Flexible DC transmission is an important way to solve the highly efficient development and utilization of renewable energy such as wind power. DC grid technology has become an important direction for the development of international power grid technology. Compared with AC current, DC current is difficult to break due to no "natural zero crossing", especially under high voltage and high current conditions. This problem is even more severe. In addition, the DC short-circuit current rises quickly, requiring it to be opened within a few milliseconds after the short-circuit occurs. Therefore, the rapid opening and breaking of direct current under high voltage and high current conditions and the corresponding high-voltage direct current circuit breakers have become the main bottleneck problem for limiting the development of the direct current power grid. At present, it has become a research hotspot at home and abroad. In order to better master the key technologies of high-voltage direct current circuit breakers, new equipment with complete intellectual property rights in China has been developed to remove obstacles for the development of DC power grids. Leading by China Southern Power Grid Science Research Institute, China Xidian Electric Co., Ltd., Xi'an High-voltage Electrical Equipment Research Institute, Xi'an Jiaotong University and Shenzhen Power Supply Bureau jointly undertook the national 863 project "Key Circuit Breaker Technology Study." After nearly two years of research in the research group, through cooperation with universities and enterprises, the research of high-voltage direct current circuit breakers in China has developed rapidly, especially in the research of high-voltage DC breaking technology based on artificial zero-crossings. : Such as in the DC high-speed operating mechanism, rapid transfer of short-circuit current, energy absorption, multi-fault series, test methods and other important progress has been made, for the first time in China developed a 55kV high-voltage DC circuit breaker unit prototype with independent intellectual property rights, and The National High Voltage Electrical Appliance Quality Supervision and Inspection Center passed the test and successfully switched off the current of 16kA. The breaking time was less than 5ms. According to the test situation, the research team preliminarily determined that the next step will be to use a series of prototypes to achieve higher voltage levels. It is expected that the development and testing of 110 kV and above high-voltage DC circuit breaker prototypes will be completed in 2015. On December 23, 2014, the research group organized a DC circuit breaker technology seminar in Shenzhen. The meeting was presided over by Rao Wang, dean of the South China Research Institute. He invited academicians Li Lizhen, Academician Zheng Jianchao, Academician Qiu Aici, and professors from colleges and universities in the power industry. Experts from the equipment manufacturers came to the guide. The research team reported on the research progress and the phased results of the project. They were highly praised by the participating experts and made suggestions on the next step of the research. Aircraft Axe With Fiberglass Handle Fiberglass Handle Aircraft Axe Hammer,1000G Aircraft Axe Fiberglass,800G Aircraft Axe Fiberglass Handle,Aircraft Axe With Fiberglass Handle CHANGZHOU YIYITOOLS FACTORY , https://www.czyiyitools.com