The increasing penetration of inverter-based renewable energy resources is reshaping transmission-line fault characteristics and weakening protection criteria designed for synchronous-generator-dominated grids. This paper proposes an internal-fault identification scheme based on voltage–current coupling characteristic curves (UICs) constructed from voltage and current measurements at both line terminals. Geometric descriptors of the UIC are used to build an ellipsoidal feature space representing normal operating conditions and external faults. Internal faults are identified from the normalized distance between the online feature vector and this space. A local voltage-transient startup criterion is also introduced, and current-transformer (CT) saturation correction is incorporated to reduce distortion in the measured currents. PSCAD simulations under different fault locations, transition resistances, fault types, noise levels, and CT-saturation conditions show that the proposed scheme distinguishes internal faults from external faults and normal operation reliably. Because the criterion depends on line-side coupling features rather than the short-circuit output of a specific power source, it is suitable for protection applications in renewable energy systems with grid-forming inverters.
In recent years, high penetrations of inverter-based resources are posing significant challenges to the medium-voltage networks, in which protection schemes based on high fault currents and unidirectional power flow may not perform as expected. This paper proposes a dynamic fault-detection and relay-coordination scheme...
Muhammad Abdul Rauf, Munira Batool, I. Madni· Energies· 0 citations
This paper presents an integrated energy management and protection framework for sustainable renewable DC microgrids. The proposed system combines energy management, fault detection, selective isolation, and impedance-based fault-distance estimation using local voltage and current measurements. The studied 400 V DC mic...
Hafsa El Meskini, M. Azeroual, A. El Amrani et al.· Sustainability· 0 citations
To improve voltage support at the point of common coupling of renewable energy collection stations connected to weak grids, this paper proposes a synchronous machine-like outer reference generator for a conventional fixed-PQ voltage-source converter (VSC). The proposed versatile static synchronous machine (VSSM) emulat...
Jun Chen, Yu Duan, Xing Ma et al.· Electronics· 0 citations
The study of hybrid multiterminal high-voltage direct current (HVDC) systems revealed different outcomes regarding their performance under fault conditions. Previous research showed that under the fault conditions, the high-voltage direct current (HVDC) voltage experienced a drop to zero, accompanied by a reverse overs...
Olumoroti Ikotun, E. Ojo, M. Kabeya· Symmetry· 0 citations
The increasing replacement of synchronous generators (SGs) by grid-following (GFL) and grid-forming (GFM) inverters is reshaping the dynamic bus characteristics of modern power systems. This transition makes a fixed ideal-voltage-source representation of the upstream main grid increasingly inadequate, especially when t...
The hybrid operation of grid-following (GFL) and grid-forming (GFM) renewable energy units can lead to phase-reference inconsistencies and distorted transient impedance trajectories, which in turn cause maloperation or failure-to-operate of conventional distance protection. To address this issue, this paper proposes a...
