High-voltage direct current circuit breakers(HVDC CB)are one of the key technologies of multi-terminal DC systems and DC grids.Different from other equipment that use a large number of power electronic devices,the HVD...High-voltage direct current circuit breakers(HVDC CB)are one of the key technologies of multi-terminal DC systems and DC grids.Different from other equipment that use a large number of power electronic devices,the HVDC CB cannot obtain its power from the primary system at high potential,making the power supply of the complex multiple electrical potential equipment in HVDC CB a challenge.In this study,the authors propose an HV isolated power supply system based on the multi-output high-frequency isolated power supply unit and the cascaded isolation transformer network.This power supply system can support the 500 kV CB to turn-off 25 kA current with 800 kV overvoltage.展开更多
The effect of heat treatment on hardness and impact toughness of CuCr containing rare earth alloy was studied by means of metallographic, XRD, SEM/EDX, TEM and mechanical property test. The results show that the heat ...The effect of heat treatment on hardness and impact toughness of CuCr containing rare earth alloy was studied by means of metallographic, XRD, SEM/EDX, TEM and mechanical property test. The results show that the heat treatment can change the hardness of CuCr alloy, and has smaller influence to its impact toughness. The optimum properties of CuCr containing RE alloy could be obtained by aging treatment at 500 ℃ for 2 h. And the causes of the above changes and the function of RE were analyzed.展开更多
基金This paper was supported by the National Natural Science Foundation of China 51922062the National Key Research and Development Program 2018YFB0904600the Science and Technology projects of State Grid Corporation of China 0711-190TL13433098-10.
文摘High-voltage direct current circuit breakers(HVDC CB)are one of the key technologies of multi-terminal DC systems and DC grids.Different from other equipment that use a large number of power electronic devices,the HVDC CB cannot obtain its power from the primary system at high potential,making the power supply of the complex multiple electrical potential equipment in HVDC CB a challenge.In this study,the authors propose an HV isolated power supply system based on the multi-output high-frequency isolated power supply unit and the cascaded isolation transformer network.This power supply system can support the 500 kV CB to turn-off 25 kA current with 800 kV overvoltage.
文摘The effect of heat treatment on hardness and impact toughness of CuCr containing rare earth alloy was studied by means of metallographic, XRD, SEM/EDX, TEM and mechanical property test. The results show that the heat treatment can change the hardness of CuCr alloy, and has smaller influence to its impact toughness. The optimum properties of CuCr containing RE alloy could be obtained by aging treatment at 500 ℃ for 2 h. And the causes of the above changes and the function of RE were analyzed.
