Yang Weiping obviously underestimated Lin Yun's emphasis on the new concept of "super nuclear magnetic power motor" as a high-tech product.

An hour and a half later, Lin Yun went and returned. However, this time he did not come alone, but with three strangers in their forties and fifties, dressed in dark blue overalls, who looked like technicians and engineers.

When Yang Weiping saw that the work clothes of the three old men, who might be senior engineers of Liancheng Electric Machinery Factory, all had different oil and rust stains, the trace of dissatisfaction in his heart with Lin Yun coming to disturb him suddenly disappeared.

Yang Weiping was sure that these three old engineers must have just been temporarily invited by Lin Yun from the front line of work. For those technicians who are keen to take root in the forefront of production and research, Yang Weiping has always been very respectful.

After the three old engineers followed Lin Yun into the door, before Lin Yun could introduce them, they heard one of the old engineers with gray hair and a pair of black-framed myopia glasses shouting with obvious excitement: "Director Yang! You are Director Yang!"

"Chi Gong, don't shout, Director Yang is now the head of state of the Eastern Union, we have to change our name to Yang Yuan!" The head on the left was a little bowed, and the tall and thin engineer gently tugged at the corner of his companion's clothes, and reminded softly with a very stern expression.

"Hehe, since everyone recognizes who Director Yang is, I won't waste more words to introduce you again. Lin Yunle smiled and said: "Director, this is Chi Gong, Chi Yaoguang, the current chief engineer of Liancheng Electric Machinery Factory. The one on the left of the pool worker is Liang Zhenbo Liang Gong, and this is Song Chengdong Song Gong, both of whom are deputy chief engineers of Liancheng Electric Machinery Factory, mainly responsible for the technological innovation and research and development of large electric wheel dump trucks. ”

"Chi Gong, Liang Gong, Song Gong, hello, I am very happy to meet three well-known electrical experts in China!" Yang Weiping warmly stepped forward to shake hands with Chi Yaoguang, Liang Zhenbo and Song Chengdong one by one.

"Director Yang. I still remember your speech at the system-wide work forum of the Commission of Science, Technology and Industry for National Defense. Chi Yaoguang said very excitedly: "The Huaxia dream is now a common dream in the hearts of all the technical staff of our Liancheng Electric Machinery Factory! It is also the biggest driving force that supports us to continue to overcome technical difficulties!"

"This is very good!" Yang Weiping gave the other party an appreciative affirmation, nodded and smiled: "The Chinese dream should become the common dream in the hearts of all Chinese people in the world! Only in this way can the great cause of rejuvenation of the Chinese nation be realized more quickly! Come, Chi Gong, Liang Gong, and Song Gong." You may be seated. Hongmei, a guest, help make three cups, no, four cups of tea, hehe, I almost forgot about Lao Lin. ”

"Lord Yang...... Yang Yuan, Minister Lin said that you have a very, very important confidential project to cooperate with our factory, I don't know what it is?" Apparently a little impatiently asked.

"Motor-wise. Yang Weiping replied with a smile: "Based on the principle of nuclear magnetic power generation, a new type of epoch-making motor has been developed, and I have given it a good name, super nuclear magnetic power motor." ”

"NMR Gathering Energy?" Ji Yaoguang muttered with a deep frown: "NMRR...... Nuclear magnetic resonance...... Gathering energy ......"

"Hehe, Chi Gong, don't think about it, I'm using the guise of MRI, but it's actually used to fool foreigners in the future. "Yang Weiping didn't sell Guan Zi again. said with a smile: "Actually, to put it bluntly, it is a variant of the permanent magnet synchronous motor. Although this technology is still far from real NMR shaped energy. However, this does not prevent it from establishing its position as an upstart in the field of electric motors as an epoch-making innovation. ”

"The permanent magnet synchronous motor has high efficiency and good speed regulation efficiency, and our factory has been tackling key technical problems such as no-load iron consumption, load spurious loss, thermal management and motor design and calculation of high-efficiency and high-power density permanent magnet synchronous motor for many years. Chi Yaoguang is obviously the kind of senior "technical control" who completely enters the state when it comes to technology, and he immediately took Yang Weiping's words and said seriously:

"My colleagues and I have conducted a detailed analysis of the too strong field characteristics of automotive permanent magnet synchronous motors powered by sine wave voltage and frequency converter. Moreover, on this basis, the finite element method is used to analyze and calculate the no-load iron consumption of the permanent magnet synchronous motor under the power supply of sine wave voltage and the power supply of the inverter, and the correction coefficient of the iron consumption calculated by the finite element method is obtained. and the relationship between the increase rate of no-load iron consumption and the modulation ratio of the power supply voltage after the inverter is supplied with power. ”

Talking to experts about technical topics is worry-free. Yang Weiping looked at the chief engineer of Liancheng Motor Factory in front of him with great appreciation, nodded along with his words and said: "Then have you ever thought of using an air gap magnetic density harmonic amplitude that comprehensively considers the air-gap magnetic-dense harmonic amplitude and the motor's pole-groove coordination to minimize the air-gap magnetic-dense optimization criterion ironloss_index?"

“ironloss_index…… Core loss index?" Chi Yaoguang suddenly slapped his big thigh, turned his head to Liang Zhenbo and Song Chengdong, and said excitedly: "Old Liang, old Song." Why don't you think we can calculate the core loss index as an optimization criterion?!"

Liang Zhenbo nodded again and again with bright eyes and said: "We can use this optimization criterion to conduct a detailed analysis of the polar arc factor and the outer circle of the rotor of different polar groove combinations, and give the optimal polar arc factor under different polar groove combinations and the optimal auxiliary groove position of the rotor outer circle of the 8-pole 48-groove structure!"

Song Chengdong is also very professional and then Liang Zhenbo said: "We can also solve the problem of complex load spurious loss distribution and difficult to calculate accurately, from the three aspects of stator, rotor and permanent magnet, the load spurious loss of the permanent magnet synchronous motor for vehicles is theoretically analyzed and solved by finite element, and the correction system of the calculation results is obtained by repeated realization." Starting from the stator magnetodynamic potential, the analytical expression formulas of stator load spurious loss and rotor eddy current loss are obtained!"

Sure enough, they are all experts in electrical engineering! Do you have to find a way to dig these three people back to the Eastern Union? While pondering this "despicable" idea in his mind, Yang Weiping stared back and forth at Chi Yaoguang, Liang Zhenbo, and Song Zhendong with admiration, and his expression was almost the same as the big bad wolf who saw Little Red Riding Hood.

In fact, we can also focus on the analysis of the influence of time harmonics and space harmonics of the word magnetodynamic potential on the rotor loss, and directly derive the analytical calculation expression of the eddy current loss of the permanent magnet according to the Max equation, so as to provide a basis for the suppression of the eddy current loss of the permanent magnet. Yang Weiping smiled and continued to guide the thinking of the three motor experts in front of him:

"Through the real yàn test of load spurious loss, the correction coefficient of finite element calculation and the proportional relationship between load spurious loss and motor input power, as well as the variation relationship of stray loss load generated by time harmonic current, are given. Then, the eddy current loss analysis of the permanent magnet is analyzed in detail by using the analytical expression of the eddy current loss of the permanent magnet derived from the Max equation combined with the finite element method, so as to obtain the generally applicable segmentation law. ”

Chi Yaoguang was really inspired and happily said: "If we can get this segmentation law, we can design a permanent magnet eddy current loss test device to verify the correctness of the conclusions obtained by testing the results of permanent magnets of different sizes! Then, according to the installation and size characteristics of the vehicle motor, the most suitable vehicle permanent magnet synchronous motor with circumferential spiral structure is determined!"

Song Chengdong muttered as if fascinated at this time: "If we can design a software specifically for fluid field analysis, then we can easily obtain the relationship between the heat dissipation coefficient of the waterway and the water flow velocity." Moreover, the fluid field can be used to make a detailed analysis of the air flow characteristics in the machine, and the air flow velocity distribution law can be obtained.

On this basis, the 20KW prototype is analyzed and calculated by stabilizing the temperature field and the transient temperature field, and a transient temperature field calculation flow chart and loss correction formula for real-time correction of motor loss can be given, so as to obtain the variation relationship between the allowable short-term overload time and the thermal load, as well as the influence of the control method of the permanent magnet synchronous motor on the electromagnetic design calculation method and parameter coordination of the permanent magnet synchronous motor on the range of the high-efficiency area, the weak magnetic performance, the rotor structure, the pole groove fit and the no-load back electromotive force selection... …”

"OUCC North General Motor Group successfully developed this dedicated software for fluid field analysis a year ago. Yang Weiping induced Chunchun like the wolf grandmother who induced Little Red Riding Hood: "If Song Gong is interested in this aspect, you can go to Donglian with Chi Gong and Liang Gong, and everyone can communicate with each other......

"I said, director, you can't be so unkind!" Lin Yun saw that the situation was different, and quickly opened the topic away, "You said before that you would let Donglian North General Motor Co., Ltd. cooperate with Liancheng Motor Factory to develop super nuclear magnetic power motors, you can't beat the idea of our senior technical talents of Liancheng Motor Factory!"

"Hahaha! Lao Lin, you think too much. Yang Weiping laughed loudly: "Technical exchanges, why are they called exchanges, that is, to often move around each other, communicate with each other, learn from each other, and make progress together." You see, didn't I communicate with Chi Gong, Liang Gong and Song Gong a little bit, so that their thinking diverged infinitely, and suddenly found the correct way to determine the rotor structure, rated power, peak power, power density and high-efficiency zone ratio of the permanent magnet synchronous motor!"

"I often hear people say, 'Listen to your words, it's better to read a book for ten years', I didn't know what this meant before, but today I understand, the ancients didn't deceive me!" Chi Yaoguang got up with deep emotion and bowed deeply to Yang Weiping, "Thank you Director Yang for your guidance, I really benefited a lot today!"

"Thank you, Director Yang!" Liang Zhenbo and Song Chengdong also stood up and bowed to Yang Weiping.

"You're welcome, you're welcome, you're all your own people, you don't need to be so polite. Yang Weiping waved his hand again and again and said with a smile: "As long as we solve the biggest problem of rotor structure finalization together, the development of super nuclear magnetic power motor will definitely achieve breakthrough results!" (To be continued......