Application of Superconducting Fault Current Limiter as a Virtual Inertia for DC Distribution Systems

Abstract

DC distribution systems can provide effective solutions for integrating renewable energy sources in future power systems. The low inertia of the DC distribution system causes several problems regarding stability and fault response. For stability, this low inertia represents a major cause for instability and voltage oscillations, especially with constant power loads. For fault response, the low inertia results in very high fault currents with a significant rate of rising and limited damping. This study aimed to use a superconducting fault current limiter (SFCL) as virtual inertia for DC distribution systems under various disturbances and fault conditions. The system description and modeling are first presented, including the detailed dynamics of SFCL. The stability analysis for the DC system is carried out using the Hurwitz criterion, from which the suitable range of SFCL resistance is identified. Considering this range and fault current limitation, an SFCL resistance of 1.5 Ω is adopted. The whole system is implemented using PSCAD/EMTDC software. A series of case studies are investigated to validate the effectiveness of SFCL in strengthening the inertia of the DC system. These case studies include sudden variations in supply voltage, sudden load changes, and faults. SFCL could successfully suppress voltage oscillations, keep voltage stability, and limit fault currents.

Applications of IoT and digital twin in electrical power systems: A comprehensive survey

“…The second challenge is the vulnerability to instability in electrical grids with a limited capability of reactive power support from RESs [4]. The third challenge is the low inertia of renewable energy sources causing a deteriorated frequency response, high rising rate of fault currents and weak resistance to power disturbances [5][6][7]. The fourth challenge is the negative impact on the power quality of electrical grids when integrating renewables [8].…”

Superconducting fault current limiter (SFCL) for a power electronic circuit: experiment and numerical modelling

“…The successful foundation of SFCLs working properly in these practical compact systems could also be beneficial for promoting SFCLs to be accepted by large-size high voltage/current systems and industrial marketplaces, and then SFCLs can be favourably installed into a wide range of power transmission and distribution systems in the future. Although different types of SFCLs have been investigated and technically demonstrated in the power distribution networks up to 10 kV level [26][27][28][29][30], most of the literatures focus on the fault ride through from the power generation [31][32][33], or short-circuit fault in the power transmission [34][35][36][37]. To date, very few groups have considered the self-acting protection of the power electronic devices by employing a compact-size low-cost SFCL unit.…”