Open Access

ARTICLE

Analysis of Sub-Synchronous Oscillation of Virtual Synchronous Generator and Research on Suppression Strategy in Weak Grid

Chongyang Zhao, Wei Chai, Beibei Rui, Lin Chen^*

Jianbi Power Plant of National Energy Group, Zhenjiang, 21200, China

* Corresponding Author: Lin Chen. Email:

Energy Engineering 2023, 120(11), 2683-2705. https://doi.org/10.32604/ee.2023.029620

Received 16 December 2022; Accepted 13 April 2023; Issue published 31 October 2023

Abstract

At present, the direct drive permanent magnet synchronous generator (DD-PMSG) grid connected system based on virtual synchronous generator (VSG) control will experience power oscillation at sub synchronous frequencies. The mechanism and characteristics of this new type of sub-synchronous interaction (SSI) are not yet clear, and the system cannot recover to steady state solely based on the characteristics of VSG itself. Especially when connected to a weak current network, oscillations are more pronounced, affecting the stability of the system. In severe cases, the system may trigger shutdown protection and be disconnected from the network. Existing research has only analyzed the oscillation mechanism under this phenomenon and has not proposed corresponding control strategies. This article proposes a VSM control strategy based on the VSG control algorithm, which balances the dq axis component of voltage and current, and improves the voltage and current loop of VSG control to reduce the impact of sub-synchronous oscillation (SSO) on the power grid. In MATLAB/Simulink, a simulation model of the proposed control strategy was built to verify its correctness and effectiveness.

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Keywords

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