三相功率计算器 — 公式
## Three-Phase Power Calculations
Three-phase systems are the standard for industrial power distribution.
### Formulas
**P = sqrt(3) x V_LL x I x cos(phi)** (real power in watts)
**S = sqrt(3) x V_LL x I** (apparent power in VA)
**Q = sqrt(3) x V_LL x I x sin(phi)** (reactive power in VAR)
where V_LL is the line-to-line voltage, I is the line current, and cos(phi) is the power factor. These apply to balanced loads.
Three-phase systems are the standard for industrial power distribution.
### Formulas
**P = sqrt(3) x V_LL x I x cos(phi)** (real power in watts)
**S = sqrt(3) x V_LL x I** (apparent power in VA)
**Q = sqrt(3) x V_LL x I x sin(phi)** (reactive power in VAR)
where V_LL is the line-to-line voltage, I is the line current, and cos(phi) is the power factor. These apply to balanced loads.
计算示例
A 400 V three-phase supply with 50 A line current at 0.85 power factor.
- S = sqrt(3) x 400 x 50 = 34,641 VA = 34.64 kVA
- P = 34,641 x 0.85 = 29,445 W = 29.44 kW
- Q = 34,641 x sin(acos(0.85)) = 34,641 x 0.5268 = 18.25 kVAR