Power grid comprehensive frequency modulation method based on frequency modulation capability of doubly-fed fan in wind power plant

Abstract

The invention discloses a power grid comprehensive frequency modulation method based on a frequency modulation capability of a doubly-fed fan in a wind power plant. A concept of wind capacity productis proposed from physical characteristics of a DFIG doubly-fed wind power generator, and a frequency modulation capability of each DFIG device in a wind power plant is measured through the concept ofwind capacity product. Under a condition that a frequency offset of a power grid is smaller than 0.2 Hz, a DFIG fan with the maximum wind capacity product is adopted for independent frequency modulation so that the frequency offset is quickly eliminated; under the condition that the frequency offset of the power grid is greater than 0.2 Hz, power task division is performed according to asize of the wind capacity product of each DFIG device; and in specific details of single frequency modulation and multi-machine cooperative frequency modulation, a wind speed factor is considered, especially when the current wind speed is smaller than arated wind speed, virtual inertia method model parameters are adjusted according to a difference adjustment coefficient calculated according to a wind speedsection where DFIG is located, frequency modulation is made to be faster and more stable, and finally a purpose that a wind power generation frequency is stable under the complex wind power plant anddifferentiated unit conditions is achieved.

Description

technical field [0001] The invention relates to the field of wind power generation, in particular to a method for comprehensive frequency regulation of a power grid based on the frequency regulation capability of double-fed wind turbines in a wind farm. Background technique [0002] Doubly-fed Induction Generator (DFIG) is the most widely used wind generator at present. It is a wound-type asynchronous generator directly connected to a fixed-frequency three-phase grid by a stator winding and a two-way back-to-back installed on a rotor winding. IGBT voltage source converter composition. [0003] According to national regulations, the frequency of the power grid system should be controlled within the range of plus or minus 0.2Hz of the rated frequency error for 98% of the time. When the frequency deviation is greater than 0.2Hz, the power grid should take emergency control measures. However, due to the complexity of wind farms and the differences of wind turbines, if a constan...

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Problems solved by technology

[0004] Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a comprehensive power grid frequency modulation method based on the frequency modulation capability of doubly-fed wind turbines in wind farms, which solves the problem that the existing ideal DFIG control method cannot be used in complex wind farms and differentiated unit conditions. The problem of providing stable power grid frequency under

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