An inertial control method for doubly-fed wind turbines

Abstract

The invention discloses an inertial control method for a double-fed wind turbine. The active power output reference value of the double-fed wind turbine is controlled by a maximum power tracking algorithm; if it is detected through system frequency that the system frequency is normal, the active power output reference value of the double-fed wind turbine is controlled by the maximum power trackingalgorithm, otherwise the active power output reference value of the double-fed wind turbine is controlled by the linear active power output of the rotation speed of the rotor of the double-fed wind turbine; if it is detected through the rotation speed of the rotor of the double-fed wind turbine that rotation speed change rate is less than or equal to the rotation speed change rate threshold valueof the rotor of the double-fed wind turbine, the active power output reference value of the double-fed wind turbine is controlled by the active power output of the rotation speed of the rotor of thedouble-fed wind turbine, otherwise the active power output reference value of the double-fed wind turbine is controlled by the active power output of the rotation speed acceleration of the rotor of the double-fed wind turbine until the system frequency is back to a normal state and then controlled by the maximum power tracking algorithm. Compared with the prior art, transient support can be effectively provided for the system frequency, excessive releasing of the kinetic energy of the double-fed wind turbine can be avoided, and the power dropping amplitude at the recovery moment of rotation speed can be reduced.

Description

technical field [0001] The invention relates to the field of active power control methods for renewable energy sources, in particular to an inertia control method for double-fed wind turbines. Background technique [0002] The wind energy utilization technology is gradually mature and the reserves are very abundant, and the proportion of wind power generation in the power grid is constantly increasing. As the mainstream type of wind farm, doubly-fed wind turbines have the advantages of high power generation efficiency and small converter capacity. However, because doubly-fed wind turbines are connected to the grid through power electronic converters, the speed of the unit is decoupled from the system frequency, which cannot Provide inertial support for the system. Under the background of large-scale wind power grid connection, the decrease of system inertia brings serious frequency stability problems, and it is urgent to introduce wind power inertia control technology. Base...

AI Technical Summary

Problems solved by technology

However, because it establishes the active-time relationship and ignores the speed, it is easy to induce excessive release of rotor kinetic energy, making the rotor speed exceed the minimum speed limit.

And in order to achieve speed recovery, the electromagnetic power needs to be lower than the mechanical power, and the power drop is relatively large at the moment of speed recovery, which will lead to a serious secondary drop in frequency

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