Virtual inductance control method, program and system for suppressing frequency oscillation of virtual synchronous generator

Abstract

The invention discloses a virtual inductor control method, program and system for suppressing frequency oscillation of a virtual synchronous generator, and the method comprises the steps: building a system power model before and after the introduction of a virtual inductor, and simulating the additional inductance of an L filter inductor through the feedforward of active power and reactive power according to the principle of power conservation; and then calculating a virtual inductance value required for keeping the system stable under the high-power coupling degree according to a stability criterion. According to the method, only the virtual inductor is introduced to increase the inductance value of a filter, no new inductor needs to be added in the filter, the inductor is added in the control scheme, extra cost and hardware modification are avoided,and meanwhile, an active power and reactive power feedforward virtual synchronous generator (VSG) grid-connected model containing the virtual inductor is established. The root locus of the characteristic value shows that the virtual inductance feedforward control scheme can effectively restrain frequency oscillation of the grid-connected VSG system, the system can stably operate when active power and reactive power are highly coupled, and the steady-state performance and the dynamic performance of the system are kept.

Description

technical field [0001] The invention relates to the technical field of power electronic device control, in particular to a virtual inductance control method, program and system for suppressing frequency oscillation of a virtual synchronous generator. Background technique [0002] In recent years, more and more distributed renewable energy generation has been integrated into the traditional power system, which makes the grid energy structure more and more complex. Due to the grid connection of renewable energy power generation, the power system presents the remarkable characteristics of small inertia and poor damping, which makes the frequency change rate and frequency offset fluctuate in a wide range when the system is disturbed, threatening the safe and stable operation of the AC power system . [0003] Virtual synchronous generator control simulates the inertia and damping characteristics of traditional synchronous generators, and is an emerging technology to improve syst...

AI Technical Summary

Problems solved by technology

Existing inverter or grid-connected VSG oscillation suppression schemes are based on voltage and current inner loop double-loop control to suppress inverter or grid-connected VSG oscillation, which cannot achieve subsynchronous oscillation suppression of grid-connected VSG systems without double-loop control structure

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