Protection Scheme of a Last Mile Active LVDC Distribution Network with Reclosing Option

Saeed Jamali,Chul-Hwan Kim,Gi-Hyeon Gwon,Syed Bukhari,Muhammad Khan,Chul-Ho Noh,Muhammad Mehdi

doi:10.3390/en11051093

Saeed Jamali, Chul-Hwan Kim + Show 5 more

Open Access

https://doi.org/10.3390/en11051093

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Journal: Energies	Publication Date: Apr 28, 2018
Citations: 11	License type: CC BY 4.0

Affiliation: Sungkyunkwan University

Abstract

A low voltage direct current (LVDC) distribution network is a promising technology to meet the standards of future energy demands for smart loads. An LVDC distribution network can not only supply efficient, smooth and clean energy, but also makes the integration of renewable energy resources in the distribution system easy. A major obstacle in the implementation of the LVDC distribution network is the protection of the network during abnormal grid conditions, such as transients and faults. This paper analyzes DC fault characteristics considering an LVDC distribution network, highlights the worst case scenario during a fault and protection related issues and proposes the protection schemes for the LVDC network. In the proposed protection scheme, a fault is detected and located through superimposed components. To minimize the effect of the DC fault on the distribution network, distributed fault current limiters are introduced and the final decision to disconnect or reconnect the affected line is made on the basis of the type of fault. In addition, a reclosing scheme for a temporary fault is proposed to avoid high inrush currents and false tripping, which eventually increases the reliability. A fast communication-based backup protection is also suggested, and to reduce dependency, a secondary backup is used in the case of communication delay or failure. The proposed scheme is verified using the modified IEEE 13 node test system, which is implemented in ATPDraw. The results show that the proposed scheme can successfully detect, locate and limit a DC fault in an LVDC distribution network with different fault resistances or locations. Moreover, the network is restored successfully in the case of temporary faults.

Highlights

IntroductionDevelopments in power electronics have made it possible for DC networks to fulfill future high quality energy demands [1,2]
The results illustrate that a normal reclose during a temporary fault produced an inrush current of almost 3000 A in the case of the radial line; the high value of inrush current could lead to a false tripping or even cause a threat to the voltage source converter (VSC), whereas through the proposed reclosing method, the inrush current was reduced and the fault-affected line restored with minimum impact on the distribution line as several comparisons were made to highlight the difference
The network behavior during a fault must be studied carefully, and protection issues must be solved before its wide adoption

Summary

Introduction

Developments in power electronics have made it possible for DC networks to fulfill future high quality energy demands [1,2]. A low voltage DC (LVDC) distribution network has high efficiency and is more compatible for the integration of distributed generation (DG) because of the absence of the frequency and phase angle [3,4]. Despite various benefits offered by an LVDC distribution network, there are several challenges associated with the implementation of DC distribution networks. One of the most critical issues is the protection of a DC network during the faults because the fault characteristics of a DC network are much different from AC grids. Protection standards and guidelines that can be widely accepted in industrial and commercial applications have not been proposed yet [5]

Results

Discussion

Conclusion