Question

哪位大侠能帮我把这些翻译成英文，毕业论文要用，急啊~~多谢各位了,不要是机器翻译的啊

2.1变压器变比的影响
由于原算例中的绝大多数变比均为1.0，为比较变比的影响，分别将所有的变比设为0.95、1 .0、1.05，假设变比均在高压侧，其它初值条件与经典计算方法的设置相同，计算结果如表 1所示。
由表1可见，当变比增大时，500 kV电网的短路电流减小，机端的短路电流增加，230 kV系统则有升有降。这看似无什么规律，其实，它们的结论是一致的。只要从本母线看出 去的变压 器变比增加了，变压器支路的等值阻抗将增加，短路电流将减小；反之，变压器支路的等值 阻抗将减小，短路电流将增加。而230 kV系统则在500 kV降压变和本地系统电厂升压变的作用下，短路电流变化可能有升有降。
从表1中还可以看到，变比的大幅变化对短路电流的影响相对较小，其中，NUCPANT站的短路 电流变化幅度最大，其它的厂站变化相对较小。这是由于NUCPANT站的等值阻抗受连接在此 站的两台升压变的影响较大之故。
2.2充电电容和并联补偿的影响
除基于潮流的短路电流计算外，短路电流计算一般均不考虑线路充电电容、线路高抗、低压 并联电容器、电抗器等设备的影响。表2给出了考虑充电电容和并联补偿与否的四种组合方 式下，其短路电流计算结果的变化情况。其中，C表示线路充电电容，S表示节点并 联补偿，未列出的初值条件与经典方法的设置相同。
由表2可见，考虑并联补偿时，短路电流的变化相对较小，而且，考虑并联补偿后，短路电 流的变化有升有降，其中，若是容性补偿占主导影响，短路电流增加，反之，则下降；考虑充电电容时，短路电流的变化幅度较大；若同时考虑充电电容和并联补偿，其影响是两者的叠加.
2.3节点电压值的影响
节点电压的变化时，基于等值电压源法的短路电流计算结果与电压值保持线性关系，所以，表3仅列出了部分节点的计算结果比较。
2.4发电机的出力和功率因素的影响
在短路电流计算中，除基于潮流的短路电流计算外，发电机一般设为空载，所以，发电机的 空载电势与其端电压相同。若发电机处于负载状态，其空载电势将大于发电机端电压，且在 有功功率相同的情况下，功率因素越低，负载率越高，电流越大，空载电势越大，故障前短 路点的母线电压也越高，所以，短路电流越大。表4给出了发电机功率因素变化对短路电流 计算结果的影响，表4的结论与理论分析相吻合。
2.5不同计算方法的比较
为比较采用不同计算方法对短路电流计算结果的影响，选取了以下三种有代表性的计算初值 设置条件。
(1）基于潮流的短路电流计算；
(2）经典短路电流计算方法；
(3）IEC推荐的方法（变比不变，节点电压取1.05pu）。
表5给出了三种方法下短路电流的计算结果。表中，偏差列为该方法计算值与基于潮流的计 算方法的偏差值.
由表5可见，经典方法的计算结果比基于潮流的小，而IEC方法的结果较接近于基于潮流的计 算结果，但依然有个别节点存在较大的偏差，有的偏小，有的偏大，并不能真正反映电网的 短路电流水平。

Answer 1

2.1 Variable ratio transformer
As the example of the vast majority of changes are more than 1.0, than to compare the effects of change were all set to change than 0.95,1 .0,1.05, assuming that changes in the high side than the other initial conditions with the classical method of calculating the settings the same results as shown in table 1.
Can be seen from Table 1, when the ratio increases, 500 kV power grid to reduce the short-circuit current, machine-side to increase the short-circuit current, 230 kV system is mixed. This is seemingly what the law, in fact, their conclusions are the same. As long as from the bus out to see an increase of ratio transformers, transformers slip will increase the equivalent impedance, short-circuit current will be reduced; the other hand, the equivalent impedance transformer slip will reduce short-circuit current will increase. 230 kV and 500 kV system in the step-down change and boost the local system changes the role of the plant, the short-circuit current changes may be mixed.
From table 1 can also see a significant change than the change on the impact of short-circuit current is relatively small, which, NUCPANT station the biggest changes in short-circuit current, and other changes in the plant stand is relatively small. This is due to the equivalent impedance NUCPANT station by connecting two points in this step-up transformation of the larger part of the company.
2.2 charging capacitance and the impact of shunt compensation
In addition to the trend based on the short-circuit current calculation, the short-circuit current calculation in general do not consider the line charging capacitance, high resistance lines, parallel low-voltage capacitors, reactors and other facilities affected. Table 2 gives the charging capacitance and parallel to consider whether or not compensation under the four combinations, the results of its short-circuit current changes in the calculation. Which, C, said capacitor charging circuit, S said node parallel compensation, not listed in the classic method of initial conditions and the same settings.
Can be seen from Table 2, consider the parallel compensation, changes in short-circuit current is relatively small and, given the parallel compensation, changes in short-circuit current rise and fall, which, if the dominant effects of capacitive compensation, short-circuit current to increase, on the contrary, decreased; consider charging capacitance, the short-circuit current changes in the larger; if taking into account the charge compensation capacitor and in parallel, the effects of the superposition of the two.
2.3 The value of the node voltage
Node voltage changes, voltage source based on the law of equivalent short-circuit current and voltage value calculated to maintain a linear relationship, therefore, are listed in Table 3 is only part of the calculation results of the node.
2.4 The output of generators and power factors
In the short-circuit current calculation, with the exception of the trend based on the calculation of the short-circuit current, the generator is set to empty normally, so the no-load generator potential and its the same terminal voltage. If the generator is loaded state, its power will more than no-load terminal voltage generators, and in the case of the same active power, lower power factor, load rate, the greater the current, the greater the potential no-load, failure short-circuit point higher bus voltage, so the greater the short-circuit current. Table 4 gives the change in power factor of generator short-circuit current calculation results of the impact of the conclusions of Table 4 coincide with the theoretical analysis.
2.5 Comparison of different calculation methods
In order to compare different method of calculating short-circuit current calculations of the impact of three selected representative set of initial conditions for the calculation.
(1) Based on the trend of short-circuit current calculation;
(2) the classic method of calculating short-circuit current;
(3) IEC recommended methods (ratio unchanged, the node voltage check 1.05pu).
Table 5 gives the short-circuit current under the three methods of calculation. Table, as the deviation of calculated values with the trend based on the calculation of the deviation.
Can be seen from Table 5, the classical method of calculation than the trend based on a small, but the results closer to those of IEC method of calculation based on the results of the trend, but there are still some large deviations from the node, and some small, some large and the grid does not reflect the actual level of short-circuit current.