A dc power line for a light-rail system carries

Direct current (DC) power lines are integral components in electricity distribution, particularly in applications like light-rail systems. They carry a unidirectional, constant current from power generation sites to the places of consumption. [pdf]

Single line diagram solar power plant

The single line diagram, or SLD sheet, is an essential component of the electrical drawing set for a utility scale solar power plant. It’s a simplified schematic diagram that illustrates the overall electrical system from the panels all the way out to the point of interconnection. [pdf]
[FAQS about Single line diagram solar power plant]

Single line diagram power system

In , a single-line diagram (SLD), also sometimes called one-line diagram, is a simplest symbolic representation of an electric power system. A single line in the diagram typically corresponds to more than one physical : in a system the line includes the supply and return paths, in a system the line represents all three phases (the conduc. [pdf]