短路电流计算器

使用此短路电流计算器快速获得准确的计算结果。

kW

Required Capacitor Bank

55.3 kVAR

Current Reactive Power88.2 kVAR
New Reactive Power32.9 kVAR
Apparent Power Reduction28.1 kVA

Required Capacitor Bank vs Real Power

公式

Power Factor Correction

Low power factor means the utility must deliver more current (and apparent power) than the load actually uses. Capacitor banks supply reactive power locally.

Formula

kVAR needed = kW x (tan(arccos(PF_current)) - tan(arccos(PF_target)))

Benefits

  • Reduced utility power factor penalties
  • Lower line current (smaller cables, less loss)
  • Freed transformer and distribution capacity
  • Most utilities penalize power factors below 0.90. Correcting to 0.95 is a common economic target.

    计算示例

    100 kW load at PF 0.75, correcting to PF 0.95.

    1. 01Current angle: arccos(0.75) = 41.41 degrees, tan = 0.8819
    2. 02Target angle: arccos(0.95) = 18.19 degrees, tan = 0.3287
    3. 03kVAR needed: 100 x (0.8819 - 0.3287) = 55.3 kVAR
    4. 04kVA reduction: 100/0.75 - 100/0.95 = 133.3 - 105.3 = 28.1 kVA

    常见问题

    What causes low power factor?

    Inductive loads like motors, transformers, and fluorescent lighting draw reactive current that lags voltage, reducing power factor.

    Can I overcorrect power factor?

    Yes. A leading power factor (above 1.0 correction) can cause voltage rise and resonance. Do not exceed PF 0.98-0.99.

    Where should capacitors be installed?

    At the load for maximum benefit, at the main bus for simplicity, or a combination. Automatic switching banks handle varying loads.

    学习

    Ohm's Law Guide

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