Power Cad Drafter

Auto-generate electrical CAD drawings from survey data and auto-audit against power codes

Auto-generate DXF construction drawings for 10kV and below power distribution projects, and auto-audit against the company design code and national standards.

Trigger

• User provides survey data, hand-drawn sketches, or design task brief
• User requests electrical single-line diagrams, layout plans, or system diagrams
• User requests drawing review or verification

Prerequisites

bash

python3 -m pip install ezdxf pyyaml

Company code must exist: workspace/电力行业施工图设计规范V1.0.md

Workflow

1. Parse Input Data

Extract structured survey data from user input or parse hand-drawn sketches via vision.

Recommended input format (YAML/JSON):

yaml

project:
  name: "XX小区配电工程"
  type: "residential"
survey:
  building_floors: 18
  units_per_floor: 6
  total_area_sqm: 25000
  substation_dimensions: [8.5, 6.2]

2. Design Parameter Inference

Infer design parameters per the company code:

Item	Input	Output Rule
Load calculation	Area, units, load density	Demand factor method
Transformer	Load, location	Dry/oil, D,yn11, standard capacity
Main wiring	Load grade, transformer count	Single bus / sectionalized
Grounding	Substation location	TN-S (indoor), TN-C-S (outdoor)
Cable	Transformer capacity, routing	Ampacity + thermal + voltage drop
Room layout	Equipment count, dimensions	Aisle width, fire rating, noise

3. Generate DXF Drawings

Run scripts/dxf_generator.py to produce:

Drawing	Suffix	Content
Single-line diagram	_single_line.dxf	10kV and 0.4kV primary system
Layout plan	_layout.dxf	Equipment positioning, dimensions, aisles
Grounding plan	_grounding.dxf	Grounding electrodes, equipotential bonding
Cable routing	_cable.dxf	Trench/bridge paths, cable labels

4. Auto-Audit

Run scripts/audit_engine.py to check against the code and produce a Markdown report.

Core checklist:

• Load grade matches power supply configuration
• Transformer capacity ≤ limits (dry ≤1250kVA public, oil ≤630kVA public)
• Wiring group D,yn11
• HV switchgear IP ≥ IP4X, five-prevention interlock
• LV breaker breaking capacity ≥ short-circuit current
• TN-S grounding mandatory for indoor substations
• Substation roof fire rating ≥ grade 2
• Aisle width ≥ 1.5m (fixed) / 1.8m (drawer)
• Bare conductor height ≥ 2.5m
• Cable sections ≥ minimums (service ≥10mm² copper, main ≥150mm²)
• Grounding resistance ≤ 4Ω (≥100kVA transformer)
• Meter height 0.8–1.8m
• Reactive compensation 20%–40% of transformer capacity

Report format:

markdown

| Category | Item | Result | Design | Required | Clause | Remark |
|----------|------|--------|--------|----------|--------|--------|

Deliverables

project_name_cad_package.zip containing:

• drawings/ — DXF files (4 sheets)
• design_params.json — All inferred parameters
• audit_report.md — Audit report with pass/fail and corrective actions
• equipment_list.csv — Bill of materials

Scripts

• scripts/dxf_generator.py — Core DXF drawing engine (single-line, layout, grounding, cable)
• scripts/audit_engine.py — Rule-based audit engine, loads design params and checks compliance
• references/drawing_symbols.md — Drawing legend and symbol standards per GB/T 4728