LIVEdataset aec-bench@releasetasks 552models 18last submission … · built …
electricalwith-tool

Busbar Forces

Calculates the electromagnetic force per unit length on the centre phase of a three-phase flat busbar arrangement during a symmetrical short circuit using Fm = (mu_0 / 2pi) * (sqrt(3)/2) * ip^2 / a, then derives peak span force and bending stress. Used to verify busbar mechanical adequacy in switchgear and substation design per IEEE 605 and IEC 60865-1.

with-tool: The model is given an executable Python calculator script.

Standards

IEC 60865-1:2011IEEE 605-2008

Tags

busbarelectricalelectromagnetic-forceshort-circuitsubstation

How this task is generated

One template produces many comparable benchmark tasks while keeping the scoring contract fixed.

  1. 01

    Template

    The reusable contract shown on this page.

  2. 02

    Scenario

    An archetype and site context are sampled.

  3. 03

    Difficulty tier

    Inputs may be hidden at harder tiers.

  4. 04

    Task prompt

    The model responds with the declared outputs.

Parameters

Inputs the model receives, and the outputs it is scored on.

Inputs

7 inputs

Always given

Included directly in every task prompt.

5

  • Peak short circuit current

    peak_short_circuit_current_ka

    Peak (asymmetrical) short-circuit current ip

    5 – 200 kA

  • Phase spacing

    phase_spacing_mm

    Centre-to-centre spacing between adjacent busbar phases

    50 – 1000 mm

  • Span length

    span_length_m

    Span length between busbar supports

    0.3 – 3 m

  • Busbar width

    busbar_width_mm

    Width of rectangular busbar cross-section

    20 – 200 mm

  • Busbar thickness

    busbar_thickness_mm

    Thickness of rectangular busbar cross-section (bending direction)

    3 – 20 mm

Optional

Used only when the sampled task needs this part of the contract.

2

  • Support condition

    support_condition

    End support condition for the busbar span

    Derived from the archetype scenario. Optional input. Hidden at hard difficulty.

    simply_supportedfixed_both_ends

  • Busbar material

    busbar_material

    Busbar conductor material

    Derived from the archetype scenario. Optional input. Hidden at hard difficulty.

    copperaluminium

Scored outputs

3 outputs

Force per m n

force_per_m_n

Electromagnetic force per unit length on centre phase (N/m)

Scores if within ±3% of the reference value.

Peak force n

peak_force_n

Total peak force over one busbar span (N)

Scores if within ±3% of the reference value.

Busbar stress mpa

busbar_stress_mpa

Maximum bending stress in the busbar (MPa)

Scores if within ±3% of the reference value.

Difficulty

Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.

easy

All inputs given

LV switchboard, short span, all parameters given including support condition and material

medium

All inputs given

Any voltage level and archetype, all parameters given

hard

Some inputs hidden

Support condition and material hidden, agent must infer from installation context

Hidden inputs

  • Support conditionsupport_condition
  • Busbar materialbusbar_material

Prompt replacement text

The installation is a {{ archetype.description }} ({{ archetype.site_context }})

Task bundle

The exact instruction and parameter contract used to generate this task, pinned to the published library source.

/workspace

  • instruction.md
  • busbar-forces_calc.py

Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.

1You are a senior electrical engineer specializing in substation design and busbar short-circuit withstand analysis.2 3## Problem4 5Calculate the electromagnetic forces on rigid busbars during a three-phase short circuit using the IEEE 605 / IEC 60865-1 method. The busbars are arranged in a flat (coplanar) three-phase configuration with equal phase spacing.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Peak short-circuit current (ip) | {{ peak_short_circuit_current_ka }} | kA |12| Phase spacing (centre-to-centre) | {{ phase_spacing_mm }} | mm |13| Span length between supports | {{ span_length_m }} | m |14| Busbar width | {{ busbar_width_mm }} | mm |15| Busbar thickness | {{ busbar_thickness_mm }} | mm |16{% if support_condition is defined %}17| Support condition | {{ support_condition }} | - |18{% endif %}19{% if busbar_material is defined %}20| Busbar material | {{ busbar_material }} | - |21{% endif %}22{% if archetype_description is defined %}23 24### Installation Context25 26{{ archetype_description }}27{% endif %}28 29{% if tool_available %}30## Available Tool31 32A busbar force calculation tool is available at `/workspace/busbar-forces_calc.py`. Run it with:33 34```bash35python3 /workspace/busbar-forces_calc.py --help36```37 38You may use this tool to verify your calculations or compute values directly.39{% endif %}40 41## Required42 43Calculate the following:44 451. Electromagnetic force per unit length on the centre phase (N/m)462. Total peak force over one busbar span (N)473. Maximum bending stress in the busbar (MPa)48 49## Applicable Standards50 51- IEEE 605-2008 — Guide for Bus Design in Air Insulated Substations52- IEC 60865-1:2011 — Short-circuit currents — Calculation of effects, Part 1: Definitions and calculation methods53 54## Constraints55 56- No internet access is available. Work from engineering knowledge and the provided tool.57- Use the IEC 60865-1 / IEEE 605 simplified method for a three-phase flat busbar arrangement:58 - **Force per unit length on centre phase:**59 Fm = (mu_0 / (2*pi)) * (sqrt(3)/2) * ip^2 / a60 where mu_0 = 4*pi*10^-7 H/m, ip is the peak short-circuit current in amperes, a is phase spacing in metres61 - **Peak force over one span:**62 F_peak = Fm * L63 where L is the span length between supports in metres64 - **Maximum bending moment:**65 M = Fm * L^2 / beta66 where beta = 8 for simply-supported, beta = 12 for fixed-both-ends67 - **Section modulus of rectangular busbar:**68 Z = w * t^2 / 669 where w is the busbar width (mm) and t is the busbar thickness (mm), giving Z in mm^370 - **Bending stress:**71 sigma = M / Z72 Convert units: M in N*m, Z in m^3 (or equivalently N*mm and mm^3), result in MPa73- The three-phase geometry factor sqrt(3)/2 accounts for the vector sum of forces from both adjacent phases on the centre conductor.74- All currents must be converted to amperes and all dimensions to metres for the force formula.75 76## Output Format77 78Show your step-by-step working in Markdown, including the force calculation, bending moment, section modulus, and stress derivation. At the end of your solution, include a JSON block with your final answers in exactly this format:79 80```json81{82 "force_per_m_n": <numeric_value>,83 "peak_force_n": <numeric_value>,84 "busbar_stress_mpa": <numeric_value>85}86```87 88Write your complete solution to `/workspace/output.md`.89

Scenario archetypes

Each generated task is drawn from one of these realistic scenario bands.

Site contexts ground each scenario in a real locale the model can use to infer hidden values.

Lv switchboard

lv_switchboard

Low-voltage switchboard busbar (400-480 V)

commercial-switchroomindustrial-mcc-room
Parameter ranges
peak_short_circuit_current_ka
10 – 50
phase_spacing_mm
60 – 185
span_length_m
0.3 – 0.8
busbar_width_mm
20 – 60
busbar_thickness_mm
3 – 10

Mv switchgear

mv_switchgear

Medium-voltage metal-clad switchgear busbar (11-33 kV)

zone-substation-switchroomindustrial-hv-room
Parameter ranges
peak_short_circuit_current_ka
25 – 80
phase_spacing_mm
150 – 300
span_length_m
0.5 – 1.5
busbar_width_mm
40 – 100
busbar_thickness_mm
5 – 12

Outdoor substation

outdoor_substation

Outdoor air-insulated substation rigid bus (66-132 kV)

transmission-substationbulk-supply-substation
Parameter ranges
peak_short_circuit_current_ka
50 – 200
phase_spacing_mm
300 – 1000
span_length_m
1 – 3
busbar_width_mm
80 – 200
busbar_thickness_mm
8 – 20

Example task

zone-substation-switchroom-mv-switchgear-preview — hard difficulty, some inputs hidden.

Medium-voltage metal-clad switchgear busbar (11-33 kV). zone-substation-switchroom. Required outputs: force_per_m_n, peak_force_n, busbar_stress_mpa

The model sees

Scenario context and visible inputs.

peak_short_circuit_current_ka
25 to 80 kA
phase_spacing_mm
150 to 300 mm
span_length_m
0.5 to 1.5 m
busbar_width_mm
40 to 100 mm
busbar_thickness_mm
5 to 12 mm

Executable tool: busbar-forces_calc.py

The model must infer

Inputs withheld at this difficulty.

  • Busbar material

    busbar_material

  • Support condition

    support_condition

Stand-in text in the prompt

The installation is a {{ archetype.description }} ({{ archetype.site_context }})

The model must produce

The scored JSON answer schema.

{
  "force_per_m_n": <number>,
  "peak_force_n": <number>,
  "busbar_stress_mpa": <number>
}
  • force_per_m_n · scored within ±3%
  • peak_force_n · scored within ±3%
  • busbar_stress_mpa · scored within ±3%