电缆载流量计算器
使用此电缆载流量计算器快速获得准确的计算结果。
Real Power
14.13 kW
Real Power vs Line-to-Line Voltage
公式
Three-Phase Power Calculations
Three-phase systems are the standard for industrial and commercial power distribution.
Formulas (Balanced Load)
Apparent Power = sqrt(3) x V_line x I_line
Real Power = Apparent x Power Factor
Reactive Power = sqrt(Apparent^2 - Real^2)
Phase Voltage = Line Voltage / sqrt(3)
The sqrt(3) factor (approximately 1.732) arises from the 120-degree phase separation between the three phases.
计算示例
480 V three-phase, 20 A line current, 0.85 power factor.
- 01Apparent: sqrt(3) x 480 x 20 = 16,627 VA = 16.63 kVA
- 02Real: 16,627 x 0.85 = 14,133 W = 14.13 kW
- 03Reactive: sqrt(16627^2 - 14133^2) = 8,744 VAR = 8.74 kVAR
- 04Phase voltage: 480 / 1.732 = 277.1 V
常见问题
When is three-phase power used?
For loads above about 5 kW, large motors, industrial equipment, and commercial buildings. It provides constant power delivery and efficient motor operation.
What is the difference between line and phase values?
Line values are measured between phases (L-L). Phase values are measured from one phase to neutral. V_line = sqrt(3) x V_phase for wye connections.
What if the load is unbalanced?
These formulas assume balanced loads. For unbalanced loads, calculate each phase separately and sum the results.
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