Open Access

ARTICLE

Low-Frequency Oscillation Analysis of Grid-Forming Energy Storage Converters Based on a Multi-Damping Path Model

Qiang Liu¹, Yongqiang Zhou¹, Chaoyang Lu², Zhen Yan¹, Gangui Yan², Cheng Yang^2,*, Yupeng Wang²

1 Xingtai Power Supply Branch, State Grid Hebei Electric Power Co., Ltd., Xingtai, 054001, China
2 Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology, Ministry of Education (Northeast Electric Power University), Jilin, 132012, China

* Corresponding Author: Cheng Yang. Email:

(This article belongs to the Special Issue: New Energy and Energy Storage System)

Energy Engineering 2026, 123(9), 20 https://doi.org/10.32604/ee.2025.073028

Received 09 September 2025; Accepted 21 October 2025; Issue published 06 August 2026

Abstract

The increasing proportion of power generated by new energy has meant that grid-forming energy storage has become a key method for improving power grid flexibility. However, the small disturbance stability problem has become an important challenge. The issue is that grid-forming energy storage is prone to low-frequency oscillation under strong grid conditions. Therefore, this study proposes a multi damping torque model to analyze the small signal stability of grid-forming energy storage converters. The impact of grid strength, operating conditions, and control parameters on the damping characteristics of the low-frequency oscillation by the system was quantitatively evaluated. The results revealed the mechanism underlying the low-frequency oscillation associated with grid-forming energy storage under strong grid conditions and key factors controlling the low-frequency oscillation. The results also provide theoretical guidance for the tuning of grid-forming energy storage control parameters. The accuracy of the multi damping torque model and theoretical analysis were verified using the electromagnetic simulation results.

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Keywords

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