China's rail transit has added another "star" - high-speed maglev trains. Recently, the 600 kilometer high-speed maglev test vehicle was officially launched in Qingdao, Shandong.

This is a fruitful achievement of the national key research and development program "Advanced Rail Transit", marking a major breakthrough in China's high-speed maglev technology field. With long-term and profound technological accumulation and close integration of industry, academia, research and application, scientists and engineers have made a series of breakthroughs in key technologies of high-speed maglev transportation systems such as suspension guidance, traction control, and operation control communication in the past three years, consolidating China's technological advantages in the field of rail transit and firmly mastering key core technologies in their own hands.

Proactively layout and promote the high-speed maglev industry

The blue and gray, sci-fi shaped front of the car can be called a luxurious interior comparable to an airplane. The ultra high speed maglev test car with a specially treated paint surface shines brightly in the sunlight.

On May 23rd, the key technology stage achievement report meeting of high-speed maglev transportation system and the first high-speed maglev test vehicle offline ceremony were held in Qingdao. This train, which can reach a speed of 600 kilometers per hour, unveiled its mysterious veil to the world for the first time.

The next five years will be a crucial period for the development of the high-speed maglev industry, as well as the initial formation of the global high-speed maglev industry pattern, "said He Huawu, Vice President and Academician of the Chinese Academy of Engineering." High speed maglev transportation has become the trend and direction of global rail transit

As a new cutting-edge rail transit technology, high-speed maglev has attracted increasing attention from countries. Developed countries such as Germany and Japan have developed various maglev transportation solutions using different technological routes.

China began deploying the research and development of high-speed maglev transportation systems in 2016, with the aim of developing a high-speed maglev engineering system with independent intellectual property rights and a speed of 600 kilometers per hour, forming the industrialization capability of high-speed maglev in China.

High speed maglev will change people's perception of transportation and distance, achieving a transportation pattern of commuting for 500 kilometers, intercity for 1000-1500 kilometers, and corridor for 2000-2500 kilometers, "Jia Limin, the overall expert group leader of the National Key Research and Development Program" Advanced Rail Transit ", told Science and Technology Daily reporters.

Breaking through core technology is just a tiny fraction away

To suspend a massive vehicle loaded with passengers on the track and accelerate at a speed of 600 kilometers per hour, multiple core key technologies for rail transit need to be addressed.

One of the key requirements is that the distance between the train and the track must be kept stable within 10 millimeters. This imposes strict requirements on suspension guidance and other systems. To solve this problem, engineers installed multiple sensors on the train to "report" the distance between the body and the track to the control system in real time, and then controlled the distance within the set range by adjusting the current strength.

This requires us to ensure effective motion decoupling between the magnet, suspension frame, and vehicle body, and to use methods such as vehicle rail coupling, suspension optimization, and suspension guidance system coordination to solve a series of problems including self-excited vibration, "Ding Sansan, the head of the high-speed maglev project and deputy chief engineer of CRRC Sifang Co., Ltd., told Science and Technology Daily reporters.

Due to the high-speed movement of the train, the position of the vehicle and the track constantly changes. Therefore, the installed sensors must be very "smart" and provide feedback in a short period of time. We have reduced the response time from 0.824 seconds to 0.01 seconds by optimizing the magnet capability, response bandwidth and control algorithm, and introducing current negative feedback, "said Ding Sansan.

From the perspective of parameters and technical indicators, this test vehicle has reached the international leading level in high-precision suspension guidance, speed measurement and positioning devices, and control systems, achieving phased results.

There are still many challenges brought by ultra high speed, and wind resistance is one of them. At that time, the speed reached 600 kilometers per hour, and aerodynamic resistance accounted for over 90%. In order to solve a series of problems such as aerodynamic resistance, strength, and stiffness under ultra high speed conditions, CRRC Sifang has specially developed a new generation of lightweight and high-strength vehicle bodies. The new generation of car body uses carbon fiber sealing material, which reduces weight by 30% compared to aluminum alloy; Specially developed 3D woven suspension frames and other components have improved their fatigue strength and damping characteristics.

In terms of processing technology, the new car body adopts laser composite welding technology, which improves the accuracy by three times compared to arc welding, with an error of only ± 1 millimeter. When installing internal components, it's almost always a one-time success, which was unimaginable before, "Ding Sansan said." This provides great convenience for later production and maintenance

It is this tiny breakthrough that showcases the true strength of Chinese manufacturing.

Collaborative operation of the 'Joint Fleet' to create a Chinese style technological innovation system

The high-speed maglev transportation system is organized by CRRC Corporation Limited and implemented by CRRC Qingdao Sifang Locomotive and Rolling Stock Co., Ltd. It gathers advantageous resources in the domestic high-speed rail and maglev fields, and has formed a "joint fleet" consisting of more than 30 enterprises, universities, and research institutes to carry out technological research and development. In collaborative operations, participating units have cooperated seamlessly, with close links between production, academia, research, and application, achieving phased results.
This project is led by leading industrial enterprises, allocating advantageous industries and innovative resources, gathering advantageous institutions, and fully utilizing the resources and technologies accumulated in the past, "said Jia Limin. Although the project has only been launched for 3 years, it embodies China's wisdom, experience, and technology in the field of rail transit over the years.

Ding Sansan also stated that in the process of technological breakthroughs, he drew on the rigorous research and development process of high-speed rail science, the long-term accumulation of high-speed maglev and high-speed wheel rail, systematically optimized the scientific research and development process, and established a joint R&D team across industries, specialties, and units, dividing labor and collaborating for collaborative innovation.

Relying on the Chinese style technological innovation system, the research team has overcome a series of core technologies such as traction operation control, suspension guidance, vehicle ground communication, and ultra high strength vehicle body. We can proudly say that China's high-speed maglev has developed from the research and development stage to the engineering and industrialization stage. China's high-speed maglev industry is showing vigorous vitality and will become an indispensable force in the global high-speed maglev industry and market development, "said He Huawu. (Source: China National Radio)