Protection analysis for plant rating and power quality issues in LVDC distribution power systems

Low Voltage DC (LVDC) distribution systems have the potential to be considered as an efficient platform for facilitating the connection of more distributed energy resources. The applications of LVDC are still at an early stage due to the lack of mature experience and standards. Over and above, the protection challenges that are presented by integrating DC installations in existing AC systems are one of the key issues that are delaying the wide uptake of LVDC technologies. In response to these issues, this paper discusses the international installation progress of LVDC systems and their relevant standards in different sectors. This includes data centres, buildings, and utility last mile distribution systems. The paper also investigates the impact of using traditional LV protection methods on the performance of a faulted LVDC network, and on the associated post-fault power quality performance. A typical UK LV network is energised using DC and modelled in PSCAD, and used for the protection studies under different DC fault conditions.