免费功率因数计算器
计算交流电路的功率因数和无功功率。
Power Factor
0.833
Power Factor vs Real Power (P)
公式
## Power Factor Power factor indicates how effectively electrical power is being converted to useful work. ### Formulas **PF = P / S = kW / kVA** **Q = sqrt(S^2 - P^2)** A power factor of 1.0 means all power is real (useful). Low power factor means more current flows than needed, increasing losses. Industrial facilities typically aim for PF > 0.95 to avoid utility penalties.
计算示例
A facility drawing 30 kVA with 25 kW real power.
- 01PF = 25 / 30 = 0.833
- 02Q = sqrt(30^2 - 25^2) = sqrt(900 - 625) = sqrt(275) = 16.58 kVAR
- 03Phase angle = arccos(0.833) = 33.6 degrees
常见问题
What causes low power factor?
Induction motors (especially when lightly loaded), transformers, fluorescent lighting ballasts, and welding equipment all draw reactive current that lowers power factor. Heavily loaded motors have better PF than lightly loaded ones.
How do I improve power factor?
Install capacitor banks to offset reactive power, use synchronous condensers, replace lightly loaded motors with properly sized ones, or use active power factor correction (PFC) on electronic loads.
What is the penalty for low power factor?
Most utilities penalise facilities with PF below 0.9 or 0.85. Penalties can range from 1% to 15% of the electrical bill. Additionally, poor PF wastes energy in conductors due to higher I^2R losses.
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