发电机电流计算器
根据发电机的 kVA 求出满载电流和故障电流。
尝试一个工程 5
每项工作都会预填示例数值。请替换为您自己的数值。
- Check a 60 kVA standby generatorThe full load current and the fault current of a 60 kVA set at 400 V.
- Check a 200 kVA generatorThe full load current of a 200 kVA set at 400 V.
- Check a portable generatorThe current of a 10 kVA single‑phase set.
- Find a generator's fault currentThe fault current of a 500 kVA set at 15 % reactance.
- Check a holiday park backup setThe current and fault level of a 150 kVA set.
输入
使用默认输入值的示例计算。
- 额定值
- 100 kVA
- 相
- 三相
- 电压
- 400 V
- 功率因数
- 0.8
- 次暂态电抗
- 15 %
满载电流
144.34A
- 有功功率
- 80kW
- 故障电流
- 962.25A
此结果仅供设计参考。请对照现行标准进行核验。
计算步骤
- 满载电流结果144.34A
- 有功功率80kW
- 故障电流962.25A
关于此计算器
How this is calculated
The tool works from the kVA rating on the generator nameplate. It gives the full load current, the real power and the fault current at the terminals. The steps are plain circuit arithmetic. The tool reads no Standard table.
- Apparent power. You enter the rating in kVA. The tool converts it to VA.
- Full load current. On three phases the tool divides the VA by √3 times the line voltage. On one phase it divides by the voltage.
- Real power. It multiplies the kVA by the power factor you enter. The result is in kW.
- Fault current. It divides the full load current by the subtransient reactance, as a fraction. This is the first-cycle symmetrical value.
| Step | Basis | What it decides |
|---|---|---|
| Full load current | I = S / (√3 × V) | The current at rated output |
| Real power | P = S × power factor | The load the engine must drive |
| Fault current | I / X″d | The first-cycle fault level at the terminals |
Worked example
A 200 kVA set at 400 V on three phases has a power factor of 0.8. Its subtransient reactance is 15 %. The full load current is 288.68 A. The real power is 160 kW. The fault current is 1,924.5 A.
Limits
- The fault current is the initial symmetrical value only. It ignores the decay to the transient and synchronous values.
- It ignores any excitation limit. A few cycles in, the real current is much lower.
- The tool does not size the generator for motor starting or step loads.
- It does not size the cable or the protective device. Use the cable size calculator for the cable.
- The subtransient reactance comes from the maker data sheet. No default fits every set.
See also: Generator fault current from the subtransient reactance, Generator full load current from kVA and the fault level calculator.
问题
结果仅供设计参考。请依据现行标准核对。
发电机计算器有什么作用？
工具报告交流发电机的满载电流、有功功率输出及故障电流。它以千伏安额定值、电压、相数、功率因数和次暂态电抗为输入。
哪些输入最重要？
额定值和电压决定满载电流。功率因数决定以千瓦计的有功功率。次暂态电抗决定故障电流，工具中的默认值为 15%。电抗越低，故障电流越大。
常见的注意事项有哪些？
故障电流为初始次暂态值，取满载电流除以标幺电抗。如有电机测试单数值，请使用该数值。未计入电缆阻抗。输入值保存在页面地址中，因此链接可重现该结果。
计算示例
- Generator fault current calculation at 400 VA 500 kVA 400 V standby set at 12 % subtransient reactance gives 721.69 A full load and 6014.07 A fault current, with the decay the figure leaves out.
- What size generator for a dairy shedSize a standby set for a dairy shed from its load list. The vacuum pump's start sets the size, then staggered steps, a drive and a soft starter shrink it.
- Generator full load current: 200 kVA to ampsA 200 kVA 400 V standby set converted to 288.68 A of full load current, 160 kW of real power and 2,405.63 A of initial fault current from 12 % reactance.
- Generator sizing for a 150 kVA holiday parkA 150 kVA three‑phase standby set at 400 V gives 216.51 A full load current, 120 kW real power and 1443.38 A fault current from one nameplate.
背景
相关工具
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