The DC Power Flow Approximation

Many network matrices in PowerNetworkMatrices.jl rely on the DC power flow approximation.

Assumptions:

1. Voltage Magnitude: All bus voltages are approximately 1.0 per unit
2. Small Angles: Voltage angle differences are small (< 15°)
3. Resistance: Line resistance is negligible compared to reactance
4. Active Power: Only active power flows are considered

When DC Approximation Works Well:

• Transmission systems (high voltage)
• Normal operating conditions
• Security and market analysis
• Planning studies

When to Be Cautious:

• Distribution systems (high R/X ratios)
• Large angle differences
• Voltage-constrained systems
• Detailed reactive power analysis