Three-Phase Power Calculator

Three-Phase Power Formulas

Balanced Three-Phase (Star or Delta)

P = √3 × V_LL × I_L × cos φ = 3 × V_LN × I_L × cos φ

Q = √3 × V_LL × I_L × sin φ = 3 × V_LN × I_L × sin φ

S = √3 × V_LL × I_L = √(P² + Q²)

PF = cos φ = P / S

Unbalanced Three-Phase

P_total = P_R + P_Y + P_B = V_RI_Rcosφ_R + V_YI_Ycosφ_Y + V_BI_Bcosφ_B

Q_total = Q_R + Q_Y + Q_B = V_RI_Rsinφ_R + V_YI_Ysinφ_Y + V_BI_Bsinφ_B

S_total = √(P² + Q²)

Star ↔ Delta Conversion

V_LN = V_LL / √3 = V_LL / 1.7321

I_Δ = I_L / √3 (Delta phase current)

PF Correction: Q_C = P × (tan φ₁ − tan φ₂) [kVAR]

Standard Voltage Levels (IS 12360 / IEC 60038)

System	V_LL (V)	V_LN (V)	Tolerance	Application
LT Standard	415	240	±6%	Industrial & commercial
LT (old)	400	231	±6%	Legacy installations
11 kV	11,000	6,351	±6%	Distribution feeder
22 kV	22,000	12,702	±6%	Sub-transmission
33 kV	33,000	19,053	±6%	Sub-transmission
66 kV	66,000	38,105	±5%	Transmission
110 kV	110,000	63,509	±5%	Transmission
220 kV	220,000	127,017	±5%	Transmission