The plasma current ramp-up is an important process for tokamak discharge,which directly affects the quality of the plasma and the system resources such as volt-second consumption and plasma current profile.The China F...The plasma current ramp-up is an important process for tokamak discharge,which directly affects the quality of the plasma and the system resources such as volt-second consumption and plasma current profile.The China Fusion Engineering Test Reactor(CFETR)ramp-up discharge is predicted with the tokamak simulation code(TSC).The main plasma parameters,the plasma configuration evolution and coil current evolution are given out.At the same time,the volt-second consumption during CFETR ramp-up is analyzed for different plasma shaping times and different plasma current ramp rates dIP/dt with/without assisted heating.The results show that the earlier shaping time and the faster plasma current ramp rate with auxiliary heating will enable the volt-second to save 5%-10%.At the same time,the system ability to provide the volt-second is probably 470 V·s.These simulations will give some reference to engineering design for CFETR to some degree.展开更多
Prediction of volt-second consumption has been done by the tokamak simulation code （TSC）, which includes the whole plasma discharge of HL-2M conception design. It covers the volt-second consumptions at the entire cu...Prediction of volt-second consumption has been done by the tokamak simulation code （TSC）, which includes the whole plasma discharge of HL-2M conception design. It covers the volt-second consumptions at the entire current ramp-up phase and the plasma flattop phase. More important, the sensitivities of volt-second consumption with respect to the current ramp-up time and the impurity concentration have been studied, respectively.展开更多
直流输电系统的内过电压主要通过金属氧化物避雷器（metal oxide arrester,MOA）加以限制,避雷器在内过电压下的保护特性对确定设备的操作冲击绝缘水平具有重要意义。根据±1 100 k V主回路接线、避雷器配置、交直流系统参数等,建立...直流输电系统的内过电压主要通过金属氧化物避雷器（metal oxide arrester,MOA）加以限制,避雷器在内过电压下的保护特性对确定设备的操作冲击绝缘水平具有重要意义。根据±1 100 k V主回路接线、避雷器配置、交直流系统参数等,建立了±1 100 k V系统内过电压计算模型。对避雷器电压和电流波形进行仿真,对避雷器电流的波头时间进行统计。统计结果为：内过电压下通过避雷器电流的波头时间均不小于100μs,大于标准操作冲击电流的波头时间30μs,需要对较缓电流波头下避雷器的保护特性进行研究。为加以对比,对波形为316/814μs、30/60μs、8/20μs和1/4μs电流下的避雷器伏秒特性和伏安特性进行了试验研究。结果表明,同样电流下,1/4μs的伏安特性曲线高于8/20μs、30/60μs和316/814μs的曲线,而后三者的伏安特性曲线则区别不大;8/20μs、30/60μs和316/814μs的伏安特性相比,在0.1～1 k A电流范围内,30/60μs的伏安特性曲线比8/20μs和316/814μs的伏安特性曲线稍高。由于避雷器操作冲击电流的波头时间均不小于100μs,内过电压下避雷器取30/60μs电流波形下的伏安曲线是合适的,且是稍微偏严的。最后试验测试了避雷器电阻片在30/60μs操作冲击电流下的伏安特性。展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFE0300500 and 2017YFE0300501)the National Natural Science Foundation of China(Grant Nos.11875290 and 11875253)the Fundamental Research Funds for the Central Universities of China(Grant No.WK3420000004).
文摘The plasma current ramp-up is an important process for tokamak discharge,which directly affects the quality of the plasma and the system resources such as volt-second consumption and plasma current profile.The China Fusion Engineering Test Reactor(CFETR)ramp-up discharge is predicted with the tokamak simulation code(TSC).The main plasma parameters,the plasma configuration evolution and coil current evolution are given out.At the same time,the volt-second consumption during CFETR ramp-up is analyzed for different plasma shaping times and different plasma current ramp rates dIP/dt with/without assisted heating.The results show that the earlier shaping time and the faster plasma current ramp rate with auxiliary heating will enable the volt-second to save 5%-10%.At the same time,the system ability to provide the volt-second is probably 470 V·s.These simulations will give some reference to engineering design for CFETR to some degree.
基金supported by the Chinese ITER Assistant Project Foundation (No. 2009GB104008)
文摘Prediction of volt-second consumption has been done by the tokamak simulation code （TSC）, which includes the whole plasma discharge of HL-2M conception design. It covers the volt-second consumptions at the entire current ramp-up phase and the plasma flattop phase. More important, the sensitivities of volt-second consumption with respect to the current ramp-up time and the impurity concentration have been studied, respectively.
文摘直流输电系统的内过电压主要通过金属氧化物避雷器（metal oxide arrester,MOA）加以限制,避雷器在内过电压下的保护特性对确定设备的操作冲击绝缘水平具有重要意义。根据±1 100 k V主回路接线、避雷器配置、交直流系统参数等,建立了±1 100 k V系统内过电压计算模型。对避雷器电压和电流波形进行仿真,对避雷器电流的波头时间进行统计。统计结果为：内过电压下通过避雷器电流的波头时间均不小于100μs,大于标准操作冲击电流的波头时间30μs,需要对较缓电流波头下避雷器的保护特性进行研究。为加以对比,对波形为316/814μs、30/60μs、8/20μs和1/4μs电流下的避雷器伏秒特性和伏安特性进行了试验研究。结果表明,同样电流下,1/4μs的伏安特性曲线高于8/20μs、30/60μs和316/814μs的曲线,而后三者的伏安特性曲线则区别不大;8/20μs、30/60μs和316/814μs的伏安特性相比,在0.1～1 k A电流范围内,30/60μs的伏安特性曲线比8/20μs和316/814μs的伏安特性曲线稍高。由于避雷器操作冲击电流的波头时间均不小于100μs,内过电压下避雷器取30/60μs电流波形下的伏安曲线是合适的,且是稍微偏严的。最后试验测试了避雷器电阻片在30/60μs操作冲击电流下的伏安特性。
