Single-Phase vs Three-Phase Power Basics

Quand cela s’applique

Use this guide when you need fast clarity on balanced three-phase power relationships and where simplified formulas are valid.

Outil à utiliser

Calculer P, S et Q en triphase equilibre a partir des grandeurs de ligne.

Ouvrir Calculateur de puissance triphasee →

Étapes

  1. 1Identify the measurement basis: line-to-line voltage and line current for balanced three-phase.
  2. 2Compute apparent power with S = sqrt(3)*V_LL*I_L.
  3. 3Compute real power with P = S*cos(phi) and derive reactive magnitude from the power triangle.
  4. 4State whether values are per-phase or total-system quantities.
  5. 5Use full phasor and unbalance analysis if system asymmetry is material.

Exemples

  • Sanity-checking panel loading assumptions during early facility planning.
  • Comparing apparent vs real power impact at different power factors.

Ce qu’il faut éviter

  • Mixing phase and line quantities in one formula.
  • Treating cos(phi) as a signed reactive-direction indicator.
  • Using balanced formulas for strongly unbalanced loads.

Outils associés

Sur le blog

Plus dans Ingénierie

Tous les guides par tâche ou la liste complète sur le hub Ingénierie.

FAQ

Does this tell me if loads are leading or lagging?

No. The basic calculator reports reactive magnitude, not sign from full phasor context.

Can I use this for harmonics-heavy systems?

Not as final analysis; harmonics require true power-quality methods.

Tous les guides par tâche · Outils Ingénierie · Blog