最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

完全毕业设计（论文） 某厂总降压变电所及厂区配电系统设计

2012 年 5 月

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

湖南工业大学科技学院毕业设计（论文）

某厂总降压变电所及厂区配电系统设计

20 12 年 5 月

摘 要

众所周知，电能是现代工业生产的主要能源和动力。供电系统就像工厂的心脏，对工厂的运行有着至关重要的作用。

根据变电所配电回路，负荷要求的可靠性级别和计算负荷综合主变压器台数，确定变电所高、低接线方式。一般10KV及以下高压线路及低压动力线路，通常先按发热条件来选择截面，再校验电压损耗和机械强度。

此外还需要注意防雷接地等安全措施，保证供电系统的正常运行。

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

目 录

第1章 负荷计算和无功功率补偿····························································· 1

1.1负荷计算 ······················································································································ 1 1.1.1负荷计算的目的及方法 ······························································································· 1 1.1.2各车间的负荷计算 ······································································································· 1 1.2无功功率补偿及其计算 ·············································································································· 10

第2章 供电方案的设计 ·············································································· 12

2.1变电所位置和型式的选择 ········································································································· 12 2.1.1变配电所位置选择的要求 ························································································ 12 2.1.2高压线路的接线方式 ································································································· 12 2.2变电所主接线的选择 ··················································································································· 12 2.2.1 对工厂变电所主接线的要求 ··················································································· 12 2.2.2 工厂总降压变电所常见的主接线方案 ·································································· 13 2.2.3 变电所主接线的选择 ································································································ 15

第3章 变电所主变压器台数及容量的选择 ··············································· 16

3.1变压器选择的原则 ························································································································ 16

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

3.1.1 变电所主变压器台数的选择原则 ··········································································· 16 3.1.2 变电所主变压器容量的选择 ··················································································· 16 3.2 电力变压器的选择 ······················································································································· 17 3.2.1 35KV主变压器的选择 ······························································································ 17 3.2.2 6KV车间变压器的选择 ······························································································ 17

第4章 短路电流及其计算 ············································································ 1

4.1 短路计算的目的及其计算方法 ·································································································· 1 4.1.1 短路计算的目的 ··········································································································· 1 4.1.2 短路的危害 ···················································································································· 1 4.1.3 短路电流计算方法 ······································································································· 2 4.2 短路电流计算 ···································································································································· 2

第5章 导线及截面积的选择 ········································································ 1

5.1 导线和电缆截面积得选择与校验 ····························································································· 1 5.2 工厂电力线路的选择与校验 ······································································································· 1 5.2.1 35KV架空线的选择 ······································································································ 1 5.2.2 6KV母线的选择 ············································································································· 2 5.2.3 6KV配电线路的选择 ···································································································· 2

第6章 电气设备的选择与校验 ···································································· 1

6.1 电气设备的校验项目及方法 ······································································································· 1 6.1.1 电气设备选择及检验的一般原则 ············································································· 1 6.1.2 高压设备的选择校验项目和条件 ············································································· 2 6.2 工厂35KV高压电气设备的选择 ································································································ 3 6.2.1 高压开关柜的选择 ······································································································· 3 6.2.2 断路器的选择与校验 ·································································································· 3 6.2.3 隔离开关的选择校验 ·································································································· 4 6.2.4 熔断器的选择与校验 ·································································································· 4 6.2.5 电流互感器的选择与校验 ·························································································· 5 6.2.6 电压互感器的选择与校验 ·························································································· 6 6.2.7 过电压与防雷················································································································ 7 6.3 6KV高压电气设备的选择 ············································································································· 7 6.3.1 高压开关柜的选择 ······································································································· 7 6.3.2 断路器的选择与校验 ·································································································· 8 6.3.3 隔离开关的选择与校验 ······························································································ 8 6.3.4 熔断器的选择·············································································································· 39

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

6.3.5 电流互感器的选择 ····································································································· 39 6.3.6 电压互感器的选择 ····································································································· 10 6.3.7 避雷措施及避雷器的选择 ························································································ 10

第7章 总降压变电所继电保护设计··························································· 11

7.1 继电保护的任务和要求···············································································································11 7.1.1 继电保护的任务 ········································································································· 11 7.1.2 继电保护的基本要求 ································································································ 11 7.2 工厂高压线路的继电保护 ········································································································· 12 7.2.1 高压线路的继电保护 ································································································ 12 7.2.2动作电流及动作时限的整定 ···················································································· 12 7.3 电力变压器的继电保护·············································································································· 13 7.3.1 过电流保护 ·················································································································· 14 7.3.2 电流速断保护·············································································································· 14 7.3.3 瓦斯保护 ······················································································································ 15

第8章 总降压变电所接地与防雷设计 ······················································· 16

8.1防雷设计 ··········································································································································· 16 8.2变电所的防雷措施 ························································································································ 16 8.2.1装设避雷针··················································································································· 16 8.2.2高压侧装设避雷器 ····································································································· 17 8.2.3低压侧装设避雷器 ····································································································· 17 8.3接地设计 ··········································································································································· 18 8.3.1接地的类型··················································································································· 18 8.3.2 电力设备接地基本要求 ···························································································· 18

结论 ··············································································································· 49 参考文献 ········································································ 错误！未定义书签。 致谢 ················································································ 错误！未定义书签。 附录 ················································································ 错误！未定义书签。

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

第1章 负荷计算和无功功率补偿

1.1负荷计算

1.1.1负荷计算的目的及方法

负荷计算是供电系统设计的基础，其主要目的是确定“计算负荷”。“计算负荷”是按照发热条件选择电气设备的一个假象持续负荷，“计算负荷”产生的热效应和实际变动负荷产生的最大热效应相等。它是选择供电系统变压器，导线以及开关等电气设备的依据。

计算负荷是确定供电系统、选择变压器容量、电气设备、导线截面和仪表量程的依据，也是整定继电保护的重要数据。企业进行电力设计的原始资料是工艺部门提供的用电设备的安装容量，这些用电设备品种多，数量大，工作情况复杂。估算的准确程度，影响工厂的电力设计质量，估算过高，会增加供电设备的容量，使工厂电网复杂，浪费有色金属，增加初投资和运行管理工作量。工厂电力需用量是国家电力系统建设的基础，如果使用不合理将给国民经济建设带来很大的危害。如估算过低，又会使工厂投入生产后，供电系统的线路及电气设备由于承担不了实际电流而过热，如加速绝缘老化的速度，降低使用寿命，增大电能损耗：甚至烧毁，以致安全事故，影响供电系统的正确可靠运行，给国家造成损失。

确定全厂的计算负荷的方法很多，目前最常用是的需要系数法，即先从用电端求逐级起往电源方向计算，首先按照需要系数法求得各车间低压侧有功及无功计算负荷，加上本车间变电所的变压器有功及无功功率损耗，即得车间变电所高压侧的计算负荷。需求常数法比较简便。

其次是二项式法，二项式法也比较简便，它考虑了事数台大功率设备工作时对负荷影响的附加功率。但计算结果往往偏大，一般用于低压配电支干线和配电箱的负荷计算。

1.1.2各车间的负荷计算

（1） NO.1车变

1）380V低压侧计算负荷

铸钢车间： P30 KdPe 0.45 2200kW 990kW

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

Q

30

P

30

tan 990kW 0.88 871.20kvar

30

S30

cos

990kW

1320kVA

0.75

I30

U

30

N

1320kVA 0.38kV

2005.53A

2）变压器的功率损耗

PT 0.015S30 0.015 1320kVA 19.80kW Q 0.06S30 0.06 1320kVA 79.20kvar

T

3）高压侧(6kV)计算负荷

P30 p

'

'

30

PT 990kW 19.8kW 1009.80kW Q 817.2kvar 79.2kvar 896.40kvar

T

Q30 Q

S30

'

'

30

P30

'

Q

2

30

'

2

.8

2

896.4 1350.27kVA

2

I30

UN

'

1350.27kVA3 6kV

129.93A

（2） NO.2车变

1）380V低压侧计算负荷

铸铁车间: P30 1 KdPe 0.45 1500kW 675kW

Q

30 1

P

P

30 1

tan 675kW 1.02 688.50kvar 675kW

983.57kVA

0.70

S30 1

30 1

cos

I30 1 Q

S 3U

301

983.57kVA 0.38kV

1494.38A

N

砂库： P30 2 KdPe 0.7 200kW 140kW

30 2

P

P

30 2

tan 140kW 1.17 163.80kvar 140kW

215.38kVA

0.65

S30 2

30 2

cos

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

I30 2

S

30 2

3UN

215.38kVA 0.38kV

327.24A

取K p 0.9,K q 0.9 所以 P30 K p

P

30 1

P30 2 0.9 675 140 733.5kW Q

2

30 2

Q

30

K Q

q

30 1

0.9 688.5 163.8 767.07kvar

2

S30

I30

P30 Q30 U

30

2

733.5 767.07 1061.33kVA

2

N

1061.33kVA3 0.38kV

1612.52A

2）变压器的功率损耗

PT 0.015S30 0.015 1061.33kVA 15.92kW Q 0.06S30 0.06 1061.33kVA 63.68kvar

T

3）高压侧(6kV)计算负荷

P30 p

Q30 Q

'

'

30

PT 733.5kW 15.92kW 749.42kW

T

30

Q 767.07kvar 63.68kvar 830.75kvar

S30

'

'

P30

'

Q

2

30

'

2

749.42

2

830.75 1118.83kVA

2

30

I30

UN

（3）NO.3车变

1）380V低压侧计算负荷 铆焊车间:

S

'

1118.83kVA 6kV

106.99A

P

30 1

30 1

KdPe 0.35 1400kW 490kW

Q

P

30 1

tan 490kW 1.52 744.8kvar

S30 1

P

30 1

cos

490kW

890.91kVA

0.55

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

I30 1

S 3U

301

890.91kVA3 0.38kV

1353.60A

N

1#水泵房：

P

30 2

KdPe 0.7 50kW 35kW

Q

30 2

P

30 2

tan 35kW 0.75 26.25kvar

S30 2

P

30 2

cos

35kW

43.75kVA

0.80

I30 2 P

S

30 2

UN

43.75kVA3 0.38kV

66.47A

取K p 0.9,K q 0.9 所以

30

K p

q

Q

30

K Q

2

P

30 1

P30 2 0.9 490 35 472.5kW

30 2

30 1

Q

2

0.9 744.8 26.25 693.95kvar

2

S30

P30 Q30

472.5 693.95 839.54kVA

2

I30

U

30

N

839.54kVA 0.38kV

1275.55A

2）变压器的功率损耗

PT 0.015S30 0.015 839.54kVA 12.59kW Q 0.06S30 0.06 839.54kVA 50.37kvar

T

3）高压侧(6kV)计算负荷

P30 p

'

'

30

PT 472.5kW 12.59kW 485.09kW Q 693.95kvar 50.37kvar 744.32kvar

T

Q30 Q

30

S30

'

'

P30

'

Q

2

30

'

2

485.09

2

744.32 888.44kVA

2

I30

UN

'

888.44kVA3 6kV

85.49A

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

（4） NO.4车变

1）380V低压侧计算负荷 空压站:

P

30 1

KdPe 0.8 420kW 336kW

Q

30 1

PP

30 1

tan 336kW 0.88 295.68kvar 336kW

448kVA S30 1

30 1

机修车间：

锻造车间： 木型车间： 制材厂： cos

0.75

I S30 1

448kVA30 1

N

0.38kV

680.67A

P30 2 KdPe 0.35 180kW 63kW

Q

30 2

P

30 2

tan 63kW 1.02 64.26kvar SP

30 2

63kW

30 2

cos

0.7

90kVA I90kVA30 2 S

30 2

3U

N

3 0.38kV

136.74A

P30 3 KdPe 0.35 200kW 70kW

Q

30 3

P

30 3

tan 70kW 0.88 61.6kvar

S30 3

70kW

30 3

P

cos

0.75

93.33kVA IS

30 3

93.33kVA30 3 U

N

3 0.38kV

141.81A

P30 4 KdPe 0.45 1600kW 720kW

Q

30 4

P

30 4

tan 720kW 0.88 633.6kvar

S720kW

30 4

P

30 4

cos

0.75

960kVA

IS

30 4

30 4 U

960kVAN

3 0.38kV

1458.57A

P30 5 KdPe 0.35 35kW 12.25kW

Q

30 5

P

30 5

tan 12.25kW 1.17 14.33kvar

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

S30 5

P

30 5

cos

12.25kW

18.85kVA

0.65

I30 5 Q

S

30 5

UN

18.85kVA 0.38kV

28.64A

综合场： P30 6 KdPe 0.90 35kW 31.50kW

30 6

P

P

30 6

tan 31.5kW 0 0kvar 31.5kW

31.50kVA

1.00

S30 6

30 6

cos

I30 6

S

30 6

3UN

31.50kVA3 0.38kV

47.86A

取K p 0.5,K q 0.5 所以 P30 K p

P

30 1

P30 2 P30 3 P30 4 P30 5 P30 6

0.5 336 63 70 720 12.25 31.5 616.38kW

Q

30

K q

Q

30 1

Q

30 2

Q

30 3

Q

30 4

Q

30 5

Q

30 6

0.5 295.68 64.26 61.6 633.6 14.33 0 534.74kvar

S30

'

P30

'

Q

2

30

'

2

616.38

2

534.74 816.01kVA

2

I30

U

30

N

816.01kVA3 0.38kV

1239.80A

2）变压器的功率损耗

PT 0.015S30 0.015 816.01kVA 12.24kW Q 0.06S30 0.06 816.01kVA 48.96kvar

T

3）高压侧(6kV)计算负荷

P30 p

'

30

PT 616.38kW 12.24kW 628.62kW

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

Q30 Q

S

30

'

'

'

30

Q 534.74kvar 48.96kvar 583.7kvar

T

P30

'

Q

2

30

'

2

628.62 583.7

247.64A

22

857.83kVA

I303UN

'

857.83kVA 6kV

（5）NO.5车变

1）380V低压侧计算负荷

锅炉房: P30 1 KdPe 0.75 260kW 195kW

Q

30 1

P

30 1

tan 195W 0.75 146.25kvar 146.25kW

182.81kVA

0.80

S30 1

P

30 1

cos

I30 1 Q

S 3U

301

182.81kVA3 0.38kV

277.75A

N

2#水泵房： P30 2 KdPe 0.75 80kW 60kW

30 2

P

30 2

tan 60kW 0.75 45kvar

60kW

75kVA 0.80

S30 2

P

30 2

cos

I30 2

S

30 2

UN

75kVA3 0.38kV

113.95A

仓库（1，2）： P30 3 KdPe 0.3 75kW 22.5kW

Q30 3 P30 3 tan 70.4kW 1.17 82.37kvar

S30 3

P

30 3

cos

82.37kW

126.72kVA

0.65

I30 3 Q

S

30 3

3UN

126.72kVA 0.38kV

192.54A

污水提升站： P30 4 KdPe 0.65 20kW 13kW

30 4

P

30 4

tan 13kW 0.75 9.75kvar

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

S30 4

P

30 4

cos

13kW

16.25kVA 0.80

I30 4

取K p 0.5,K q 0.5

S

30 4

3UN

16.25kVA 0.38kV

24.69A

所以 P30 K p

P

30 1

P30 2 P30 3 P30 4

0.5 195 60 22.5 13 145.25kW

Q

30

K q

Q

30 1

Q

30 2

Q

30 3

Q

30 4

0.5 146.25 45 82.37 9.75 141.69kvar

S30

I30

P30 Q30 U

30

22

.25

2

141.69 202..91kVA

2

N

202.91kVA 0.38kV

308.30A

2）变压器的功率损耗

PT 0.015S30 0.015 202.91kVA 3.05kW Q 0.06S30 0.06 202.91kVA 12.20kvar

T

3）高压侧(6kV)计算负荷

P30

'

'

p

30

PT 145.25kW 3.05kW 148.30kW Q 141.69kvar 12.20kvar 153.89kvar

T

Q30 Q

S30

'

'

30

P30

'

Q

2

30

'

2

.30

20.57A

2

153.89 213.72kVA

2

I30 3

UN

'

213.72kVA 6kV

（6）高压设备计算负荷

电弧炉： P30 1 KdPe 0.90 2 1300kW 2340kW

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

Q

30 1

P

30 1

tan 2340kW 0.62 1450.80kvar

2340kW

2752.94kVA

0.85

S30 1

P

30 1

cos

I30 1 Q

S 3U

301

2752.94kVA 6kV

264.91A

N

工频炉： P30 2 KdPe 0.85 2 250kW 425kW

30 2

P

30 2

tan 425kW 0.48 191.25kvar

425kW

472.22kVA

0.90

S30 2

P

30 2

cos

I30 2 Q

S

30 2

3UN

472.22kVA 6kV

45.44A

空压机： P30 3 KdPe 0.8 2 280kW 448kW

30 3

P

30 3

tan 448kW 0.75 336kvar 448kW

560kVA 0.8

S30 3

P

30 3

cos

303

S 560kVA 53.89A 3U3 6kV

所以 P30 P30 1 P30 2 P30 3 2340 425 448 3213kW

Q Q Q Q 1450.8 192.25 336 1978.05kvar

I30 3

N

303013022

303

S30 I30 1

P30 Q30 S 3U

301

2

2

1978.05 3773.07kVA

2

3773.07kVA3 6kV

363.07A

N

（7）全厂总的计算负荷

取K p 0.92,K q 0.95，则35/6kV低压母线的计算负荷为： P30 K p P30.i

0.92 1009.8 733.5 485.09 628.62 148.3 3213

5720.85kW

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

Q K q Q

30

30.i

0.95 896.4 767.07 744.32 583.7 153.89 1978.05 4867.26kvar S30

P30 Q30 S

30

22

5720.85

2

4867.26 7517.05kVA

2

cos

30

5720.85

0.7610498799 0.76

7517.05

1.2无功功率补偿及其计算

按我国原电力工业部1996年颁布实施的《供电营业规则》规定: “用户应在提高用电自然功率因数的基础上，按有关标准设计和安装无功补偿设备，并做到随其负荷和电压变动及时的投入或切除，防止无功电力倒送。除电网有特殊要求的用户外，用户在当地供电企业规定的电网高峰负荷时的功率因数，应达到下列规定：100Kv及以上的高压供电用户，功率因数为0.9以上。其他电力用户和大、中型电力排灌站，功率因数为8.5以上。”因此工厂的功率因数达不到上述要求时，必须增设无功功率的人工补偿装置。

根据该工厂的实际设计要求，工厂采用高压集中补偿为主。该厂6kV侧最大负荷是的功率因数只有0.76。而供电部门要求该厂35kV进线侧最大负荷时功率因数不应低于0.9。考虑到主变电器的无功损耗远大于有功损耗，因此6kV侧最大负荷时功率因数应稍大于0.9，暂取0.93来计算6kV侧所需无功功率补偿容量：

'

tan tan Qc P30

5720.85kW tanarccos0.76 tanarccos0.93 5720.85kW 0.8361 0.3952 2522.32kvar

取Q 2522kvar，则

c

补偿后35/6kV变电所低压侧的计算负荷为: P30 5720.85kW

Q 4867.26 2522 2345.26kvar

30

S30

P30 Q30

22

5720.85

2

2345.26 6182.91kVA

2

最权威的铸造厂总降压变电所及厂区配电系统设计和毕业设计

I30

主变压器损耗:

U

30

N

6182.91kVA 6kV

594.96A

PT 0.015S30 0.015 6182.91kVA 92.74kW Q 0.06S30 0.06 6182.91kVA 370.97kvar

T

补偿后35/6kV高压侧计算负荷:

P30 p

'

'

30

PT 5720.85kW 92.74kW 5813.59kW Q 2345.26kvar 370.97kvar 2716.23kvar

T

Q30 Q

30

S30

'

P30

'

Q

2

30

'

2

.59

2

2716.23 6416.83kVA

2

cos

‘

Q30

'

''

5813.59kW

0.90599 0.91

6416.83kVA

I30 3

UN

'

S

6416.83kVA3 35kV

105.86A

因为采用并联电容器进行高压集中补偿。选用BWF6.3-100-1W型的电容器，其额定电容为2.89uF，Qc=2522.32kvar。

取Qc=2522kvar，因此其电容器的个数为：

n Qc

2522

25.22（个）

C

而由于电容器是单相的，所以应为3的倍数，即选取27个并联电容器。