Design utility transmission line Assignment
OBJECTIVE:
- Line specification, and Voltage regulation.
- Transformer configuration and selection.
- Single Line diagram configuration.
- Alternative energy lighting specification
Specification :
- Utility connection – 80 Km from 138 KV switching station to building (Bio – Disesel Plant in rural Saskatchewan) 3 wire – triangular line – 3ft spacing.
- Communities( 80Km East Afox Valley).
- Building has 138KV to 4160V Delta – Wye Transformer
- Loads – 1MVA 4160 load, 400KVA 600V Load, 100KVA 208V load(all Static).
- 25 Exterior lights – equivalent to a 250W HPS fixture – to be operated off of alternate energy – capacity -1 day average.
Procedure:
- Design utility transmission line such that conductor is rated at 50% of building load, and breaking stregth of not less than 9,000 pounds force.
- Calculate range of voltage regulation at building – building power factor at main transformer varies from 0.9 to 0.8 lagging.
- Specify Transformers – find actual transformers available, include data sheet all transformers rated so they are operating a 50% load to allow for expansion.
- Size conductor to each one of the main static loads. Conductor sizing such that loading is at 80% at full load.
- Produce a single line diagram in ETAP – and confirm calculations and enter ratings.
- Select exterior lights, and specify alternate energy system (source + storage).
STAGE 1: Line Specification , and Voltage Regulation
- Designing utility transmission line such that conductor is rated at 50% of building load,
Diagram:
Using phase calculation
IL = = = 8.63 A
Using
L= ( + ln() H/m
RT=
