At the beginning of December, 2017, CRH6F-A intercity EMU which was equipped with no-speed sensor electric transmission system independently developed by CRRC Xi’an YongeJieTong Electric Co., Ltd. has been type testified successfully. Test data indicates that all the performances of electric transmission system that applies no-speed sensor control technology could fully meet technology requirements of EMU. The accomplishment of type test implies that the EMU mentioned above achieved certification of operating, and represents that independently developed no-speed sensor control technology has been applied in high speed EMU field successfully in China for the first time.
The accomplishment and application of no-speed sensor control technology in EMU field decrease the number of EMU transmission system test hardware, and avoid all kinds of hardware faults. On the one hand, it makes system volume smaller, weight lighter, and system maintenance more convenient. On the other hand, it decreases motor fault rate greatly, and improves system reliability. The technology has been applied in EMU successfully, which remarks a significant breakthrough in the core technology of electric transmission system that is developed independently in China.
In order to monitor rotate speed in real time, proceed real time control of transmission and breaking characteristic, and make traction motor in normal or optimum working condition, the rail transit transmission electric system traditional practice is installing speed sensor in traction motor. However, due to temperature changes in the installation location, vibration, electromagnetic interference and other working environments, the speed sensor becomes a bottleneck restricting the reliability of the transmission system, and the fault rate accounts for about 70% of the total fault of the traction motor.
CRRC Xi’an YongeJieTong Electric Co., Ltd. Is a primary subsidiary of CRRC Yongji Electric Co., Ltd. It focuses on research and innovation of rail transit electric transmission technology, tackled this technology in urban rail transit electric transmission system in 2015, solved the problems of no-speed sensor control of low speed zone stability, initial speed identification, dynamic response speed and control accuracy, launched AC electric transmission system with no-speed sensor control technology which has been widely used in urban rail transit field. This technology has been used in transmission electric systems which have won the bidding in Beijing, Shanghai and Xi’an with more than 200 operating vehicles.