Double-fed asynchronous generator variable-speed constant-frequency type ocean current power-generating system

The utility model discloses a double-fed asynchronous generator variable-speed constant-frequency type ocean current power-generating system which is in grid connection with a three-phase network. The power-generating system comprises a hydroturbine, a bed frame, a main shaft, a step-up gearbox, a double-fed asynchronous generator, an excitation current transformer and an airtight cabin, wherein the hydroturbine is mounted on the bed frame; the main shaft is connected among the hydroturbine, the step-up gearbox and the double-fed asynchronous generator; the excitation current transformer comprises a generator-side current transformer unit and a network-side current transformer unit; a direct current capacitor is further in parallel connection between the generator-side current transformer unit and the network-side current transformer unit; both the stator and the rotor of the double-fed asynchronous generator are in winding type structures, wherein the stator is directly connected with the three-phase network, the rotor is connected with the generator-side current transformer unit, and the network-side current transformer unit is connected with the three-phase network; and except for the hydroturbine and the bed frame, all of the other equipment are arranged in the airtight cabin. The power-generating system can be used for generating electrical energy in a range with wide seawater flow rates and realizing grid connection, thus the double-fed asynchronous generator variable-speed constant-frequency type ocean current power-generating system disclosed by the utility model is suitable for application on a large scale in projects.