Open Access

ARTICLE

Low-Frequency Oscillation Analysis of Grid-Connected VSG System Considering Multi-Parameter Coupling

by Shengyang Lu^1,2, Tong Wang², Yuanqing Liang¹, Shanshan Cheng¹, Yupeng Cai², Haixin Wang¹, Junyou Yang^1,*, Yuqiu Sui^1,3, Luyu Yang²

1 Shenyang University of Technology, Shenyang, 110870, China
2 Electric Power Research Institute of State Grid Liaoning Electric Power Supply Co., Ltd., Shenyang, 110006, China
3 State Grid Liaoning Electric Power Supply Co., Ltd., Shenyang, 110006, China

* Corresponding Author: Junyou Yang. Email:

(This article belongs to the Special Issue: Artificial Intelligence in Renewable Energy and Storage Systems)

Computer Modeling in Engineering & Sciences 2023, 135(3), 2373-2386. https://doi.org/10.32604/cmes.2023.024461

Received 31 May 2022; Accepted 08 August 2022; Issue published 23 November 2022

Abstract

With the increasing integration of new energy generation into the power system and the massive withdrawal of traditional fossil fuel generation, the power system is faced with a large number of stability problems. The phenomenon of low-frequency oscillation caused by lack of damping and moment of inertia is worth studying. In recent years, virtual synchronous generator (VSG) technique has been developed rapidly because it can provide considerable damping and moment of inertia. While improving the stability of the system, it also inevitably causes the problem of active power oscillation, especially the low mutual damping between the VSG and the power grid will make the oscillation more severe. The traditional time-domain state-space method cannot reflect the interaction among state variables and study the interaction between different nodes and branches of the power grid. In this paper, a frequency-domain method for analyzing low-frequency oscillations considering VSG parameter coupling is proposed. First, based on the rotor motion equation of the synchronous generator (SG), a second-order VSG model and linearized power-frequency control loop model are established. Then, the differences and connections between the coupling of key VSG parameters and low-frequency oscillation characteristics are studied through frequency domain analysis. The path and influence mechanism of a VSG during low-frequency power grid oscillations are illustrated. Finally, the correctness of the theoretical analysis model is verified by simulation.

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Keywords

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