high-voltage release loop,the turn-off time under the condition of 1 km long wire is expected to be less than 10 μs,and the signal-to-noise ratio of observed data is increased by more than 10 dB,which has important theoretical significance and engineering value.
Electromagnetic exploration transmitterLarge pole distanceLong wireParasitic inductanceFast current turn-off
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维普
