J Shanghai Jiaotong Univ Sci ›› 2021, Vol. 26 ›› Issue (6): 828-839.doi: 10.1007/s12204-021-2286-4

• Automation, Image Processing • Previous Articles     Next Articles

Snubber Circuit for Marine Controlled-Source Electromagnetic Transmitter

SONG Hongxi∗ (宋红喜), ZENG Yijin (曾义金), ZHANG Wei (张卫)   

  1. (Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China)
  • Received:2019-12-26 Online:2021-11-28 Published:2021-12-01

Abstract: A high-power marine controlled-source electromagnetic transmitter (HP-MCSET) transmits a highfrequencyconversion 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). Thereis a high voltage peak in the LB when the insulated gate bipolar transistor (IGBT) is turned on and off. In somecases, the voltage stress of the IGBT can be exceeded, which may cause IGBT damage. Because the rise of thecurrent steepness is relatively low and the output voltage has a voltage peak in the LB, a snubber circuit is addedto the IGBT to suppress the voltage peak to improve the output current and voltage waveform. The suppressionof the voltage peaks is analyzed and compared for several groups of snubber circuits. To meet the performancerequirements of the MCSET, the optimal snubber circuit is selected to effectively suppress the voltage peaks atan output current of 1 kA. This method is verified by using a 70 kW MCSET and the experimental waveforms areprovided. The simulation of the inductance obstruction load in seawater is necessary to determine the conditionsfor actual marine environment experiments.

Key words: launch bridge (LB), switching power supply, snubber circuit, voltage peak, marine controlled-sourceelectromagnetic transmitter (MCSET)

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