In large tokamaks, disruption of high current plasma would damage plasma facing component surfaces （PFCs） or other inner components due to high heat load, electromagnetic force load and runaway electrons. It would a...In large tokamaks, disruption of high current plasma would damage plasma facing component surfaces （PFCs） or other inner components due to high heat load, electromagnetic force load and runaway electrons. It would also influence the subsequent plasma discharge due to production of impurities during disruptions. So the avoidance and mitigation of disruptions is essential for the next generation of tokamaks, such as ITER. Massive gas injection （MGI） is a promising method of disruption mitigation. A new fast valve has been developed successfully on EAST. The valve can be opened in 0.5 ms, and the duration of open state is largely dependent on the gas pressure and capacitor voltage. The throughput of the valve can be adjusted from 0 mbar·L to 700 mbar·L by changing the capacitor voltage and gas pressure. The response time and throughput of the fast valve can meet the requirement of disruption mitigation on EAST. In the last round campaign of EAST and HT-7 in 2010, the fast valve has operated successfully. He and Ar was used for the disruption mitigation on HT-7. By injecting the proper amount of gas, the current quench rate could be slowed down, and the impurities radiation would be greatly improved. In elongated plasmas of EAST discharges, the experimental data is opposite to that which is expected.展开更多
A gas injector was designed for the 400 J/pulse prototype of the planar inductive pulsed plasma thruster（IPPT） developed by the National University of Defense Technology（NUDT_IPPTx）.As the gas puff distribution ov...A gas injector was designed for the 400 J/pulse prototype of the planar inductive pulsed plasma thruster（IPPT） developed by the National University of Defense Technology（NUDT_IPPTx）.As the gas puff distribution over the coil surface is critical to the NUDT_IPPTx functioning efficiently, a fast ionization gauge was developed to investigate the neutral gas pressure profiles to seek the critical time when the thruster is ignited. The gauge was calibrated for argon by using a capacitance manometer. Time-resolved pressure profiles have been acquired in the condition of the gas puff mass matching with the discharge energy and the drive coil parameters of the NUDT_IPPTx. It is demonstrated that the gas injector can supply a gas puff with a sufficiently steep（dp/dt？≈？770 kPa s-1） leading and trailing edge, and the gas puff can be compressed against the drive coil as expected. The critical ignition moment is considered to appear at some instant between 525 μs and 650 μs after the valve trigger.展开更多
Based on the features and requirements of gas drainage system, an optimized explosion resistance technology is done after a comprehensive analysis and research about the triple IR （Infrared Ray） flame detection tech...Based on the features and requirements of gas drainage system, an optimized explosion resistance technology is done after a comprehensive analysis and research about the triple IR （Infrared Ray） flame detection technology, explosion resistance valve technology and explosion resistance control technology. An intelligent PLC （Programmable Logic Controller） resistance control system is designed which can cut offthe gas branch quickly and accurately, and the controller have automatic pressure maintaining function, valve rotation limit function, remote and local control interlock function. The reliability and rationality of explosion resistance technology is verified by gas pipeline explosion propagation and resistance simulation test. Overall response time of explosion resistance system is less than 100ms, and the spread of fire in gas pipeline can be prevented effectively.展开更多
This paper studies the nonlinear variable structure control (VSC) technique for designing power system integrate control systems which include an excitation controller and fast valve controller.A new method is applied...This paper studies the nonlinear variable structure control (VSC) technique for designing power system integrate control systems which include an excitation controller and fast valve controller.A new method is applied to find nonlinear switching surface in deriving the control strategy.The responses to various large perturbation are simulated.The simuulation results show that the nonlinear VSC technique for integrated control systems can considerably improve the transient stabilization limitation of power systems and improve the dynamic properties of the generators.展开更多
基金supported by National Natural Science Foundation of China(No.085JM66502)
文摘In large tokamaks, disruption of high current plasma would damage plasma facing component surfaces （PFCs） or other inner components due to high heat load, electromagnetic force load and runaway electrons. It would also influence the subsequent plasma discharge due to production of impurities during disruptions. So the avoidance and mitigation of disruptions is essential for the next generation of tokamaks, such as ITER. Massive gas injection （MGI） is a promising method of disruption mitigation. A new fast valve has been developed successfully on EAST. The valve can be opened in 0.5 ms, and the duration of open state is largely dependent on the gas pressure and capacitor voltage. The throughput of the valve can be adjusted from 0 mbar·L to 700 mbar·L by changing the capacitor voltage and gas pressure. The response time and throughput of the fast valve can meet the requirement of disruption mitigation on EAST. In the last round campaign of EAST and HT-7 in 2010, the fast valve has operated successfully. He and Ar was used for the disruption mitigation on HT-7. By injecting the proper amount of gas, the current quench rate could be slowed down, and the impurities radiation would be greatly improved. In elongated plasmas of EAST discharges, the experimental data is opposite to that which is expected.
基金supported by National Natural Science Foundation of China(No.51306203)the Natural Science Foundation of Hunan Province(No.2018JJ3592)
文摘A gas injector was designed for the 400 J/pulse prototype of the planar inductive pulsed plasma thruster（IPPT） developed by the National University of Defense Technology（NUDT_IPPTx）.As the gas puff distribution over the coil surface is critical to the NUDT_IPPTx functioning efficiently, a fast ionization gauge was developed to investigate the neutral gas pressure profiles to seek the critical time when the thruster is ignited. The gauge was calibrated for argon by using a capacitance manometer. Time-resolved pressure profiles have been acquired in the condition of the gas puff mass matching with the discharge energy and the drive coil parameters of the NUDT_IPPTx. It is demonstrated that the gas injector can supply a gas puff with a sufficiently steep（dp/dt？≈？770 kPa s-1） leading and trailing edge, and the gas puff can be compressed against the drive coil as expected. The critical ignition moment is considered to appear at some instant between 525 μs and 650 μs after the valve trigger.
文摘Based on the features and requirements of gas drainage system, an optimized explosion resistance technology is done after a comprehensive analysis and research about the triple IR （Infrared Ray） flame detection technology, explosion resistance valve technology and explosion resistance control technology. An intelligent PLC （Programmable Logic Controller） resistance control system is designed which can cut offthe gas branch quickly and accurately, and the controller have automatic pressure maintaining function, valve rotation limit function, remote and local control interlock function. The reliability and rationality of explosion resistance technology is verified by gas pipeline explosion propagation and resistance simulation test. Overall response time of explosion resistance system is less than 100ms, and the spread of fire in gas pipeline can be prevented effectively.
基金Supported by the Science Foundation of Tsinghua University
文摘This paper studies the nonlinear variable structure control (VSC) technique for designing power system integrate control systems which include an excitation controller and fast valve controller.A new method is applied to find nonlinear switching surface in deriving the control strategy.The responses to various large perturbation are simulated.The simuulation results show that the nonlinear VSC technique for integrated control systems can considerably improve the transient stabilization limitation of power systems and improve the dynamic properties of the generators.
