Wind power plant power external characteristic modeling method

Abstract

The invention discloses a wind power plant power external characteristic modeling method. The method comprises the following steps of based on average wind velocity obtained by a wind measuring tower in a wind power plant region, in consideration of fan arrangement and wind direction, calculating average input wind speed at hub height of each fan in the wind power plant through a wake model, and building wind speed spatial distribution in the wind power plant; in consideration of own paddle rotary sampling of fan and fan inertia, converting the average wind speed at the hub height into an equivalent wind speed time sequence at a rotating shaft; in consideration of spatial transmission of wind speed, calculating time delay of wind speed from an upstream set to a downstream set, obtaining equivalent wind speed time sequence based on consideration of time delay, and building a complete wind power plant wind speed spatial-temporal distribution; and in consideration of conditions of pitch angle, yaw angle and fan corrective maintenance, calculating wind power output based on consideration of wind power plant control and operating state. Feasibility and reasonability of the provided method are verified by a simulation example on the basis of geographic data and fan parameters of a certain actual wind power plant. The modeling method has good promotional value and application prospect.

Description

technical field [0001] The invention belongs to the field of power system operation and control, and relates to a modeling method for external power characteristics of a wind farm, in particular to a modeling method for external power characteristics of a wind farm considering the temporal and spatial distribution characteristics of wind speed and the operating status of wind turbines. Background technique [0002] With the large-scale development of wind power generation, wind power has brought great challenges to the safe operation and dispatching control of the power grid. Providing accurate wind farm power output to the power system is crucial to the safe production of electricity. [0003] The wind power modeling based on historical power data cannot truly reflect the change law of the actual power of the wind farm due to the influence of the side-limited output of the grid. [0004] For wind power modeling based on wind speed prediction, the establishment of wind spee...

AI Technical Summary

Problems solved by technology

The harmonic synthesis method using trigonometric function superposition has high precision, but it cannot describe the correlation of wind speed among fans, and the calculation amount is large; the linear filtering method based on digital filtering technology has small calculation amount and fast speed, and at the same time, the temporal and spatial correlation between wind speeds is considered. However, it is mostly suitable for simulating the time history of wind speed in the vertical direction of high-rise buildings;

[0006] (2) Based on the power spectral density function (PSD) of wind speed, combined with the spatial correlation matrix in the wind farm, considering the factors such as wind turbine rotation turbulence, tower shadow effect and wind shear, the equivalent wind speed model of the wind turbine in the wind farm is established; usually The input of this type of method is the uniform wind speed of the whole field, and the spatial scale range is large, so it cannot be accurate to each fan;

[0007] (3) Combined with the spatial physical relationship in the wind farm, use the analytical method or fluid dynamics calculation method to describe the wind flow process in the wind farm through the wind speed at a certain fan, and calculate the wind speed of other fans in the field; use the fluid mechanics calculation method to describe the wind farm The distribution of wind speed and wind direction under different conditions in the country, but the model has high requirements for input parameters and high computational complexity; the wake model is used to describe the flow field movement and wind speed changes on the back of the fan. Although the calculation is simple and meets the accuracy requirements, it does not consider the wind speed propagation. delay effect

[0009] In addition, due to cost constraints, wind speed monitoring and forecasting are generally only accurate to the wind farm level and minute level, but cannot be refined to the second-level power output of each wind turbine

Images