This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connecte...This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. It can response the order within 1 ms. When fault occurs, the switch closes and the capacitors are bypassed, and the fault current is limited by the reactor. Simulation analysis and experiment show that the electromagnetic repulsion force actuator can meet the demand of fast closing switch, it is feasible to develop the FCL with low cost and high reliability.展开更多
A new type of fault current limiter (FCL) with series compensation based fast-closing switch is proposed. It is composed of a capacitor bank and a reactor in series. The main control component is a fast-closing switch...A new type of fault current limiter (FCL) with series compensation based fast-closing switch is proposed. It is composed of a capacitor bank and a reactor in series. The main control component is a fast-closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. When fault occurs, the switch closes and bypasses the capacitors, and the fault is limited by the reactor then. Simulated analysis and experiments show that it is feasible to develop the FCL with low cost and high reliability. The effectiveness of transient stability for power system is evaluated by digital simulation.展开更多
The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control sy...The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.展开更多
目的探讨使用便携式超声仪应用创伤重点超声评估（focused assessment with sonography for trauma，FAST）检查法快速诊断海战腹部闭合伤方面的应用价值。方法模拟伤病员40名（随机抽取中方人员36名，马方人员4名），分别使用便携式彩...目的探讨使用便携式超声仪应用创伤重点超声评估（focused assessment with sonography for trauma，FAST）检查法快速诊断海战腹部闭合伤方面的应用价值。方法模拟伤病员40名（随机抽取中方人员36名，马方人员4名），分别使用便携式彩色超声仪应用FAST检查法判断伤病员腹腔各问隙是否存在游离液体和固定大型彩色超声诊断仪对腹腔各脏器进行常规超声检查判断是否存在腹腔脏器损伤，记录两种检查方法所用检查时间，并进行统计学分析。结果使用便携式超声仪FAST检查法检查伤病员均未发现腹腔游离液体，检查耗时15．6～58．6s，平均（32．21±11．74）s；固定式超声仪常规检查方法检查伤病员共发现肝囊肿5例，胆囊息肉4例，肾囊肿5例，前列腺钙化灶7例，均未发现腹腔脏器损伤，检查耗时97．7～149．5s，平均（118．21±18．29）s，两者检查耗时差异有统计学意义（P〈0．01）。结论便携式超声仪应用超声FAST检查法可快速评估腹部闭合损伤伤情，为下一步诊疗赢得宝贵时间，提高伤员的救治率，适合在作战舰艇部队医疗卫生部门积极推广普及。展开更多
文摘This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. It can response the order within 1 ms. When fault occurs, the switch closes and the capacitors are bypassed, and the fault current is limited by the reactor. Simulation analysis and experiment show that the electromagnetic repulsion force actuator can meet the demand of fast closing switch, it is feasible to develop the FCL with low cost and high reliability.
文摘A new type of fault current limiter (FCL) with series compensation based fast-closing switch is proposed. It is composed of a capacitor bank and a reactor in series. The main control component is a fast-closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. When fault occurs, the switch closes and bypasses the capacitors, and the fault is limited by the reactor then. Simulated analysis and experiments show that it is feasible to develop the FCL with low cost and high reliability. The effectiveness of transient stability for power system is evaluated by digital simulation.
基金supported in part by the ITER Program of China(973 Program)(No.2011GB109002)National Natural Science Foundation of China(No.11275056)
文摘The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.
文摘目的探讨使用便携式超声仪应用创伤重点超声评估（focused assessment with sonography for trauma，FAST）检查法快速诊断海战腹部闭合伤方面的应用价值。方法模拟伤病员40名（随机抽取中方人员36名，马方人员4名），分别使用便携式彩色超声仪应用FAST检查法判断伤病员腹腔各问隙是否存在游离液体和固定大型彩色超声诊断仪对腹腔各脏器进行常规超声检查判断是否存在腹腔脏器损伤，记录两种检查方法所用检查时间，并进行统计学分析。结果使用便携式超声仪FAST检查法检查伤病员均未发现腹腔游离液体，检查耗时15．6～58．6s，平均（32．21±11．74）s；固定式超声仪常规检查方法检查伤病员共发现肝囊肿5例，胆囊息肉4例，肾囊肿5例，前列腺钙化灶7例，均未发现腹腔脏器损伤，检查耗时97．7～149．5s，平均（118．21±18．29）s，两者检查耗时差异有统计学意义（P〈0．01）。结论便携式超声仪应用超声FAST检查法可快速评估腹部闭合损伤伤情，为下一步诊疗赢得宝贵时间，提高伤员的救治率，适合在作战舰艇部队医疗卫生部门积极推广普及。
