Practical method for suppressing subsynchronous oscillation of wind power plant by SVG based on PIR control

Abstract

The invention discloses a practical method for suppressing subsynchronous oscillation of wind power plant by SVG based on PIR control, being applied to the SVG device, the SVG device is connected in parallel on the outgoing bus between the wind power plant and the power grid through a transformer, in order to suppress the subsynchronous oscillation of wind turbine generator, a resonant regulator is connected in parallel to the traditional PI regulator, and the resonant frequency parameters in the resonant regulator are dynamically modified according to the main oscillation frequency of DQ axiscurrent detected in real time. The method effectively suppresses the phenomenon of wind power plant subsynchronous oscillation. The control structure is simple and easy to be realized in engineering.

Description

technical field [0001] The invention relates to the technical field of electric power systems and automation thereof, in particular to a practical method for suppressing subsynchronous oscillations of wind farms based on PIR-controlled SVGs. Background technique [0002] my country's wind energy resources and loads are distributed inversely. With the increase in the proportion of power electronic devices and renewable energy connected to the grid, the unique multi-scale control mechanism and low-inertia broadband response characteristics of power electronic conversion technology have significantly changed the dynamic characteristics of the power system. The problem of low-frequency oscillation and subsynchronous oscillation in the power grid connected to the new energy grid has become increasingly prominent. In recent years, subsynchronous oscillation in regional power grids involving wind turbines has occurred in many regions, causing large-scale wind turbines to go off-grid...

AI Technical Summary

Problems solved by technology

However, the current speed deviation detection accuracy of fans is low, which is difficult to meet the control accuracy and affects the control effect

In addition, this control method is based on the known subsynchronous oscillation frequency, which is not suitable for the change of subsynchronous oscillation frequency in wind farms.

There are also SVC-based devices to suppress subsynchronous oscillations, but as passive devices for dynamic reactive power support, SVC devices usually have different phase shifts due to fundamental susceptance modulation at different frequencies, and their control design and parameters are usually aimed at specific oscillation frequency bands. When the oscillation frequency changes, the original control parameters may not be applicable, and the robust suppression of sub / supersynchronous oscillations with changing characteristics currently faced cannot be achieved

[0004] For example, the patent CN106443263A in the prior art discloses a method based on SVG to suppress subsynchronous oscillation caused by wind turbine grid connection. This method needs to set parameters in advance according to the frequency band of subsynchronous oscillation for a specific subsynchronous frequency. Synchronous oscillation presents the characteristics of oscillation frequency drift and change, and it is difficult to predict the oscillation frequency under complex power grids

[0005] For example, the patent CN106300395A in the prior art discloses a given feed-forward control method based on SVG to dynamically suppress the subsynchronous oscillation of the power grid. Although this method uses a band-pass filter, it can suppress the oscillation within a certain frequency range, but with the oscillation When the frequency changes from the bandwidth center frequency to the bandwidth edge frequency, the suppression effect gradually weakens

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