Question

哪位大侠帮忙把这篇文章翻译成英文,不要机器翻译啊,毕业论文用,急啊

配电网络是电力系统中连接输电网络和用户侧的中间环节，直接为广大用户提供电能。与输电网络相比，配电网络具有电压等级低、损耗大、自动化程度低等特点。配电网络的运行工况是否安全、合理，不仅关系到用户侧电能可靠性的优劣，而且还直接影响网络运行的安全性和经济性。对配电网络整定计算进行研究，具有非常重要的实际意义。
配电网络的整定计算主要是短路电流计算。随着配电网络规模不断扩大，电力系统继电保护装置的数量不断增加，质量不断提高，继电保护管理工作的复杂程度和技术难度也不断增加。这给传统的继电保护管理方法和工作方法带来了挑战。因此，开发一套面向工程实际的完整的继电保护整定程序，对提高保护计算的工作效率和有效性，具有极其重要的现实意义和理论意义，而继电保护整定计算程序的核心就是配电网络的继电保护整定计算。
本文以各种短路故障经典算例和通过分析一个典型系统为例来介绍配电网络故障电流的计算和系统的应用情况，并对系统的进一步完善和发展进行了探讨。在电力系统投入运行前和实际运行参数改变时，都需要通过短路计算，求解流经某些电气设备的短路电流，对继电保护整定值及设备的关键参数进行校验，以确保电力设备安全运行。
正确掌握电力系统短路电流计算的基本原理和方法，是能否正确设置电气设备继电保护整定值和相关参数的关键。因此，短路电流计算模块是各种保护整定计算软件中最核心、最关键的部分。在进行短路电流计算时，一般首先都要通过网络化简，求解各个电源对短路点的转移阻抗，然后利用线性电路的叠加性，求解短路点的起始次暂态电流、冲击电流以及所需的开断容量等。从而通过计算得知设备所经受的冲击电流和需要的开断容量，给选择设备提供技术依据。与此同时，还可以通过计算得知电气设备在各种故障状态下的故障电流，通过互感器变换得知其二次电流，从而给保护设备进行定值整定，确保保护设备能够按照要求在故障发生时切除故障设备，缩小事故范围，确保电力系统安全运行。这些工作在电力系统日常工作中的作用也就显得尤其重要和有意义。
本文主要介绍了短路电流计算的具体步骤和计算方法。通过分析一个常见的11OkV电压等级系统，使用两种不同的方法对其进行计算，这两种方法具体为:一种是直接利用电源支路电流进行计算，另一种是利用系统转移阻抗进行计算。
发现两种求解方法的计算结果存在差异。对差异产生的原因进行深入分析后发现，只有当系统的电源性质完全相同时，两种方法才完全等效;而当系统的电源性质不同且需要求解短路冲击电流时，则建议采用第一种求解方法，否则将会造成较大的误差。本文的研究工作对于寻求合理方法进行电力系统实用短路电流计算具有一定的借鉴意义。

Answer 1

The distribution network is in power system and power transmission network connection among the link directly to the vast number of users with electricity. Compared with the transmission network, with low voltage distribution network, the loss is big, the low degree of automation. The operating condition of the distribution network security, whether reasonable, is not only related to the user, the reliability of the lateral power but also directly affect the safety of network operation, and the economy. The calculation of the distribution network research, has very important practical significance.
The calculation of the distribution network is mainly short-circuit current calculation. With the distribution network scale unceasingly expands, the power system protection device of increasing of quantity and quality enhances unceasingly, relay protection management of complexity and difficulty of technology are also increasing. The traditional method of relay protection management methods and challenges. Therefore, the development of a practical complete relay protection setting procedure, to improve the working efficiency and protect computation efficiency, has important realistic meaning and theoretical significance and relay protection setting calculation procedure of the core is the distribution network of relay protection setting calculation.
Based on the classic example of fault and through the analysis of a typical system as an example to introduce the distribution network fault current calculation and the application of the system, and to further improvement and development of the system are discussed. In power system and the actual operation before the operation parameters change, all need through short circuit calculation, solving some electrical equipment through the short-circuit current, relay protection setting value and the key parameter calibration equipment, electric equipment to ensure safe operation.
Power system correctly grasp the basic principle of short-circuit current calculation method is correct and relay protection setting electrical equipment and related parameters of the value of the key. Therefore, short-circuit current calculation module is various protection setting calculation software in the core and key parts. In general, short-circuit current calculation when first through the network to solve various power, Jane short-circuit point of transfer, then linear circuit impedance of additive, short-circuit point is the starting time of transient current, current and the required open capacity, etc. And through the calculation of the electric equipment and experienced impact to open to choose equipment capacity and provide technical basis. Meanwhile, through calculation of electrical equipment in various fault condition, through the fault current transformer, transform and quadratieally learned to protect equipment to ensure the setting value, in accordance with the requirements in protecting equipment failure, reduce accidents resection fault equipment, to ensure safe operation of the power system. These work in power system in the daily work also appears especially important and meaningful.
This paper introduces the concrete steps to short-circuit current calculation method and calculation. Through the analysis of a common 11OkV voltage rating system, using two different methods of calculation, the two methods for specific: one kind is directly use power branch current calculation, another kind is calculated using the system transfer impedance.
Find two kinds of methods for solving the calculation result differences. The reasons of difference analysis, found only when the power supply system, totally two methods to completely equivalent, When the system's power to solve different properties and short-circuit current, suggest the first kind of solving method, otherwise will cause greater error. This research work for a reasonable method for power system of short-circuit current calculation has certain practical significance.