Protection of a multiterminal DC compact node feeding electric vehicles on electric railway systems, secondary distribution networks, and PV systems

This paper describes a multiterminal DC compact node consisting of voltage-source converters and DC-DC converters as a promising arrangement to feed electric vehicle (EV) charging stations with renewable power sources. This research analyzed the behavior of the node currents under DC faults, and more specically their natural response, which can produce challenging electrical protection requirements. An electrical protection system was thus designed based on the use of protective devices that included protective relays, solid state circuit breakers and hybrid circuit breakers. These protective devices monitor local readings to detect and isolate DC faults as quickly as possible. This highlighted the fact that there are devices, available on the market, that comply with the fast response requirement to prevent damage or destruction of the converters andlter capacitors of the node.