Method and system for acquiring full power range harmonic characteristic model of new energy generating set

Abstract

The invention discloses a new energy generator set full power range harmonic characteristic model acquisition method and system. the method comprises the steps of acquiring a three-phase output voltage and a three-phase output current in a new energy generator set power generation test; performing fast Fourier transform on the three-phase output voltage and three-phase output current to acquire spectrum information of voltage and current data; acquiring each harmonic impedance under different working conditions according to the voltages and currents of the new energy generator set under the different operation conditions; and fitting each harmonic impedance acquired by multiple tests by using a polynomial least square method o acquire the final harmonic impedance characteristic model of the new energy generator set. The harmonic impedance characteristic model within the full power range acquired by using the method is universal, meanwhile performs analysis based on actually measured running data, and is higher in accuracy and reliability.

Description

technical field [0001] The invention belongs to the technical field of harmonic models of new energy power generation equipment (wind power generation, photovoltaic power generation), and specifically relates to a method for obtaining a harmonic impedance model of a new energy generating set in the full power range. Background technique [0002] With the continuous implementation of energy conservation and emission reduction policies, the proportion of new energy (wind power, photovoltaic) energy has increased rapidly, a large number of new energy power generation equipment has been connected to the grid, and the scale of renewable energy consumption in the grid has also increased accordingly. A large number of new energy generating sets are connected to the grid through converters composed of power electronic switching devices as the basic components. The analysis of unit harmonic components and harmonic models is helpful for people to propose corresponding harmonic suppres...

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Problems solved by technology

[0003] For a long time, on the one hand, the establishment of the harmonic model of the new energy unit uses the electromagnetic transient offline simulation software for numerical simulation to model the harmonic characteristics of a single unit, but because of the uncertainty of the distribution parameters, the discretization The truncation error of the algorithm and other factors make it impossible for the main circuit parameters and control algorithm parameters in the simulation model to be completely consistent with the actual equipment, which may cause the harmonic model to be inaccurate; on the other hand, the operating state of the new energy unit has full power However, the previous harmonic modeling method based on measured data was often carried out under one operating condition, and its harmonic characteristic results were not universal and could not meet the needs of new energy units.

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