Why are buses in a power network shown as horizontal and vertical lines

[smilingbuddha]

This is a very very basic question on power systems.

A power system is essentially a graph, where the buses are the graph nodes and the edges represent interconnections between the graphs.
However in text-books, instead of representing a node as a dot / filled circle it is always represented by a straight-line which is parallel to
either side of a page.

Also if multiple edges are incident on the bus (node) like this
then when the edges are shown as non-intersecting on the bus, ie near the buses they are represented as parallel lines.

Why is this?

 

[davidbeach]

Graphs? Edges? What are you talking about? Buses are buses and lines are lines. I suppose you could draw your buses diagonally if you really wanted but that isn't the generally done thing. Dots wouldn't be very practical for most buses.

 

[mgtrp]

Actual buses in substations, in MCCs, in panelboards are usually straight lines. Most symbols bear some resemblance to the actual construction of the equipment.

 

[DRWeig]

In ETAP, buses are shown as either lines or nodes. Choice depends on how many connections are made to it, and whether voltage drop along the bus is important to you.

Best to you,

Goober Dave

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[EEJaime]

As opposed to what? Flowers?

 

[jraef]

A power system is essentially a graph, where the buses are the graph nodes and the edges represent interconnections between the graphs.

This statement, (I guess the core premise of the post?) makes almost no sense to me.

I think a power system is little tweeting bird chirping in a meadow. A power grid is a wreath of pretty flowers which smell BAD. Are you sure your circuits are registering correctly? Your ears are green.

"Will work for (the memory of) salami"

 

[xnuke]

It makes sense to me. He's using graph theory to describe a power system.

smilingbuddha - the representation is the way it is because graph theorists weren't initially responsible for modeling power systems, electrical engineers were.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[EEJaime]

This thread has gone way over the top. LOVE IT. I couldn't figure out what that question meant with a roadmap! Wow.
Good day,
EEJaime

 

[smilingbuddha]

I am a complete newbie to the field, and I made no pretensions in the question to the contrary.

jraef, my circuits are registering correctly.

 

[PHovnanian]

Good point about graph theory. However, there are more nodes in a power system representation than the busses. So the schematic representation of a bus as a line conveys additional information to engineers and technicians than a simple node. And its not a big leap for those thinking in terms of graphs to include several types of connection symbols as a node. Showing everything as one symbol would eliminate information important to other users.

 

[juleselec]

Buses can sometimes be shown as circles or squares, particularly in distribution networks where the network diagram is geographically accurate and overlaid on a GIS map (e.g.

http://www.digsilent.de/tl_files/digsilent/files/powerfactory/powerfactory-interfaces/gis2.gif).

I've also seen circular nodes to represent very large transmission networks, e.g. the ENTSO-E grid.

But the normal convention is to use lines to represent buses for the reasons already given here, e.g. real busbars are usually lines not circles, visual clarity, etc etc