电力网的线电压是380V,三相异步电动机每相绕组的额定电压是220V,则定子绕组必须采用______连接.

1.接地下引线
用于将雷电流从接闪器传导至接地装置的导体,或者简单理解为连接避雷带或者避雷针与接地主网相连的导体
2.接地体
埋入土壤中或混凝土基础中作散流用的导体,简单理解为就是水平接地极与垂直接地极（经常用扁钢作接地网,也就是接地体,接地体有扁钢、铜线、铜包钢绞线）
3.连接端
从引下线断接卡或换线处至接地体的位置；或从接地端子、等电位连接带至接地体的位置.
整个电力接地系统由这些部分组成.

图呢?

Minimum spanning tree network optimization is an important concept that the transportation network , power grids , telephone networks, such as the design of pipeline networks are widely used , this paper outlines the minimum spanning tree of related concepts , including map and tree and the minimum spanning some definitions and theorems for the next step to provide a theoretical basis for the minimum spanning tree and then describes the method for finding the minimum spanning tree of several , including the avoidance circle method and segmentation method , as well as other practical algorithms for future practical application of the foundation in practical applications , we use nature of the minimum spanning tree , using a segmentation method to obtain the mine ventilation system the minimum spanning tree , and finally completed the mine ventilation system design and elaborated in practical applications select the differences and corresponding method of minimum spanning tree and the shortest path in terms of the minimum spanning tree expansion , the paper discusses the impact of the original will modify the minimum spanning tree , such as increased side or deleted , while the weights modified. changes in the minimum spanning tree spanning restrictions on the conditions corresponding slightly involved . learning through the minimum spanning tree , it can be applied to higher costs in infrastructure .

看了楼上,我觉得自己以后没准也能拿这个当副业玩玩~
----------------------------------
Course description:
This course presents the foundations of electric power systems analysis after an initial review of single and three-phase power, complex power and transformers. Topics include per unit quantities, generators, transmission line models, transformer models, short-circuit analysis, load flow, and power systems economics.
Course main content:
1.Review of power system networks, complex power, and per units
2.Generator, load, transformer, and line models
3. Network matrices, Power flow techniques- solving by the Gauss-Seidel method, by the Newton-Raphson method
4.Fault studies: bus-impedance matrix , Symmetrical components and the sequence impedances ,Synchronous machine dynamics and the swing equation

线路传输的稳定极限功率.由于电网联络线运行中必须考虑不超稳定极限功率的条件,而静态和暂态稳定极限功率一般又比导线的热稳定功率(电流)小,另外,由于为满足暂态稳定的要求,线路正常运行时传输的有功功率有时不宜大于(0.0.75)P

没图怎么看呀

线路传输的稳定极限功率.由于电网联络线运行中必须考虑不超稳定极限功率的条件,而静态和暂态稳定极限功率一般又比导线的热稳定功率(电流)小,另外,由于为满足暂态稳定的要求,线路正常运行时传输的有功功率有时不宜大于(0.0.75)P

先将网路按供电点断开,先用力矩法初步计算段功率分布,找出有功无功分点,按分点再将网络断开成两个干式再按干式计算就可以了

1．（1）争先恐后（2）地动山摇（3）源源不断
2．B
3．B
4．最后两句都是。

用电设备的额定电压与电力网的额定电压相等；发电机的额定电压等于连接电网额定电压的1.05倍；变压器一次绕组额定电压一般与连接电网额定电压相等,但与发电机直接相连者等于发电机额定电压；变压器二次绕组额定电压一般等于连接电网额定电压的1.1倍,三者之间都有一定的倍数关系,华天电力上面很多都是关于这方面的.但空载变压器或经短线路与用户相连或小阻抗变压器其二次绕组额定电压等于连接电网额定电压的1.05倍.

电力网中,当电感元件与电容元件发生串联且阻抗等于容抗时,就会发生（ B ）谐振现象