Low voltage crossing double-fed blower fan, and low voltage crossing method of the same

Abstract

The invention discloses a low voltage crossing double-fed blower fan, and a low voltage crossing method of the same. The low voltage crossing double-fed blower fan includes a motor body, a three phase transformer (5), a first current transformer (1), a chopper (2), an energy storage module (3) and a current transformer set, wherein when detecting that the voltage of a grid connection point drops, an output voltage reference signal of the first current transformer can be obtained through processing of a grid voltage signal; and then the reference signal passes the voltage outer ring controlled by PI and the current inner ring controlled by an internal model, so that a control signal of the first current transformer is obtained and control of the output voltage of the first current transformer can be realized. The low voltage crossing double-fed blower fan solves the problem that when the grid voltage drops deeply, the double-fed blower fan cannot realize low voltage crossing, can effectively control the a double-fed blower fan stator side current transformer, a rotor side current transformer and a direct current capacitor overvoltage during the grid malfunctioning period, and can improve the low voltage crossing capability of the double-fed blower fan.

Description

technical field [0001] The invention belongs to the technical field of low-voltage ride-through of double-fed wind turbines, and more specifically relates to a low-voltage ride-through double-fed wind turbine and a low-voltage ride-through method thereof. Background technique [0002] In recent years, the rapid development of renewable energy power generation, especially wind power, has brought us cleaner power, but also brought challenges to the grid. For wind turbines, especially double-fed asynchronous wind turbines (Double-Fed Induction Generator, DFIG), when a low-voltage fault occurs in the grid, back-to-back converters will generate overvoltage and overcurrent, which will cause the wind turbine to go off-grid or even be damaged Converter. [0003] The stator winding of the doubly-fed asynchronous wind turbine is directly connected to the grid, and the rotor winding is connected to the grid through a back-to-back converter. Because of its characteristics of fast and f...

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Problems solved by technology

[0011] In view of the above defects, the purpose of the present invention is to provide a double-fed fan with low voltage ride through and its low voltage ride through method, aiming to solve the technical problem that the existing fault ride through method cannot realize the non-off-grid operation when the deep voltage drops

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