免费电容器组计算器
计算功率因数补偿所需的电容器组容量。
Required Capacitor Bank
110.6 kVAR
Required Capacitor Bank vs Real Power (P)
公式
## Power Factor Correction with Capacitors Capacitor banks supply reactive power locally, reducing the reactive current drawn from the supply. ### Formula **Q_c = P (tan(phi_1) - tan(phi_2))** where P is real power, phi_1 = arccos(PF_old), phi_2 = arccos(PF_new). Equivalently: tan(phi) = sqrt(1/PF^2 - 1).
计算示例
Improve power factor from 0.75 to 0.95 on a 200 kW load.
- 01tan(phi_1) = sqrt(1/0.75^2 - 1) = sqrt(0.778) = 0.882
- 02tan(phi_2) = sqrt(1/0.95^2 - 1) = sqrt(0.108) = 0.329
- 03Q_c = 200 x (0.882 - 0.329) = 200 x 0.553 = 110.6 kVAR
- 04Select 120 kVAR capacitor bank (next standard size).
常见问题
Should I correct to unity power factor?
Generally no. Correcting to exactly 1.0 is expensive and can cause leading power factor during light load conditions, which may create voltage rise issues. Target 0.92-0.97 for best economics.
What types of capacitor banks are available?
Fixed banks provide constant correction. Automatic (switched) banks use a controller to switch capacitor stages in and out as load varies. Automatic banks are preferred for varying loads to avoid over-correction.
Can capacitors cause harmonic problems?
Yes. Capacitors can resonate with system inductance at harmonic frequencies, amplifying harmonics. In systems with significant harmonic content (VFDs, rectifiers), use detuned capacitor banks with series reactors.
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