Evaluation of the Impact of High-Bandwidth Energy-Storage Systems on DC Protection

The integration of high bandwidth energy-storage systems (ESS) in compact dc electrical power systems can increase the operational capability and overall flexibility of the network. However, the impact of ESSs on the performance of existing dc protection systems is not well understood. This paper identifies the key characteristics of the ESS that determine the extent of the protection blinding effects on slower acting generator systems on the network. It shows that higher fault impedances beyond that of an evaluated critical level will dampen the response of slower-acting generator systems, decreasing the speed of corresponding overcurrent protection operation. The paper demonstrates the limitations of existing protection solutions and identifies more suitable protection approaches to remove/minimize the effects of protection blinding.