A Wind Farm Subsynchronous Oscillation Cutting Method Based on Negative Damping Contribution

Abstract

A wind farm subsynchronous oscillation removal method based on negative damping contribution. This method obtains the time domain sequence by collecting the three-phase phase voltage and three-phase phase current of each 35kV collector line of the wind farm and the outgoing line of the booster station, and then the time domain sequence is obtained by Selective filtering, filtering out power frequency components and high frequency components, obtaining the subsynchronous / supersynchronous oscillation component sequence, performing characteristic information calculation on the subsynchronous / supersynchronous oscillation component sequence, and obtaining the subsynchronous / supersynchronous equivalent impedance, and then The impedance of each collector line is sorted according to the resistance characteristics, and the collector line with the largest negative damping contribution is removed according to the ranking until all the collector lines provide positive resistance. According to the contribution of each collection line to sub-synchronous / super-synchronous oscillation, the method can finely and step-by-step remove the wind turbines that generate oscillations, and is suitable for effective prevention of sub-synchronous / super-synchronous oscillations when wind turbines are connected to the grid on a large scale. control.

Description

technical field [0001] The invention belongs to the technical field of power system monitoring and control, and in particular relates to a method for removing subsynchronous oscillations of wind farms based on negative damping contributions. Background technique [0002] Different from traditional generators, new energy generation such as wind and light are integrated into the grid through power electronic devices, and its multi-time-scale control characteristics interact with the characteristics of the grid itself, which may cause sub-synchronization into the harmonic frequency band, resulting in Control instability and oscillation problems that are not found in traditional power systems. In recent years, this kind of problem has gradually become prominent in the power grid, and the scope of influence is wider and wider, and the consequences are more and more serious. In 2014, more than 200 Hz harmonic oscillation occurred in the offshore wind farm in northern Germany thro...

AI Technical Summary

Problems solved by technology

More importantly, the formation mechanism of this subsynchronous oscillation is inconsistent with that of the traditional power system. It is caused by the subsynchronous harmonics introduced by the collection of a large number of new energy sources. The existing monitoring, protection and control methods are no longer applicable.

Images