Power Systems Reference

Domain knowledge for overhead transmission line physics, thermal ratings, and mechanical analysis.

When to Use This Skill

•Implementing thermal models or conductor temperature calculations
•Working with catenary physics (sag, tension, clearance)
•Validating electrical properties (resistance, reactance, impedance)
•Referencing industry standards (CIGRE, IEEE, IEC)
•Applying physical bounds validation
•Reviewing or writing physics algorithms
•Implementing conductor property calculations

Key Reference Files

File	Content
`references/thermal-models.md`	CIGRE TB 601, IEEE 738 thermal rating implementations
`references/conductor-limits.md`	Physical validation bounds and parameter constraints
`references/electrical-properties.md`	Resistance, sag, catenary formulas and calculations
`references/standards-reference.md`	Industry standards summary (CIGRE, IEEE, IEC, EN)

Available Scripts

Script	Usage	Description
`scripts/validate-bounds.py`	`validate-bounds.py -t conductor_temp -v 85`	Validate physics values against bounds
`scripts/convert-units.py`	`convert-units.py 25 C K`	Convert between units (temp, length, power, speed)
`scripts/check-standard-refs.sh`	`check-standard-refs.sh <dir>`	Check for proper CIGRE/IEEE citations in code

Quick Reference

Default Standard

CIGRE TB 601 is the default thermal rating standard. Document any deviations in code comments:

python

# Note: Using CIGRE 601 natural convection formula (Section 4.2.3)
# IEEE 738 differs in treatment of low wind speeds

Physical Bounds (Quick Check)

Parameter	Valid Range
Conductor temperature	-40°C to 250°C
Ambient temperature	-50°C to 60°C
Wind speed	0 to 50 m/s
Solar radiation	0 to 1400 W/m²

Unit Conventions

•Internal: SI units, temperatures in Kelvin
•Display: Celsius for temperatures
•Document: Always include units in variable names or docstrings

Code Patterns

Parameter Validation

Always validate physical parameters at function boundaries:

python

def calculate_conductor_temperature(
    current_a: float,
    ambient_temp_c: float,
    wind_speed_mps: float,
) -> float:
    """Calculate steady-state conductor temperature.

    Args:
        current_a: Line current in Amperes (0 to rated × 2)
        ambient_temp_c: Ambient temperature in Celsius (-50 to 60)
        wind_speed_mps: Wind speed in m/s (0 to 50)

    Raises:
        ValueError: If parameters outside physical bounds
    """
    if not -50 <= ambient_temp_c <= 60:
        raise ValueError(f"Ambient temperature {ambient_temp_c}°C outside valid range [-50, 60]")
    # ... implementation

Standard Citations

Always cite standard section numbers in code comments:

python

# CIGRE TB 601, Section 4.2.3: Natural convection heat loss
# Formula: P_n = pi * D * lambda * Nu * (T_s - T_a)

Testing Patterns

Use pytest.approx() with appropriate tolerances:

python

def test_thermal_model():
    result = calculate_ampacity(...)
    # Thermal calculations: 1e-3 tolerance (0.1% accuracy)
    assert result == pytest.approx(expected, rel=1e-3)

Related Skills

•database-patterns — For persisting physics results
•foundations/code-style — For Python conventions in physics code