Method for controlling wind turbine to participate in power grid frequency modulation based on virtual inertia and pitch angle

Abstract

The invention discloses a method for controlling a wind turbine to participate in power grid frequency modulation based on virtual inertia and a pitch angle. The method comprises the following steps:when a frequency deviation exists between the rated power of a system power grid and the current frequency, calculating a proportionality factor of a tracking curve of the sub-optimal rotating speed-active power of the wind turbine under the control of the virtual inertia; calculating a reference power of an inverter at a rotor side under the control of the virtual inertia; calculating an introduced electromagnetic power at the rotor side inverter according to the frequency change rate, and accumulating the introduced electromagnetic power and the reference power to obtain a total electromagnetic power of the rotor side inverter; calculating the rotating speed deviation of the wind turbine, and adopting the rotating speed deviation of the wind turbine to calculate the electromagnetic powervariation of the rotor side inverter; obtaining an active power of a pitch angle mechanism according to the total electromagnetic power and the electromagnetic power variation, and calculating the pitch angle of the pitch angle mechanism by adopting the active power of the pitch angle mechanism; and controlling the wind turbine to increase captured wind energy and inject the active power into thepower grid according to the pitch angle.

Description

technical field [0001] The invention belongs to the technical field of wind power generation, and in particular relates to a method for controlling wind turbines to participate in power grid frequency regulation based on virtual inertia and pitch angle. Background technique [0002] At present, wind power generation has been rapidly developed in countries all over the world. With the increasing proportion of wind power in the power grid, a series of challenges have been brought to the safe and stable operation of the power system. [0003] At present, the ability to respond to system frequency has become an important feature of "grid-friendly" wind power. As a mainstream model of grid-connected wind power, variable-speed constant-frequency doubly-fed wind turbines (DFIG) can flexibly adjust active and reactive power, but power electronics The converter hides the coupling relationship between the speed of the wind turbine and the grid frequency, which makes it unable to respo...

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Problems solved by technology

[0003] At present, the ability to respond to system frequency has become an important feature of "grid-friendly" wind power. As a mainstream model of grid-connected wind power, variable-speed constant-frequency doubly-fed wind turbines (DFIG) can flexibly adjust active and reactive power, but power electronics The converter hides the coupling relationship between the speed of the wind turbine and the frequency of the grid, which makes it unable to respond to changes in the grid frequency. When large-scale wind turbines are connected to the grid, it will inevitably lead to problems such as reduced system inertia.

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