某通用机器厂供配电系统设计

摘要

本论文主要是对小型工厂供配电系统的电气部分进行设计。工厂由户外引入10kV的高压电源，经过工厂变电所降为220/380V的低压电，直接供给工厂车间的动力系统和照明系统。

在选择电气设备之前，先对工厂负荷进行计算，确定工厂总的负荷容量，同时在低压母线侧进行无功功率的补偿，以提高功率因数。根据补偿后的负荷容量，选择工厂变电所变压器的容量和台数，然后确定工厂采用的供电系统，选择合适的车间配电方案，画出供配电系统主接线图。

高压一次设备、低压一次设备和导线截面积选择时，都必须满足电路正常条件下和短路故障条件下工作的要求。电气设备不仅要满足在短路故障条件下的工作要求，还必须按最大可能的短路故障时的动稳态度和热稳态度进行校验，以判断设备是否满足工作要求。电路发生三相短路时的短路电流电流最大，计算三相短路电流，以进行设备的校验。

最后，进行继电保护和防雷接地，来提高系统的安全性和可靠性。

关键词：负荷计算，三相短路，主接线，继电保护，设备选择

Abstract

This thesis is mainly on the small plant power supply and distribution system of the electrical part design. The factory introduced by10kV outdoor high voltage power plant substation, after falling to 220/ 380V low voltage, direct supply factory workshop power system and lighting system.

In the selection of electrical equipment, first on the factory load calculation, to determine the total factory load capacity, at the same time in the low voltage side of the reactive power compensation, in order to improve the power factor. According to the compensated load capacity, plant selection of substation transformer capacity and numbers, and then determine the factory uses the power supply system, select the appropriate workshops distribution scheme, draw the main wiring diagram of power supply and distribution system.

High voltage primary equipment, low-pressure primary equipment and wire cross-sectional area selection, must meet the circuit under normal conditions and under fault conditions work requirements. Electrical equipment not only to meet the short circuit fault under the conditions of the job requirements, according to the maximum possible short-circuit fault of the dynamic stability and heat stability check attitude to determine whether the equipment meet the job requirements. Circuit of three-phase short-circuit current at maximum current, calculation of three-phase short-circuit current, for equipment calibration.

Finally, for relay protection and lightning protection and grounding, to enhance the security and reliability of system.

Key words:distribution, load calculation, the three-phase short circuit, relay protection

目录

摘要 ........................................................................ I Abstract ................................................................... II 目录 ...................................................................... III

1 绪论 (1)

2 电力负荷及其计算 (2)

2.1 负荷分级及供电电源措施 (2)

2.1.1 工厂电力负荷的分级 (2)

2.1.2 各级负荷的供电措施 (2)

2.2工厂计算负荷的确定 (3)

2.2.1负荷计算的目的和意义 (3)

2.2.2负荷计算的方法 (3)

2.2.3需要系数法确定计算负荷 (4)

2.2.4二项式法确定计算负荷 (6)

2.2.5工厂负荷的计算 (6)

2.3无功功率补偿 (9)

2.3.1功率因数 (9)

2.3.2无功补偿的选择 (10)

2.3.3无功补偿的计算 (11)

3 变压器的选择及其电气主接线 (13)

3.1变压器的选择 (13)

3.1.1电力变压器及其分类 (13)

3.1.2电力变压器的连接组别 (13)

3.1.3变压器台数和容量的选择 (14)

3.1.4电力变压器的校验 (15)

3.2工厂变配电所的主接线图 (15)

3.2.1电气主接线的概况 (15)

3.2.2车间和小型工厂变电所的主接线图 (16)

3.2.3本工厂变电所主接线的确定 (21)

4 短路电流的计算 (22)

4.1短路的原因、后果及其形式 (22)

4.1.1短路的原因 (22)

4.1.2短路的后果 (22)

4.1.3短路的形式 (23)

4.2无限大容量电力系统的三相短路计算 (23)

4.2.1无限大容量电力系统 (23)

4.2.2短路电流的计算方法 (23)

4.2.3工厂三相短路电流的计算 (25)

第5章金工车间的配电 (28)

5.1低压配电线路接线方式 (28)

5.2低压配电系统的接地型式 (29)

第6章设备选择与校验 (33)

6.1导线的选择与校验 (33)