A low-voltage ride-through control method for doubly-fed wind turbines based on inductance simulation

Abstract

The invention discloses a doubly-fed wind turbine generator set low-voltage rid through control method based on inductance simulation, and belongs to the technical field of wind power generation. When a fault occurs in a power grid, rotor side converter equivalent port impedance of the doubly-fed wind turbine generator set is simulated into a pure inductance form, an inductance value is dynamically adaptively adjusted in real time according to rotor voltage and current constraints, voltage and current margins of the rotor side converter can be made full use of, a rotor voltage requirement is lowered and rotor fault current are reduced, and a controllable low-voltage ride through capability of the doubly-fed wind turbine generator set is improved. The method provided by the invention can also effectively suppress electromagnetic torque pulsation, and has the advantages of being clear and definite in physical conception, and being simple in structure.

Description

technical field [0001] The invention belongs to the technical field of wind power generation, and more specifically relates to a low-voltage ride-through control method of a doubly-fed wind turbine based on inductance simulation. Background technique [0002] With the increasing penetration of wind power in the power grid, modern wind power grid-connected regulations require that wind turbines can maintain continuous operation without disconnecting from the grid during grid faults, and can provide reactive power support to the grid within a specified time, that is, low voltage ride through requirements. [0003] Due to the advantages of variable speed and constant frequency, small capacity of excitation converter, and independent decoupling control of active and reactive power, doubly-fed wind turbine has become the main model of current wind turbines. However, since the stator of the double-fed motor is directly connected to the grid, it is particularly sensitive to grid vo...

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Problems solved by technology

Literature [3] proposed that the rotor current command should track the stator current according to a certain ratio. This method can effectively reduce the rotor current during the fault period, but the required rotor voltage is relatively high

These control methods only focus on reducing the rotor voltage or suppressing the impact of the rotor current, and fail to coordinate the distribution relationship between the rotor voltage and the rotor fault current during the grid fault, so that the capacity of the rotor converter cannot be fully utilized to achieve Low voltage ride through of doubly-fed wind turbines

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