Work

Accurate asymmetric fault modelling and analysis for offshore HVDC systems

Year: 2026

Type: article

Abstract: This paper provides an accurate asymmetric fault modelling method for offshore high-voltage direct current (HVDC) systems, which provides theoretical guidance for the control and protection design of offshore wind power plants (WPPs) and the modular multilevel converter (MMC). Different from the independent modelling under positive- and negative-sequence in classic power systems, the phase angle of the negative-sequence control in the WPPs is normally obtained from the phase-locked loop in the positive-sequence control, i.e., the control modelling under the negative-sequence is coupled with that of the positive- sequence even during fault steady state. On this basis, the controls of WPPs will interact with those of the MMC and will vary with the fault parameter variation and operation mode switching, rendering cumbersome fault analysis and protection design. In this scenario, this paper reveals the dual-sequence coupling and multi-converter interaction with rigorous derivations, based on which it demonstrates the overcurrent of the MMC due to grounding resistance and the loss of negative-sequence current of the WPPs due to voltage-dependent current injection, those bring new thoughts to the control and protection design of offshore HVDC systems. Finally, the correctness of the theoretical modelling and fault analysis is proved by the simulation results.

Source: International Journal of Electrical Power & Energy Systems

DOI: 10.1016/j.ijepes.2025.111529

Authors: Haihan Ye, Wu Chen, Hongchun Yuan, Junyi Zheng

Institutions: Changzhou Institute of Technology, Southeast University

Language: English

Topic: HVDC Systems and Fault Protection

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,920