A coaxial multi-gap multi-channel spark switch with stainless-steel-spring ring gap electrodes is designed and investigated. The switch is triggered by a pulse applied to the cylindrical electrode outside the discharg...A coaxial multi-gap multi-channel spark switch with stainless-steel-spring ring gap electrodes is designed and investigated. The switch is triggered by a pulse applied to the cylindrical electrode outside the discharging channel through a parasitic capacitance coupling. The jitter of the switch is reduced by several short-distance gas gaps in series, and its inductance is reduced by a multi-channel discharge on account of the inductance isolation between the coils of the spring ring electrode. The experimental results indicate that the switch is of low inductance (15-30 nH), low jitter (-3 ns), and stable breakdown展开更多
We numerically solve the time-dependent Ginzburg–Landau equations for two-gap superconductors using the finite-element technique. The real-time simulation shows that at low magnetic field, the vortices in small-size ...We numerically solve the time-dependent Ginzburg–Landau equations for two-gap superconductors using the finite-element technique. The real-time simulation shows that at low magnetic field, the vortices in small-size samples tend to form clusters or other disorder structures. When the sample size is large, stripes appear in the pattern. These results are in good agreement with the previous experimental observations of the intriguing anomalous vortex pattern, providing a reliable theoretical basis for the future applications of multi-gap superconductors.展开更多
The trigger characteristics of a multi-gap gas switch with double insulating layers,a square-groove electrode supporter and a UV pre-ionizing structure are investigated aided by a high sensitivity fiber-bundle array d...The trigger characteristics of a multi-gap gas switch with double insulating layers,a square-groove electrode supporter and a UV pre-ionizing structure are investigated aided by a high sensitivity fiber-bundle array detector, a UV fiber detector, and a framing camera, in addition to standard electrical diagnostics. The fiber-bundle-array detector is used to track the turn-on sequence of each electrode gap at a timing precision of 0.6 ns. Each fiber bundle, including five fibers with different azimuth angles, aims at the whole emitting area of each electrode gap and is fed to a photomultiplier tube. The UV fiber detector with a spectrum response of 260-320 nm,including a fused-quartz fiber of 200 μm in diameter and a solar-blinded photomultiplier tube, is adopted to study the effect of UV pre-ionizing on trigger characteristics. The framing camera,with a capacity of 4 frames per shot and an exposure time of 5 ns, is employed to capture the evolution of channel arcs. Based on the turn-on light signal of each electrode gap, the breakdown delay is divided into statistical delay and formative delay. A decrease in both of them, a smaller switch jitter and more channel arcs are observed with lower gas pressure. An increase in trigger voltage can reduce the statistical delay and its jitter, while higher trigger voltage has a relatively small influence on the formative delay and the number of channel arcs. With the UV pre-ionizing structure at 0.24 MPa gas pressure and 60 kV trigger voltage, the statistical delay and its jitter can be reduced by 1.8 ns and 0.67 ns, while the formative delay and its jitter can only be reduced by 0.5 ns and 0.25 ns.展开更多
A multi-gap and multi-channel gas switch with convexo-convex discal planet electrodes was designed and investigated.Eight gaps are formed in series by a trigger electrode,six intermediate electrodes and two high volta...A multi-gap and multi-channel gas switch with convexo-convex discal planet electrodes was designed and investigated.Eight gaps are formed in series by a trigger electrode,six intermediate electrodes and two high voltage electrodes with a uniform gap length of 5 mm.The self breakdown and triggered breakdown performance of the switch are reported.Both the delay time and jitter decrease with the increase in the trigger voltage,switching coefficient and the decrease in the trigger isolating resistor.The delay time of the switch is about 40 ns,and the jitter is less than 2 ns when charged with±85 kV and triggered by a voltage pule of-75 kV.The inductance of the switch is about 30 nH.展开更多
双母管式机组较为广泛地应用于热电联产机组中,但由于多炉多机和2根大容量母管互相影响,导致热电负荷跟踪不及时,母管压力控制自动化水平较低。为此,针对双母管系统的非线性、强耦合、大迟延特性,设计了基于广义扩张状态观测器的多模型...双母管式机组较为广泛地应用于热电联产机组中,但由于多炉多机和2根大容量母管互相影响,导致热电负荷跟踪不及时,母管压力控制自动化水平较低。为此,针对双母管系统的非线性、强耦合、大迟延特性,设计了基于广义扩张状态观测器的多模型预测控制(generalized extended state observer based muti-model predictive control,GESOMMPC)方法。首先,建立了基于间隙度量(gap-metric)的多模型控制对象用于逼近非线性系统;其次,设计了扩张状态观测器估计系统耦合的集总扰动,并作为前馈信号输入到预测控制器中;最后,设计基于扰动前馈的多模型预测控制器实现对双母管系统的控制。实验结果表明,相对于PID方法,所提方法在满足电热负荷的同时,可以在允许范围内保持母管压力稳定,且动态偏差更小,过渡过程时间更短。展开更多
随着电力系统中可再生能源(renewable energy sources,RESs)比例不断增加,新能源参与能量市场和备用市场在技术上和经济上的重要性不断凸显。研究了含有风、光、水、储资源的RES聚合商在日前市场、备用市场及实时平衡市场等多个市场的...随着电力系统中可再生能源(renewable energy sources,RESs)比例不断增加,新能源参与能量市场和备用市场在技术上和经济上的重要性不断凸显。研究了含有风、光、水、储资源的RES聚合商在日前市场、备用市场及实时平衡市场等多个市场的综合竞价策略。针对北欧顺序交易市场框架,提出了一套考虑备用资源和波动补偿耦合的数据驱动信息间隙理论(data-driven information gap theory,DIGDT)决策模型解决RES聚合商的多阶段竞价优化问题。在DIGDT中采用基于置信区间的模糊集构造方法(confidence interval-based ambiguity set,CIAS)估计风、光的预测误差,通过机会约束对水电和储能(batteryenergy storage,BES)补偿出力偏差的可能性进行建模,并考虑备用资源与补偿容量的多时间尺度耦合。在备用市场中,利用基于备用调用场景的随机优化确保日前备用计划的可行性。通过案例分析验证了所提出模型的有效性。展开更多
Continuous wave(CW) high current proton linacs have wide applications as the front end of high power proton machines. The low energy part of such a linac is the most difficult and there is currently no widely accepted...Continuous wave(CW) high current proton linacs have wide applications as the front end of high power proton machines. The low energy part of such a linac is the most difficult and there is currently no widely accepted solution. Based on the analysis of the focusing properties of the CW low energy proton linac, a 10 Me V low energy normal conducting proton linac based on equidistant seven-gap Cross-bar H-type(CH) cavities is proposed. The linac is composed of ten 7-gap CH cavities and the transverse focusing is maintained by quadrupole doublets located between the cavities. The total length of the linac is less than 6 meters and the average acceleration gradient is about1.2 Me V/m. The electromagnetic properties of the cavities are investigated by Microwave Studio. At the nominal acceleration gradient the maximum surface electric field in the cavities is less than 1.3 times the Kilpatrick limit,and the Ohmic loss of each cavity is less than 35 k W. Multi-particle beam dynamics simulations are performed with Tracewin code, and the results show that the beam dynamics of the linac are quite stable, the linac has the capability to accelerate up to 30 m A beam with acceptable dynamics behavior.展开更多
基金This work was supported by the National Natural Science Foundation of China, Grant No. 10035020
文摘A coaxial multi-gap multi-channel spark switch with stainless-steel-spring ring gap electrodes is designed and investigated. The switch is triggered by a pulse applied to the cylindrical electrode outside the discharging channel through a parasitic capacitance coupling. The jitter of the switch is reduced by several short-distance gas gaps in series, and its inductance is reduced by a multi-channel discharge on account of the inductance isolation between the coils of the spring ring electrode. The experimental results indicate that the switch is of low inductance (15-30 nH), low jitter (-3 ns), and stable breakdown
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11564003 and 11865005)the Natural Science Foundation of Guangxi Province of China(Grant No.2018GXNSFAA281024)。
文摘We numerically solve the time-dependent Ginzburg–Landau equations for two-gap superconductors using the finite-element technique. The real-time simulation shows that at low magnetic field, the vortices in small-size samples tend to form clusters or other disorder structures. When the sample size is large, stripes appear in the pattern. These results are in good agreement with the previous experimental observations of the intriguing anomalous vortex pattern, providing a reliable theoretical basis for the future applications of multi-gap superconductors.
基金supported by National Natural Science Foundation of China(No.11105109)
文摘The trigger characteristics of a multi-gap gas switch with double insulating layers,a square-groove electrode supporter and a UV pre-ionizing structure are investigated aided by a high sensitivity fiber-bundle array detector, a UV fiber detector, and a framing camera, in addition to standard electrical diagnostics. The fiber-bundle-array detector is used to track the turn-on sequence of each electrode gap at a timing precision of 0.6 ns. Each fiber bundle, including five fibers with different azimuth angles, aims at the whole emitting area of each electrode gap and is fed to a photomultiplier tube. The UV fiber detector with a spectrum response of 260-320 nm,including a fused-quartz fiber of 200 μm in diameter and a solar-blinded photomultiplier tube, is adopted to study the effect of UV pre-ionizing on trigger characteristics. The framing camera,with a capacity of 4 frames per shot and an exposure time of 5 ns, is employed to capture the evolution of channel arcs. Based on the turn-on light signal of each electrode gap, the breakdown delay is divided into statistical delay and formative delay. A decrease in both of them, a smaller switch jitter and more channel arcs are observed with lower gas pressure. An increase in trigger voltage can reduce the statistical delay and its jitter, while higher trigger voltage has a relatively small influence on the formative delay and the number of channel arcs. With the UV pre-ionizing structure at 0.24 MPa gas pressure and 60 kV trigger voltage, the statistical delay and its jitter can be reduced by 1.8 ns and 0.67 ns, while the formative delay and its jitter can only be reduced by 0.5 ns and 0.25 ns.
基金supported by National Natural Science Foundation of China(Nos.50477019,50637010)the State Key Laboratory of Electrical Insulation and Power Equipment of China(EIPE.09207)
文摘A multi-gap and multi-channel gas switch with convexo-convex discal planet electrodes was designed and investigated.Eight gaps are formed in series by a trigger electrode,six intermediate electrodes and two high voltage electrodes with a uniform gap length of 5 mm.The self breakdown and triggered breakdown performance of the switch are reported.Both the delay time and jitter decrease with the increase in the trigger voltage,switching coefficient and the decrease in the trigger isolating resistor.The delay time of the switch is about 40 ns,and the jitter is less than 2 ns when charged with±85 kV and triggered by a voltage pule of-75 kV.The inductance of the switch is about 30 nH.
文摘双母管式机组较为广泛地应用于热电联产机组中,但由于多炉多机和2根大容量母管互相影响,导致热电负荷跟踪不及时,母管压力控制自动化水平较低。为此,针对双母管系统的非线性、强耦合、大迟延特性,设计了基于广义扩张状态观测器的多模型预测控制(generalized extended state observer based muti-model predictive control,GESOMMPC)方法。首先,建立了基于间隙度量(gap-metric)的多模型控制对象用于逼近非线性系统;其次,设计了扩张状态观测器估计系统耦合的集总扰动,并作为前馈信号输入到预测控制器中;最后,设计基于扰动前馈的多模型预测控制器实现对双母管系统的控制。实验结果表明,相对于PID方法,所提方法在满足电热负荷的同时,可以在允许范围内保持母管压力稳定,且动态偏差更小,过渡过程时间更短。
文摘随着电力系统中可再生能源(renewable energy sources,RESs)比例不断增加,新能源参与能量市场和备用市场在技术上和经济上的重要性不断凸显。研究了含有风、光、水、储资源的RES聚合商在日前市场、备用市场及实时平衡市场等多个市场的综合竞价策略。针对北欧顺序交易市场框架,提出了一套考虑备用资源和波动补偿耦合的数据驱动信息间隙理论(data-driven information gap theory,DIGDT)决策模型解决RES聚合商的多阶段竞价优化问题。在DIGDT中采用基于置信区间的模糊集构造方法(confidence interval-based ambiguity set,CIAS)估计风、光的预测误差,通过机会约束对水电和储能(batteryenergy storage,BES)补偿出力偏差的可能性进行建模,并考虑备用资源与补偿容量的多时间尺度耦合。在备用市场中,利用基于备用调用场景的随机优化确保日前备用计划的可行性。通过案例分析验证了所提出模型的有效性。
基金Supported by National Natural Science Foundation of China(11375122,91126003)
文摘Continuous wave(CW) high current proton linacs have wide applications as the front end of high power proton machines. The low energy part of such a linac is the most difficult and there is currently no widely accepted solution. Based on the analysis of the focusing properties of the CW low energy proton linac, a 10 Me V low energy normal conducting proton linac based on equidistant seven-gap Cross-bar H-type(CH) cavities is proposed. The linac is composed of ten 7-gap CH cavities and the transverse focusing is maintained by quadrupole doublets located between the cavities. The total length of the linac is less than 6 meters and the average acceleration gradient is about1.2 Me V/m. The electromagnetic properties of the cavities are investigated by Microwave Studio. At the nominal acceleration gradient the maximum surface electric field in the cavities is less than 1.3 times the Kilpatrick limit,and the Ohmic loss of each cavity is less than 35 k W. Multi-particle beam dynamics simulations are performed with Tracewin code, and the results show that the beam dynamics of the linac are quite stable, the linac has the capability to accelerate up to 30 m A beam with acceptable dynamics behavior.
