Low-complexity graph-based traveling wave models for HVDC grids with hybrid transmission lines: Application to fault identification

TL;DR

This paper introduces a graph-based, low-complexity traveling wave model for hybrid HVDC grids that effectively describes transient phenomena for rapid fault identification, combining physical and behavioral modeling approaches.

Contribution

It presents a novel, compact modeling method for traveling waves in hybrid HVDC lines, explicitly incorporating grid and fault characteristics for improved fault localization.

Findings

Model accurately describes traveling waves in hybrid lines

Effective fault identification in HVDC grids demonstrated

Model simplifies transient analysis for protection systems

Abstract

The fast protection of meshed HVDC grids requires the modeling of the transient phenomena affecting the grid after a fault. In the case of hybrid lines comprising both overhead and underground parts, the numerous generated traveling waves may be difficult to describe and evaluate. This paper proposes a representation of the grid as a graph, allowing to take into account any waves traveling through the grid. A relatively compact description of the waves is then derived, based on a combined physical and behavioral modeling approach. The obtained model depends explicitly on the characteristics of the grid as well as on the fault parameters. An application of the model to the identification of the faulty portion of an hybrid line is proposed. The knowledge of the faulty portion is profitable as faults in overhead lines, generally temporary, can lead to the reclosing of the line.