Work

Improved differential protection method for flexible low-frequency transmission system based on additional current compensation

Year: 2025

Type: article

Abstract: • The differential protection boundary and adaptability under NVS is analyzed. • An additional current compensation introduced to improve the sensitivity of the proposed method. • The proposed method fully considers the influence of fault control strategy. • The proposed method can effectively identify faults under noise and higher fault resistance. Low-frequency transmission systems (LFTS) emerge as a competitive solution to the problem of long-distance offshore wind transmission. Because the control strategy on both sides of the line will affect the phase and amplitude characteristics of the fault current, the working performance of the traditional differential protection (TDP) is weakened. Therefore, an improved differential protection (IDP) method based on negative sequence voltage cooperative control is proposed in this paper. Firstly, this paper focuses on the negative sequence control strategy of the modular multilevel converter (M3C). The fault characteristics of differential current and break current under the control strategy are discussed. Secondly, the boundary conditions and adaptability of traditional differential protection using a negative sequence cooperative control strategy are discussed. Then, this paper introduced an additional adaptive current with amplitude and phase angle compensation, which makes the change of differential current and braking current adaptive, so as to improve the sensitivity of the differential protection method. The boundary conditions and adaptability of the method are analyzed. Finally, the effectiveness of the improved method for differential protection of flexible low-frequency transmission systems was verified using PSCAD simulation. Simulation results verified higher sensitivity and 300 Ω fault resistance capability in the proposed method. In addition, the protection method satisfies the differential protection requirements for low-frequency transmission systems. © 2017 Elsevier Inc. All rights reserved.

Source: International Journal of Electrical Power & Energy Systems

DOI: 10.1016/j.ijepes.2025.111212

Authors: Junjie Hou, Jingjing Cao, Yanfang Fan, Guobing Song, Xiaofang Wu

Institutions: Xinjiang University, Xi'an Jiaotong University

Language: English

Topic: Power Systems Fault Detection

Subfield: Control and Systems Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Industry, innovation and infrastructure, Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,920