Power CAD Drafter
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
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):
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:
| 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 compliancereferences/drawing_symbols.md— Drawing legend and symbol standards per GB/T 4728
