2厂用电保护整定计算

阻抗换算：XL?X?L?Sujj2?0.069?0.14?5.66.32?0.00136

（5）厂用变压器41B、41B阻抗换算 厂用变压器参数

Sj——560/10， ud%=7.47% 阻抗换算：XB?0.0477?5600560?0.747

4.画出残压计算标呢电抗图（图7-2） 5.残压计算

（1）6KVI段全部自启动 6KVI段母线残压

ue?(4.5?0.747)?0.754.5?0.747?0.75?(4.5?0.747)?0.753.9355.9973.9355.997?0.0624.5?0.747?0.75??(0.061?0.00136)0.6560.656?0.0620.6560.718

????0.913

uc=91.3%

380VI段母线残压：uc??4.50.747?4.54.55.247?91.3%

?913%?0.857?91.3%?78.2%

（2））6KVII段全部自启动 6KVII段母线残压

ue?(4.5?0.747)?0.7124.5?0.747?0.712?(4.5?0.747)?0.7123.7355.9593.7355.959?0.062?4.5?0.747?0.712??(0.061?0.00136)0.6260.626?0.0620.6260.668

???0.909

uc=91.3%

4.50.747?4.54.55.247?90.9%

380VI段母线残压：uc???90.9%?0.857?90.9%?77.9%

（3）6KVI、II段同时自启动

6KVI、II段综合电抗

x?I?II?0.6560.626?0.656?0.6260.656?0.626?0.411.282?0.32

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6KVI、II段残压ue?4.50.747?4.5?83.7%

?0.857?83.7%?71.73%

根据上述计算，6KV残压83.7＞65；380V残压71.73＞55，显然残压计算是合格的。 、1-10。

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