A comprehensive control method and system for wind turbines to participate in system frequency regulation

Abstract

The invention discloses an integrated control method and system for a wind generating set participating in system frequency modulation. The method comprises the steps of: obtaining system frequency, of a grid connection point of a wind power plant, the wind speed v of a generator set and the rotation speed of the motor of the generator set; performing active power control by an auxiliary speed controller and an auxiliary frequency controller; and performing active power control by the auxiliary speed controller, wherein the active power control comprises: determination of the sizes of the rotation speed of the motor of the generator set, the optimal rotation speed [Omega]opt corresponding to the wind speed v of the generator set and 1.01 [Omega]opt to obtain a corresponding first mark value and determine whether the auxiliary speed controller participates in control or not according to the first mark value. Through control of the rotation speed of the motor of the generator set by theauxiliary speed controller, when the active power injected to the power grid by the generator set is larger than the maximum mechanical power captured by the generator set, the rotation speed of the motor of the generator set is continuously decreased to finally cause a phenomenon of shutdown so as to improve the robustness of the system operation.

Description

technical field [0001] The invention relates to the technical field of wind power generation control, in particular to a comprehensive control method and system for wind power generators to participate in system frequency modulation. Background technique [0002] With the depletion of traditional energy sources such as coal and the increasing pollution of nature caused by the use of fossil energy for power generation, the power industry is seeking some new energy power generation methods to replace some of the traditional power generation methods. Due to the richness and cleanness of wind energy, wind power has developed rapidly in recent years, its proportion in the power grid has been increasing, and its impact on the power grid has become greater and greater. It has become an important part of the power system. The issued national standard GB / T 19963-2011 puts forward clear requirements for active power regulation of wind farms, and wind power generation should have the r...

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Problems solved by technology

[0006] The frequency modulation ability of the virtual inertia method is limited. During the frequency control process, due to the release of rotational kinetic energy and the decrease of the speed, the wind power capture ability will be reduced. Only a short-term frequency modulation support can be performed, otherwise the wind turbine will be shut down. Improper control can easily cause frequency secondary shock

[0007] Most of the existing load shedding and frequency modulation technologies rely on a certain power function to calculate the reference value of the speed and pitch angle under the current working condition. This control method requires complex calculations, and its control effect depends on the accuracy of the power function. degree, the robustness is also poor

[0008] That is to say, whether it is the maximum power point tracking strategy based on vector control widely used by variable-speed constant-frequency wind turbines or the use of its own mechanical energy storage characteristics to realize the virtual inertia method of using the rotational kinetic energy of the wind turbine itself to participate in system frequency modulation and the use of active power The load shedding and frequency modulation technology of power backup has the problem of poor robustness

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