Jingxiong intercity may use permanent magnet high-speed train The feasibility is being explored

A few days ago, Meng Donghua, deputy chief engineer of CRRC Sifang Company, said at the 2018 China Permanent Magnet Drive Technology Seminar that China's permanent magnet high-speed rail trains have completed 300,000 kilometers of performance tests, and are currently exploring the feasibility
of adopting permanent magnet high-speed rail schemes in Beijing-Xiongxiong intercity.

China is one of the few countries
in the world that has mastered the technology of high-speed rail permanent magnet traction system.
Metro trains with permanent magnet traction technology are already running on several urban subway lines, but high-speed trains based on permanent magnet traction technology are not yet commercially available
.
As the first major project in Xiong'an New Area, Beijing-Xiong'an Intercity started construction in February this year, the Beijing section will open in September next year, and the new airport to Xiong'an section is expected to be put into use
by the end of 2020.

Feng Jianghua, chief engineer of CRRC Zhuzhou Electric Locomotive Research Institute, introduced that the reason why it is called permanent magnet high-speed rail is because it uses permanent magnet motors, and previous high-speed rail trains used asynchronous motors
.

Simply put, the motor is driven by electromagnetic force, so it needs to have a magnetic field
.
Asynchronous motor is to establish a magnetic field by absorbing reactive current, but the speed of the rotor is lower than the speed of the rotating magnetic field, so it is called asynchronous motor
.

Feng Jianghua said that the speed of the rotor of the permanent magnet motor and the frequency of the stator are always synchronized
.
The current used to establish the magnetic field will also be lost, so permanent magnet motors are more energy-efficient
than asynchronous motors.

So, why weren't permanent magnet motors used a lot before?

Because no suitable permanent magnet could be found
.
Everyone comes into contact with magnets in daily life, but the magnetism (magnetic energy product) of magnets is far from enough for high-power motors, until rare earth permanent magnets
are discovered.

Dong Shengzhi, chief expert of the General Institute of Iron and Steel Research, introduced that the rare earth permanent magnet material NdFeB that is now widely used appeared in the 80s, and the price is relatively low, but the magnetism is high
.
"China's rare earth permanent magnet materials have been industrialized, and there was a relatively large distance from Japan and Europe in the past, and now they are not lagging behind them in any aspect
.
" Dong Shengzhi said
.

According to Meng Donghua, in February 2015, the railway company issued the "Technical Conditions for Traction EMUs Based on Permanent Magnet Motor at a Speed of 350 Kilometers per Hour"
.
The permanent magnet high-speed rail project adopts the mode of combining production, education and research, and CRRC Sifang Company undertakes it as a project, including Zhejiang University and Times Electric, a subsidiary of CRRC Zhuzhou
.

From 2014 to 2015, the permanent magnet high-speed railway passed the design review and rolled off the production line of China's first permanent magnet high-speed rail prototype in Qingdao Sifang
.

Since then, after the test has been qualified and accepted, since December 2016, the permanent magnet high-speed rail prototype has begun a long test, and as of June this year, the permanent magnet high-speed rail prototype has completed the 300,000-kilometer application assessment and completed the decomposition inspection
.

Feng Jianghua, chief engineer of CRRC Zhuzhou Electric Locomotive Research Institute, said that the test achieved the same running speed of 350 kilometers per hour as Fuxing, and the test showed that the permanent magnet high-speed rail was more efficient than the Fuxing EMU, and the permanent magnet high-speed rail operation was 10%
less energy consumption than the existing high-speed EMU.

Meng Donghua specifically introduced that when the permanent magnet traction high-speed EMU was tested on the Great Western Line, it was still more energy-efficient than the CRH380A (380 km/h high-speed EMU) in the Shanghai-Hangzhou
Line test under the condition of poor curves, tunnels and other line conditions.
In June 2017, the permanent magnet traction high-speed EMU and CRH380A EMU carried out a comparative test of energy consumption on the Chengdu-Chongqing Line, in which the energy saving of the whole vehicle was about 8.
4% in the working conditions of long-distance and large station stops, and the energy saving of the whole vehicle in the working conditions with more stops was about 10%.

Meng Donghua introduced that the design of the permanent magnet high-speed rail is similar to the CRH380A, and the section, main structure and front end are similar to the Harmony, "mainly considering that passengers have accepted
the appearance of the existing high-speed rail.
" ”

However, there are still changes in permanent magnet high-speed trains, such as the wheelbase increased from 2500mm to 2600mm
.
The bigger change is that with permanent magnet motors, there are fewer carriages that need to be equipped with a power system
.

"A group of 8-car EMUs, originally required 6 cars to be equipped with power, after the use of permanent magnet synchronous traction system, only 4 carriages need to be equipped with power, which reduces the dynamic towing ratio (that is, refers to the ratio of power cars to non-powered cars in a fixed train group), that is, it used to be 6 movings and 2 tows, and the permanent magnet high-speed rail only needs 4 movings and 4 tows, saving the traction system cost
of 2 EMUs.
" Meng Donghua said
.

In Meng Donghua's view, the permanent magnet traction system has obvious advantages in power density and energy saving, and is also being promoted and applied
in the field of rail transit abroad.
China has the world's largest railway network, so energy saving and consumption reduction of high-speed trains are particularly important
.
Permanent magnet high-speed iron has the advantages of loss bottom and high efficiency, and will be industrialized and promoted
in the future.