A Novel Circuit of Marine Controlled-source Electromagnetic Transmitter

Abstract

The marine electromagnetic transmitter sends high-power variable-frequency electromagnetic waves to acquire seabed structure and distribution law of mineral resources. The traditional transmitter has some shortcomings, such as small power, low efficiency, and poor load adaptability. In this article, a novel transmitter circuit composed of zero voltage zero current switching (ZVZCS) controlled-source circuit is proposed, which overcomes the limitations of a zero-voltage switching one, such as high freewheeling energy, duty ratio loss, and limited zero-voltage switching load range for the lagging-leg switches. Current in primary winding during the freewheeling period is reduced to zero by using a blocking capacitor and a saturable reactor, realizing zero-current switching turn-on for leading-leg switches, as well as zero-current switching for lagging-leg switches. Finally, the proposed circuit is verified by a 200-A marine transmitter.