Installation

In Blender open Edit, Preferences, Get Extensions, then use Install from Disk and pick the power_line_generator zip.

Usage

1. Open the Power tab in the 3D viewport sidebar (N). Click the big picture to browse the designs, then press Add Power Line to place one at the 3D cursor. With a curve selected the line follows the curve; with several objects selected, Wire Selected Objects strings cables between them. You can also use Shift+A, Mesh, Power Line.
2. The card at the top shows the design, the line length, the number of supports, the wire length and sag, the ground clearance and the face count, plus the main sizes. Surprise makes a new random line and Vary changes the current one a little.
3. The icon tabs hold every setting: Route (straight, curve or objects, span, terrain, dead ends), Support (type, height, bracing, section), Head (layout, voltage, arms, insulators), Wires (bundle, diameter, sag, earth and comm wires, spacers, dampers, markers), Catenary (masts, cantilevers or portals, contact wire, tracks), Equipment (transformers, streetlights, substation), Finish (paint, rust, wood, insulator colors) and Parts (part visibility, detail level, Convert to Mesh).
4. When the line follows a curve or stands on a terrain, edit the curve or the ground and the line rebuilds. Convert to Mesh keeps it as plain meshes; Delete Line removes it with all its parts.

All sizes are in meters. The root empty sits on the ground at the start of the line and the line runs along its Y axis. Sag is given in percent of the span and solved as a true catenary.