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⚡ 功率因数计算器Power Factor Calculator
由有功功率和视在功率，或由有功功率、电压和电流（单相或三相）计算功率因数 cos φ、相位角、无功功率，并估算提高到目标功率因数所需的补偿电容无功容量。Find the power factor cos φ, phase angle and reactive power from real and apparent power, or from real power, voltage and current (single- or three-phase) — and the capacitor kvar needed to correct to a target power factor.
使用说明与常见问题How-to & FAQ
「功率因数计算器」是什么？What is the Power Factor Calculator tool?
由有功功率和视在功率，或由有功功率、电压和电流（单相或三相）计算功率因数 cos φ、相位角、无功功率，并估算提高到目标功率因数所需的补偿电容无功容量。Find the power factor cos φ, phase angle and reactive power from real and apparent power, or from real power, voltage and current (single- or three-phase) — and the capacitor kvar needed to correct to a target power factor.
如何使用「功率因数计算器」？How do I use the Power Factor Calculator tool?
在「功率因数计算器」中，填写「已知条件」、「有功功率 P（kW）」、「视在功率 S（kVA）」、「电压 V（V）」、「电流 I（A）」等参数，结果会随输入实时计算并显示在下方。In the Power Factor Calculator: Fill in "Known values", "Real power P (kW)", "Apparent power S (kVA)", "Voltage V (V)", "Current I (A)"; results are recalculated instantly as you type.
功率因数怎么算？How is power factor calculated?
功率因数 PF = 有功功率 P ÷ 视在功率 S = cos φ。单相 S = V × I，三相 S = √3 × 线电压 × 线电流。无功功率 Q = √(S² − P²)。例如 P = 10 kW、S = 12.5 kVA，PF = 0.8，Q = 7.5 kvar。Power factor PF = real power P ÷ apparent power S = cos φ. Single-phase S = V × I; three-phase S = √3 × line voltage × line current. Reactive power Q = √(S² − P²). With P = 10 kW and S = 12.5 kVA, PF = 0.8 and Q = 7.5 kvar.
补偿电容量怎么估算？How is the correction estimated?
所需电容无功 Qc = P × (tan φ₁ − tan φ₂)，φ₁ 是当前相位角，φ₂ = arccos(目标功率因数)。默认例子从 0.8 提高到 0.95 需要约 4.21 kvar，视在功率从 12.5 kVA 降到约 10.53 kVA。The capacitor kvar is Qc = P × (tan φ₁ − tan φ₂), with φ₁ the present phase angle and φ₂ = arccos(target PF). Raising the default example from 0.8 to 0.95 needs about 4.21 kvar and cuts the apparent power from 12.5 kVA to about 10.53 kVA.
有什么限制？What are the limits?
假设正弦波形，不考虑谐波造成的畸变功率因数；补偿按感性负载计算。实际选型请参考设备铭牌和电气规范。It assumes sinusoidal waveforms and ignores distortion power factor from harmonics; correction assumes an inductive load. For real equipment sizing, follow nameplate data and electrical codes.
计算结果可以用于作业或工程吗？Can I use the results for homework or engineering?
「功率因数计算器」使用教科书标准公式（公式写在说明和常见问题中），适合学习和估算核对；涉及安全的工程设计请以规范和实测为准。The Power Factor Calculator uses standard textbook formulas (given in the description and FAQ), which is good for learning and checking estimates; for safety-critical engineering follow codes and measured values.
「功率因数计算器」免费吗？需要注册吗？Is the Power Factor Calculator free? Do I need an account?
「功率因数计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Power Factor Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.