A high-power marine controlled-source electromagnetic transmitter(HP-MCSET)transmits a highfrequency conversion current on the sea floor.Some problems exist when the direct-current to alternating-current(DC-AC)launch ...A high-power marine controlled-source electromagnetic transmitter(HP-MCSET)transmits a highfrequency conversion current on the sea floor.Some problems exist when the direct-current to alternating-current(DC-AC)launch bridge(LB)is used in the marine controlled-source electromagnetic transmitter(MCSET).There is a high voltage peak in the LB when the insulated gate bipolar transistor(IGBT)is turned on and off.In some cases,the voltage stress of the IGBT can be exceeded,which may cause IGBT damage.Because the rise of the current steepness is relatively low and the output voltage has a voltage peak in the LB,a snubber circuit is added to the IGBT to suppress the voltage peak to improve the output current and voltage waveform.The suppression of the voltage peaks is analyzed and compared for several groups of snubber circuits.To meet the performance requirements of the MCSET,the optimal snubber circuit is selected to effectively suppress the voltage peaks at an output current of 1 kA.This method is verified by using a 70 kW MCSET and the experimental waveforms are provided.The simulation of the inductance obstruction load in seawater is necessary to determine the conditions for actual marine environment experiments.展开更多
针对海洋电磁勘探的低频、微弱电场信号采集中电极与放大采集电路的耦合问题,提出了一种支持直流耦合的电极极差自动补偿放大采集电路设计方法,给出了系统设计实现,详细介绍了电极极差自动补偿放大采集电路和自动补偿控制算法。测试结...针对海洋电磁勘探的低频、微弱电场信号采集中电极与放大采集电路的耦合问题,提出了一种支持直流耦合的电极极差自动补偿放大采集电路设计方法,给出了系统设计实现,详细介绍了电极极差自动补偿放大采集电路和自动补偿控制算法。测试结果表明,所设计的电极极差自动补偿方法可将0.1～0.7 m V的电极极差自动补偿至0.043～0.074 m V,均控制在0.1 m V以内,满足了海洋电场采集直流耦合的需求,降低了电场采集电路对不极化Ag/Ag Cl电极的极差设计要求,可有效应用于海洋低频电场信号采集。展开更多
基金the National Science and Technology Major Project(No.2016ZX05021-002)the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences(No.XDB06030204)。
文摘A high-power marine controlled-source electromagnetic transmitter(HP-MCSET)transmits a highfrequency conversion current on the sea floor.Some problems exist when the direct-current to alternating-current(DC-AC)launch bridge(LB)is used in the marine controlled-source electromagnetic transmitter(MCSET).There is a high voltage peak in the LB when the insulated gate bipolar transistor(IGBT)is turned on and off.In some cases,the voltage stress of the IGBT can be exceeded,which may cause IGBT damage.Because the rise of the current steepness is relatively low and the output voltage has a voltage peak in the LB,a snubber circuit is added to the IGBT to suppress the voltage peak to improve the output current and voltage waveform.The suppression of the voltage peaks is analyzed and compared for several groups of snubber circuits.To meet the performance requirements of the MCSET,the optimal snubber circuit is selected to effectively suppress the voltage peaks at an output current of 1 kA.This method is verified by using a 70 kW MCSET and the experimental waveforms are provided.The simulation of the inductance obstruction load in seawater is necessary to determine the conditions for actual marine environment experiments.
文摘针对海洋电磁勘探的低频、微弱电场信号采集中电极与放大采集电路的耦合问题,提出了一种支持直流耦合的电极极差自动补偿放大采集电路设计方法,给出了系统设计实现,详细介绍了电极极差自动补偿放大采集电路和自动补偿控制算法。测试结果表明,所设计的电极极差自动补偿方法可将0.1～0.7 m V的电极极差自动补偿至0.043～0.074 m V,均控制在0.1 m V以内,满足了海洋电场采集直流耦合的需求,降低了电场采集电路对不极化Ag/Ag Cl电极的极差设计要求,可有效应用于海洋低频电场信号采集。
