Long-distance direct-current feed system of underwater vehicle

Abstract

The invention relates to a long-distance direct-current feed system of an underwater vehicle. The system comprises a water surface alternating-current power supply, a water surface high-voltage direct-current cabinet, a high-voltage direct-current feed cable and an underwater power supply converter, wherein the water surface alternating-current power supply is connected with the high-voltage direct-current cabinet, and the high-voltage direct-current cabinet is connected with the underwater power supply converter through the direct-current feed cable; a high-frequency PWM (pulse width modulation) alternating-current chopper, a three-phase three-winding transformer, a three-phase rectifying bridge, a smoothing reactor and a filter capacitor are installed inside the high-voltage direct-current cabinet; the high-frequency PWM alternating-current chopper is connected with the three-phase three-winding transformer, the three-phase three-winding transformer is connected with the three-phase rectifying bridge, and the three-phase rectifying bridge is connected with the smoothing reactor and the filter capacitor. The long-distance direct-current feed system of the underwater vehicle is used for feeding power to the underwater vehicle, and the diameter of a long-distance feed wire is reduced, so that the underwater resistance force of the feed wire is reduced, the size and weight of the power supply converter at the end of the underwater vehicle are reduced so as to reduce the total weight of the underwater vehicle, the influence of distributive impedance parameters of the long-distance feed wire can be eliminated, and the transmission efficiency of the electric power can be improved.

Description

technical field [0001] The invention relates to a long-distance DC feed system for a submarine, which belongs to the technical field of light DC transmission. Background technique [0002] Submersibles (underwater walking robots) have very broad application prospects in deep-water unmanned operations such as marine safety, underwater detonation, and submarine oil exploitation. All the power required by the submersible is fed from the surface base station via long-distance umbilical cables. In order to reduce the resistance of the underwater vehicle, it is required that the diameter of the feeder cable used should be as small as possible, and the volume of the underwater converter should be as small as possible and the weight as light as possible. In order to expand the underwater movement radius of the submersible, the length of the feeder cable used is required to be as large as possible. However, the small wire diameter and long cable length will cause very serious cable...

AI Technical Summary

Problems solved by technology

The increase of distributed inductive reactance further increases the voltage drop of the line, and the reduction of distributed capacitive reactance increases the reactive current of the line. As a result, the active power that can be transmitted to the end of the line is greatly reduced, and the reactive power loss of the cable is greatly increased.

Second, after passing through the step-down transformer at the end, a three-phase bridge rectifier circuit is used, so that the harmonic THD of the current on the umbilical cable can reach 300%-500%, and the peak value of the current can reach more than ten times the fundamental wave, and The lowest order of harmonic current is 5 times frequency, that is, 2kHz, which produces serious skin effect and further aggravates the heating of cables

Third, due to the use of uncontrolled rectification and inverter frequency conversion circuits in the surface base station, the AC harmonics generated seriously pollute the surface AC power supply. to other nearby electrical equipment

Therefore, power transmission technology is a major bottleneck of submersible body technology, which limits the application of submersible body technology to the existing range of low power, shallow water, and offshore

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