Low-voltage ride through control method of dual-feed wind generating set

Abstract

The invention discloses a low-voltage ride through control method of a dual-feed wind generating set, which comprises the step of controlling a rotor side converter and a network side converter. The low-voltage ride through control method has the technical scheme that: during failure, the rotor side converter controls a wind generating set rotor to accelerate for operation through a manner of limiting a torque current of the wind generating set, unbalance energy in the wind generating set due to voltage drop of a power grid is converted into kinetic energy of the rotor, thus overcurrent in a stator loop and a rotor loop of the wind generating set is reduced; and a feed-forward compensation quantity for reflecting rotor power and direct-current voltage fluctuation is added in a direct-current side voltage control ring of the network side controller, thus momentary fluctuation of the rotor power is balanced and overvoltage of a direct current side is reduced. The low-voltage ride through control method is simple in realization without adding a hardware device, has high reliability and capabilities of effectively improving low-voltage ride through capacity of the dual-feed wind generating set and keeping control of the wind generating set on outputting an active power and a reactive power in a power grid failure period.

Description

Technical field: [0001] The invention belongs to the field of wind power generating set operation control, and in particular relates to a control method for ensuring and improving the low-voltage ride-through capability of a doubly-fed wind generating set when a grid voltage drops suddenly. Background technique [0002] Double-fed wind turbines have been widely used in medium and high-power wind turbines due to their unique technical advantages. As more and more wind turbines are connected to the grid, the new wind power grid-connected guidelines require that the grid-connected wind turbines can still maintain non-off-grid operation when the grid fails, and the wind turbines can recover quickly after the fault is removed. Normal operation means that wind turbines are required to be able to achieve low-voltage ride-through operation. [0003] The voltage drop at the grid-connected point of the wind turbine caused by the grid failure will make the power generated by the wind ...

AI Technical Summary

Problems solved by technology

But these methods still have the following deficiencies: ① need to add a new hardware protection device, thereby increasing the cost of the system and reducing the reliability of the system

③ When a fault occurs, the generator operates as a traditional induction motor, which will absorb reactive power from the grid and affect the voltage stability of the grid

However, these control algorithms are usually too complex for industrial applications, and lack robustness because these algorithms usually rely on the evaluation of certain system parameters and the design of control parameters

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