山西煤销集团古县东瑞煤业有限公司
井 下 供 电 系 统 整 定 计 算 书
二零一二年七月
短路电流计算
1、电源系统电抗：取电源系统短路容量SS=50MVA
2Uav10.52XS???2.205?
SS50折算到660V侧
?Uav2XS?XS???U?av1??0.69???2.205????0.009522? ??10.5??222、架空线路阻抗：
宝丰至东瑞线：LGJ-240/30 钢芯铝绞线，4.286km 电抗：X?x0?L?0.369?4.286?1.582? 电阻：R?r0?L?0.130?4.286?0.5572? 折算到660V侧
?Uav2X?X???U?av1?Uav2R?R???U?av1??0.69???1.582????0.00683? ??10.5????0.69???0.5572????0.0024? ??10.5??22223、高压电缆阻抗：
高压电缆型号：MYJV42-3×70 电抗：X?x0?L?0.008?0.4?0.0032? 电阻：R?r0?L?0.307?0.4?0.1228? 折算到660V侧
?Uav2X?X???U?av1?Uav2R?R???U?av1
??0.69???0.0032????0.0001382? ??10.5????0.69???0.1228????0.0005303? ?10.5???1
2222
4、变压器电抗：
由变压器技术参数查表得KBSGZY-500变压器阻抗为：
XT?0.0427?
RT?0.0068?
由变压器技术参数查表得KBSGZY-630变压器阻抗为：
XT?0.0416?
RT?0.0056?
5、清煤斜巷最小短路电流计算：
（1）电缆MY-3×50共60m，电缆MY-3×25共150m 电缆MY-3×16共20m （2）低压电缆阻抗
X1?x0?L?0.081?0.06?0.00486? R1?r0?L?0.4484?0.06?0.026904? X2?x0?L?0.088?0.15?0.0132? R2?r0?L?0.8638?0.15?0.12957? X3?x0?L?0.09?0.02?0.0018? R3?r0?L?0.369?0.02?0.02738?
（3）短路点短路回路总阻抗
X??0.009522+0.00683+0.0001382+0.0427+0.00486+0.0132+0.0018=0.079ΩR??0.0024+0.0005303+0.0068+0.026904+0.12957+0.02738=0.1936Ω
X?X2?R2?0.0792?0.19362???=0.20906Ω
（4）短路电流计算
3IS?Uav3Z??6903?0.20906?1905.5A
2
2IS?Uav690??1650.2A 2Z2?0.20906?6、回风巷刷扩最小短路电流计算：
（1）电缆MY-3×70共400m，电缆MY-3×25共200m （2）低压电缆阻抗
X1?x0?L?0.078?0.4?0.0312? R1?r0?L?0.3151?0.4?0.12604? X2?x0?L?0.088?0.2?0.0176? R2?r0?L?0.8638?0.2?0.17276?
（3）短路点短路回路总阻抗
X??0.009522+0.00683+0.0001382+0.0427+0.0312+0.0176=0.1079Ω R??0.0024+0.0005303+0.0068+0.12604+0.17276= 0.30854Ω
X?X2?R2?0.10792?0.30854???2= 0.3269Ω
（4）短路电流计算
?3?IS?Uav3Z??6903?0.3269?1218.6A
?2?IS?Uav690??1055.3A
2Z?2?0.32697、1米皮带最小短路电流计算：
（1）电缆MY-3×50共200m，电缆MY-3×25共10m （2）低压电缆阻抗
X1?x0?L?0.081?0.2?0.0162? R1?r0?L?0.4484?0.2?0.08698? X2?x0?L?0.088?0.01?0.000886?
3
R2?r0?L?0.8638?0.01?0.008638?
（3）短路点短路回路总阻抗
X??0.009522+0.00683+0.0001382+0.0427+0.0162+0.000886=0.07615Ω R??0.0024+0.0005303+0.0068+0.08698+0.008638= 0.1081Ω
X?X2?R2?0.076152?0.10812= 0.1322Ω ???（4）短路电流计算
?3?IS?Uav3Z??6903?0.1322?3013.7A
?2?IS?Uav690??2609.9A 2Z2?0.1322?8、绕道刷扩最小短路电流计算：
（1）电缆MY-3×50共220m，电缆MY-3×35共150m
电缆MY-3×25共100m （2）低压电缆阻抗
X1?x0?L?0.081?0.22?0.01782? R1?r0?L?0.4484?0.22?0.098648? X2?x0?L?0.084?0.15?0.0126? R2?r0?L?0.616?0.15?0.0924? X3?x0?L?0.088?0.1?0.0088? R3?r0?L?0.8638?0.1?0.08638?
（3）短路点短路回路总阻抗
X??0.009522+0.00683+0.0001382+0.0427+0.01782+0.0126+0.0088=0.09842ΩR??0.0024+0.0005303+0.0068+0.098648+0.0924+0.08638=0.287158Ω
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井下短路电流计算
