Novel busbar protection scheme for impedance-earthed distribution networks

This practice is an example of how existing infrastructure can be used to resolve problems resulting from single-phase-fault currents. Researchers used Impedance-Earthed Distribution (IED) infrastructure, backboned by an IEC 61850 communication, to create a distributed busbar protection scheme against single-phase-to-ground faults in medium-voltage impedance earthed distribution networks. Implemented by the DSO Stedin in the Netherlands, it also includes distributed protection algorithms for fault detection and fault elimination.  

Highlights

• Use of existing equipment infrastructure to provide busbar protection against single-phase fault currents in high-impedance grounded networks.Distinguishes between healthy and faulty busbar sections using zero-sequence voltage detection in the IEDs in the incoming feeders.
• Development of distributed protection algorithms for fault detection and fault elimination.
• Provides a solution for a unique problem and showcases how academic research can facilitate actual protection applications for electricity systems.

Due to the vast number of substations at the distribution level of the electricity system and increased costs of differential busbar protection, Distribution Systems Operators (DSOs) need cost-effective protection schemes for busbar protection. By using the established IEC 61850 communication between the Impedance-Earthed Distribution and research from the University of Delft, this innovative practice can detect a single-phase-to-ground fault on the busbar system. This practice addresses this challenge and enhances communication with intelligent, high-quality protection schemes, enabling primary and backup busbar protection based on existing infrastructure and without new investments. Currently in use by the DSO Stedin in the Netherlands, this practice has now became a standard part of their protection policy and is currently being implemented in all their MV substations.