At this time, two teachers, a man and a woman, entered the classroom with a thick sealed bag, the male teacher was responsible for unpacking, and the female teacher was responsible for explaining the examination room: "Everyone must have understood the examination arrangement, I will reiterate again, the morning test of mathematics and English, the afternoon political and professional, the preliminary examination and re-examination of this exam will be carried out together, and the written test will be completed at 4 o'clock, everyone should not be in a hurry to go, waiting for the interview arrangement." ”

"Is the interview also today?" asked the middle-aged oil man in surprise.

"Professor Yue is going on a business trip tomorrow, and it may be late to arrange it until today, so please forgive me. ”

There was a commotion in the classroom.

After all, except for Zhang Yifu and Xia Xue, the rest of them have hardly contacted Yue Yunhe, and they haven't said yes, so it is undoubtedly a good thing to have the opportunity to meet and chat today, and they must leave a good impression on the professor.

In such confusion, Zhang Yifu began to answer the questionnaire.

I got the math paper and swept around, I have to say that Xia Xue's review is too useful, she is simply the queen of the exam, most of these question types are familiar, Xia Xue's essence question bank is simply cool.

It's definitely no problem to pass, so try to reach the average.

After taking the math test, Zhang Yifu probably answered the right answers with Xia Xue and Touyounan, and he should be able to reach the average, but Touyounan's performance seems to be better than himself, but he still can't compare with Xia Xue.

After that, it was the English of the heavens, and after a confused pass, Zhang Yifu could only pass the prayer.

I didn't have much time for lunch, so I found a casserole shop at school to deal with it.

After noon, he forcibly passed the political examination in the lazy daylight, and the political examination was easier than Zhang Yifu imagined, because these things came and went, and he used "Marx Theory" to argue a qiē, and there was even a lot of dabbling in the question bank in his head, and it must not be difficult to rely on micro-cheating to reach the average.

Ultimately. Finally, we ushered in the professional examination paper, which includes the examination paper of electric motors, power and engineering.

Zhang Yifu and Xia Xue are undergraduates in power systems, and they have a little knowledge of these aspects. But it's not too deep, and this must be Xia Xue's most important review. Zhang Yifu is the most contemptuous. Swept his eyes and scrolled, because it was the direction of the power system, which involved limited mechanical and power aspects, Zhang Yifu was a little relieved, and Xia Xue should be able to deal with it.

This professional test question is actually the content of the retest.

In the preliminary examination, those who pass the line participate in the re-examination, which includes a professional written test and an interview.

The core of this is actually the score line of the initial test.

The general gameplay is like this. The key here is "a certain percentage", because a certain proportion is not a certain percentage, and Chinese is always so broad and profound. Considering the worst case, if Jia Tianyun refers to it, and to ensure that she is admitted, then the score line of the preliminary examination. is almost Jia Tianyun's total score, if she scores 0 in the test, the proportion is 100%. Then all the staff are happy to pass the first try.

In this way, the retest is easy to operate, as soon as Grandma Jia appears, all the tutors surrender and give full marks.

Therefore, for Zhang Yifu, this professional written test paper is more important than the previous test papers, and the score line of the preliminary examination will definitely be stuck with his own score. Otherwise, it will be too embarrassing for Lao Yue.

On this paper, there are no choice or judgment questions. It's all subjective questions, and the test is all hard knowledge. There was no luck factor.

The frontispiece is a series of sentimental questions, and the first one is easy to panic -

[Brief introduction of electrostatic shielding, electromagnetic shielding and magnetostatic shielding]

First of all, this question makes people's scalp numb, after Zhang Yifu tried his best to write the answer, he still felt numb when he looked at the answers he gave, and no one could understand it except for professionals.

[What are the four parameters of the equivalent circuit of the transformer, and how to obtain them through the guò test]

This is simpler, but it is still the first to blow, these are the two easiest questions in the professional test of Jinghua Electrical Engineering...... If you don't memorize all the basic teachings and don't think about answering these terrible detailed feelings, Rao is Zhang Yifu, and he can't rely on conventional memory to complete it, so he has to use the "computer". Exams and work are really two different things, absolutely two different things.

The concept questions were not answered, and before I knew it, three or five people had already handed in the papers, and it was obviously unrealistic to complete these questions in 10 minutes.

This is also normal, after all, they reviewed the unified examination before, and in terms of the regular examination, they have to wait for the unified examination to pass guò and then take the professional course, many people who meet the conditions to take the exam, and they are not necessarily motor majors, just to try their luck, as soon as they get on the motor question, they will blow up directly.

After the female invigilator received such a few papers, she also said helplessly: "Professor Yue has very high requirements for the major, no matter how good the number of British politics is, it is not good to answer the professional well, these questions are the easiest, and the interview behind is a high-pressure question, if this paper cannot be answered 70%, I personally recommend that you can submit the paper in advance." ”

Many people seemed to have been stabbed, showing painful expressions.

The male teacher frowned when he heard this: "It's not so exaggerated, let's fight for it." ”

"Isn't that a time-saver? The female teacher continued, "I know, most of you are after taking the unified examination, come to try your luck, maybe the unified examination is not the electrical major at all, Professor Yue said very clearly, at most two people, if they are not satisfied, he may accept it again next year." ”

The male teacher shook his head and said no more.

In fact, the female teacher's threat was very meaningful, and after she spoke, seven or eight people chose to give up, and less than 20 people finally chose to insist on answering the question.

Only then did the female teacher show a satisfied smile, control the number of interviews, and get off work early.

To say that Zhang Yifu is also a person who has experienced the national competition, but it is more difficult to answer the questions in front of him, the reason is very simple, this paper is more theoretical, more in-depth, and the national competition focuses on practice, many of which are problems that will be encountered in the work, more conventional problems.

I tried my best to do the last question, and time was running out.

Unexpectedly, the last question was not a drawing question, nor a calculation question, but an essay question! This saved Zhang Yifu a lot of effort.

Looking at the title description again, Zhang Yifu couldn't help but be dumbfounded.

How is it possible? How can anyone be able to answer this kind of question?

The reason is simple...... Because I am afraid that even Yue Yunhe himself does not have a standard answer to this question, because this question belongs to the future.

The question is divided into three questions.

[1: Please briefly describe the significance and principle of series capacitance compensation]

[2: Please briefly describe the difficulties of series capacitance compensation in the application]

[3. Suppose a power plant has 8x600MW supercritical units, in order to improve the transmission capacity, three 500kV transmission lines are equipped with capacitance compensation devices, and the series compensation degrees are 35%, 40% and 45% respectively, please try to propose a suppression scheme for the subsynchronous oscillation of the 600mV units of the power plant. 】

Just like these three questions, the unreality of this question is sublimated with each question.

The first question is series capacitance compensation, first of all, this is a niche and unpopular and highly professional, almost blank transmission technology in China, even if it is a scholar Xia Xue, he may not be able to know this concept.

The second question is the difficulties in the application, which goes further, and there is no application in China, how to talk about the difficulties?

Q3...... Looking at the parameters and the configuration, isn't it the Beidesert Thermal Power Plant? A power plant that has not yet been built! How can a textbook mention a power plant of this scale that belongs to the future?

Let's talk about how to solve the impact of series capacitance compensation in the process of power transmission, which is a big problem that Yue Yunhe should study, a matter that national transmission experts should study, and a big problem to be solved in the next three years.

How is it possible for humans to answer?

Of course, there are also people who can answer, such as the chief engineer of the American power company, the doctoral supervisor of the Massachusetts Institute of Technology, etc., but they are already non-humans, and they are thousands of miles away, how can they be idle to take this exam.

There is only one answer.

This question was tested by Yue Yunhe for Zhang Yifu, and he was only tested to see if he could talk about the most difficult point in his future work.

Zhang Yifu was also very embarrassed, let Lao Tzu talk, Lao Tzu will definitely be able to talk, and he doesn't care about showing his superhuman talent, the question is...... This matter is enough to write a paper, and 50,000 words may not be able to talk about it thoroughly.

Series capacitance compensation this matter, can be referred to as series compensation, in the ministry to see Pang Bayi when they Zhang Yifu has proposed, this is a technical means to improve the efficiency of AC transmission, but this is also a double-edged sword, series compensation caused by the sub-synchronous oscillation problem if not effectively dealt with, will have a devastating blow to the large shaft of the turbine generator, the Yankees have lost several supercritical units because of this matter.

In our country, we have always pursued stability, so even if this technology has appeared for more than 20 years, because of the risk, in order to be stable, we have not dared to use, low transmission efficiency is low, after all, the large shaft is the most important core part of the generator set, and no one can afford to be responsible for the damage.

But in the end, technology is to progress, efficiency is to be improved, China's situation itself is the uneven distribution of natural resources, power plant configuration must also be uneven, the requirements for long-distance transmission are great, especially in the North Desert this power generation is so huge, a considerable part of the power plant directly supplied to Jijing, do not consider the efficiency is really not enough, and the international series supplement technology has become mature, as a power country we should not fall behind.

Therefore, in the demonstration report of Beimo, it was proposed for the first time to use tandem compensation technology in power transmission projects, and Yue Yunhe was obviously a person who could afford to carry the pot.

The principle of series compensation is very complex, the device is very large, but the effect is very intuitive, if you play a slip, the loss of a 300 km transmission line can be reduced to about 180 km or even lower, this huge benefit, but also the reason why people dare to take risks, once you can control the subsequent sub-synchronous oscillation, it will also control the risk. (To be continued) R655