共查询到20条相似文献，搜索用时 250 毫秒
1.
SHORT CIRCUIT CURRENT LIMITER IN AC NETWORK 总被引：13，自引：0，他引：13
ＩＮＴＲＯＤＵＣＴＩＯＮＳｈｏｒｔｃｉｒｃｕｉｔｉｎｐｏｗｅｒｓｙｓｔｅｍｓｉｓａｓｅｒｉｏｕｓｆａｕｌｔ,ｗｈｉｃｈｍａｙｄａｍａｇｅｔｈｅｅｑｕｉｐｍｅｎｔｉｎｔｈｅｓｙｓｔｅｍ .Ｉｔｒｅｑｕｉｒｅｓｔｈｅｐｒｏｔｅｃｔｉｏｎｓｙｓｔｅｍｔｏｓｗｉｔｃｈｏｆｆｔｈｅｖｅｒｙｈｉｇｈｌｅｖｅｌｏｆｆａｕｌｔｃｕｒｒｅｎｔ.Ｔｈｅｔｒａｄｉｔｉｏｎａｌｍｅｔｈｏｄｔｏｌｉｍｉｔｔｈｅｓｈｏｒｔｃｉｒｃｕｉｔｃｕｒｒｅｎｔｌｅｖｅｌｉｓｔｏｓｅｒｉａｌｌｙｃｏｎｎｅｃｔａｌｉｍｉｔｉｎｇｒｅ ａｃｔ… 相似文献
2.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｉｎｒｅｃｅｎｔｙｅａｒｓ,ｍａｎｙｎｅｗｐｏｗｅｒｓｗｉｔｃｈｉｎｇｓｅｍｉｃｏｎｄｕｃｔｏｒｓｈａｖｅｅｍｅｒｇｅｄｄｕｅｔｏｔｈｅｒａｐｉｄｄｅｖｅｌｏｐｍｅｎｔｏｆｐｏｗｅｒｅｌｅｃｔｒｏｎｉｃｓ.Ｉｔｉｓｎｏｔｓｔｒａｎｇｅｔｈａｔｔｈｅｍｏｄｅｌｏｆａｎｅｗｌｙｄｅｖｅｌｏｐｅｄｄｅｖｉｃｅｃａｎｎｏｔｂｅｆｏｕｎｄｉｎｔｈｅｌｉｂｒａｒｙｏｆａｃｉｒｃｕｉｔｓｉｍｕｌａｔｏｒ.Ｔｈｅｕｓｅｒｓｈａｖｅｔｏｅｓｔａｂｌｉｓｈｔｈｅｓｉｍｕｌａｔｉｏｎｍｏｄｅ… 相似文献
3.
Xu Shiyi 《上海大学学报(英文版)》1998,2(4):279-283
ｅｇｒａｔｉｏｎ ＣｉｒｃｕｉｔTX１ＩｎｔｒｏｄｕｃｔｉｏｎＯｆａｌｔｈｅｔｅｓｔｇｅｎｅｒａｔｉｏｎａｌｇｏｒｉｔｈｍｓ,ｒａｎｄｏｍｔｅｓｔ－ｉｎｇｉｓａｎｅｆｉｃｉｅｎｔａｎｄｃｏｓｔ－ｅｆｅｃｔｉｖｅｔｅｓｔｍｅｔｈｏｄｆｏｒｐｒｏｄｕｃｔｉ... 相似文献
4.
Wang Wenqi Wang Rongguang Chen Baolin Wang Tong 《上海大学学报(英文版)》1998,2(3):213-217
１ＩｎｔｒｏｄｕｃｔｉｏｎＡｃｔｉｖｅｄｅｖｉｃｅｓｐｌａｙａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｍｏｎｏｌｉｔｈｉｃｍｉｃｒｏｗａｖｅｉｎｔｅｇｒａｔｅｄｃｉｒｃｕｉｔｓ（ＭＭＩＣｓ）．Ｆｏｒｍｅｒｌｙ,ｔｈｅｄｅｐｌｅｔｉｏｎｍｏｄｅＧａＡｓＭＥＳＦ... 相似文献
5.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ ＴｈｅｓｐａｔｉａｌＧｒｅｅｎ’ｓｆｕｎｃｔｉｏｎｓｏｆｍｕｌｔｉ ｌａｙｅｒｅｄｍｅｄｉａａｒｅｕｓｅｆｕｌｉｎａｎａｌｙｓｉｓｏｆａｎｔｅｎｎａａｎｄｉｎｔｅｇｒａｔｅｄｃｉｒｃｕｉｔｓｔｒｕｃｔｕｒｅｓ.Ｔｈｅｙａｒｅｃｏｎｓｔｒｕｃｔｅｄｉｎｔｗｏｓｔｅｐｓ.ＴｈｅｆｉｒｓｔｉｓｔｏｄｅｒｉｖｅｔｈｅｓｐｅｃｔｒａｌＧｒｅｅｎ’ｓｆｕｎｃｔｉｏｎ .ＴｈｅｓｅｃｏｎｄｉｓｔｏｍａｋｅｉｎｖｅｒｓｅＦｏｕｒｉｅｒｔｒａｎｓｆｏｒｍｏｆｔｈｅＧｒｅｅｎ’ｓｆｕｎｃ ｔ… 相似文献
6.
ＩＮＴＲＯＤＵＣＴＩＯＮＡｎｉｎｔｅｇｒａｔｅｄｃｉｒｃｕｉｔ (ＩＣ)ｉｎｆｏｒｍａｔｉｏｎｓｙｓ ｔｅｍｓｔｏｒｅｓＩＣｄａｔａｉｎｉｔｓｄａｔａｂａｓｅ .ＴｈｉｓｇｒｅａｔｌｙｂｅｎｅｆｉｔｓＩＣｄｅｓｉｇｎｅｒｓｂｙａｌｌｏｗｉｎｇｔｈｅｍｔｏｂｒｏｗｓｅｏｒｑｕｅｒｙｖａｒｉｏｕｓＩＣｉｎｆｏｒｍａｔｉｏｎｌｉｋｅｌｏｇｉｃｆｕｎｃ ｔｉｏｎｓ,ｐａｃｋａｇｅｔｙｐｅｓ,ｐｉｎｄｅｓｃｒｉｐｔｉｏｎｓ,ｔｅｃｈｎｉ ｃａｌｐａｒａｍｅｔｅｒｓ,ｐｒｏｄｕｃｅｒｉｎｆｏｒｍａｔｉｏｎａｎｄｔｙｐｉ… 相似文献
7.
ＩＮＴＲＯＤＵＣＴＩＯＮＶａｒｉｏｕｓｔｙｐｅｓｏｆｓｕｒｇｅａｂｓｏｒｂｅｒｓｔｏｐｒｏｔｅｃｔｖａｒｉｏｕｓｌｏｗ ｖｏｌｔａｇｅｅｌｅｃｔｒｉｃａｌｃｉｒｃｕｉｔｓｆｒｏｍｔｒａｎ ｓｉｅｎｔｏｖｅｒｖｏｌｔａｇｅｉｎｃｌｕｄｅ :( 1 )ｇａｓｄｉｓｃｈａｒｇｅｔｕｂｅ (ｇａｓｅｏｕｓｇａｐ) ,( 2 )ｖａｒｉｓｔｏｒｓ,( 3)ｓｅｍｉ ｃｏｎｄｕｃｔｏｒＴＶＳ (ｔｒａｎｓｉｅｎｔｖｏｌｔａｇｅｓｕｐｐｒｅｓｓｏｒ) .Ｅａｃｈｔｙｐｅｈａｓｉｔｓａｄｖａｎｔａｇｅｓａｎｄｄｉｓａｄｖａｎｔａｇｅｓ.Ｇａ… 相似文献
8.
ZHANG Qi XIE Guo dong 《上海大学学报(英文版)》1999,3(4):299-303
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｈｉｇｈｐｏｗｅｒｆａｃｔｏｒｉｎｄｕｃｔｉｏｎｍｏｔｏｒｗｉｔｈｆｌｏａｔｉｎｇｗｉｎｄｉｎｇｉｎｐａｒａｌｌｅｌｃｏｎｎｅｃｔｉｏｎｗｉｔｈｃａｐａｃｉｔｏｒｓｉｓａｍｏｔｏｒｏｆｓｐｅｃｉａｌｓｔｒｕｃｔｕｒｅａｎｄｗｉｔｈｓｐｅｃｉａｌｃｏｎｎｅｃｔｉｏｎ．Ｉｔｓｓｔａｔｏｒｃｉｒｃｕｉｔｃｏｎｆｉｇｕｒａｔｉｏｎ［１］ｉｓｓｈｏｗｎｉｎＦｉｇ．１．Ｆｉｇ１ｓｈｏｗｓｔｗｏｓｅｔｓｏｆｓｔａｔｏｒｗｉｎｄｉｎｇｓ,ｔｈｅｐｏｗｅｒｗｉｎｄｉｎｇｓｃｏｎｎ… 相似文献
9.
黎锡强 《上海大学学报(英文版)》2000,4(2)
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｔｈｅｓｐｕｔｔｅｒｉｎｇｔｅｃｈｎｉｑｕｅｗｅｌｌｓｕｉｔｓｔｈｅｇｒｏｗｔｈｏｆｃｏｍｐｏｕｎｄｓａｎｄａｌｌｏｙｓ ,ｗｈｏｓｅｅｌｅｍｅｎｔａｌｃｏｎｓｔｉｔｕｅｎｔｓｈａｖｅｓｉｇｎｉｆｉｃａｎｔｌｙｄｉｆｆｅｒｅｎｔｍｅｌｔｉｎｇ ｐｏｉｎｔｓａｎｄｖａｐｏｒｐｒｅｓｓｕｒｅｓ.ＡｃｏｎｓｉｄｅｒａｂｌｅａｍｏｕｎｔｏｆｗｏｒｋｓａｂｏｕｔｒｆｓｐｕｔｔｅｒｄｅｐｏｓｉｔｉｏｎｏｆｂｉｎａｒｙⅢ Ⅴｃｏｍｐｏｕｎｄｆｉｌｍｓｈａｓｂｅｅｎｐｕｂｌｉｓｈｅｄ[1～… 相似文献
10.
《上海大学学报(英文版)》2000,(4)
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｔｈｅｇｒｏｗｔｈｏｆｅｌｅｃｔｒｉｃｐｏｗｅｒｃｏｎｓｕｍｐｔｉｏｎｈａｓｒｅ ｓｕｌｔｅｄｉｎａｎｉｎｃｒｅａｓｅｏｆｆａｕｌｔｃｕｒｒｅｎｔ.Ｉｎｓｏｍｅｃａｓｅｓ ,ｔｈｅｆａｕｌｔｃｕｒｒｅｎｔｓｅｖｅｎｅｘｃｅｅｄｔｈｅｒａｔｅｄｂｒｅａｋｉｎｇｃａ ｐａｃｉｔｙｏｆｔｈｅｉｎｓｔａｌｌｅｄｃｉｒｃｕｉｔｂｒｅａｋｅｒｓａｎｄｔｈｅｃｕｒｒｅｎｔｗｉｔｈｓｔａｎｄｉｎｇｌｅｖｅｌｏｆｏｔｈｅｒｅｑｕｉｐｍｅｎｔ[1] .Ｆｕｒｔｈｅｒ ｍｏｒｅ ,ｗｉｔｈｔｈｅｄｅｖ… 相似文献
11.
lintroductionInrecent20years,owingtotilerapiddevelopnlentofco.nputertechnology,tiletiniteelenlent1netnodforstndyingelectronlagneticfieldwasdevelopedti.onltheoreticalconlputationtoconnnercialsoftwarepackageinvestigation,towardstiledirectionofCAD,andgradnan… 相似文献
12.
INTRODUCTIONMostcountrieshaveimplementednewpoli ciesontheenergysavingandenvironmentpro tection.AmericanPresidentBushsigned“TheComprehensiveNationalEnergyPolicyAct”in1992statingthatnogeneral purpose ,three phaseinductionmotorswillbeallowedintoUnit edStat… 相似文献
13.
For an energy-efficient induction machine, the life-cycle cost (LCC) usually is the most important index to the consumer.
With this target, the optimization design of a motor is a complex nonlinear problem with constraints. To solve the problem,
the authors introduce a united random algorithm. At first, the problem is divided into two parts, the optimal rotor slots
and the optimization of other dimensions. Before optimizing the rotor slots with genetic algorithm (GA), the second part is
solved with TABU algorithm to simplify the problem. The numerical results showed that this method is better than the method
using a traditional algorithm.
Project (No. 601299) supported by the Science Foundation of Hebei Province, China. 相似文献
14.
The grating eddy current displacement sensor （GECDS） for distance or position measurement used in watertight electronic calipers was described. The sensor relies on repetitive variation of inductance against displacement caused by the change of coupling areas between moving coils and static reflectors. The investigations focused on setting up and utilizing a computer model of the 3D eddy current fields and geometry to analyze causes of the production of measurement blind areas, and to investigate effects of the sensor parameters, such as axial gap between coils and reflectors, reflector length and reflector width on characteristics of the sensor. Simulation results indicated that the sensor has the smallest nonlinearity error of 0.15%, which agrees well with the experimental results. 相似文献
15.
李俊华 《常熟理工学院学报》2009,23(8):83-85
在单自由度磁悬浮系统中,为了得到转子的稳定悬浮,必须由系统中的位移传感器提供转子的准确位置信息．这就要求对传感器测得的电压信号进行处理,这些信号在很大范围内是非线性的,从而限制了其测量范围．为了使转子在大范围内稳定悬浮,需要对传感器的信号作线性处理．本文根据所测得的电涡流位移传感器的特性曲线,用软件补偿的方法对此传感器进行了线性补偿,从而扩大了传感器的线性范围．实践表明,用此方法对传感器线性补偿后,转子的稳定悬浮范围扩大很多． 相似文献
16.
This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite element method, taking into account the nonlinear characterization and the eddy current loss of the magnetic material. The experiment and simulation results agree well and show that the prototype actuator can produce a force of±100 N with the maximum power being 7 W and has linear characteristics with a positive magnetic stiffness within a stroke of ±1 mm. Its non-linearity is less than 1.5% and the hysteresis less than 1.5%. The actuator＇s frequency response （-3 dB） of the displacement reaches about 15 Hz, and the most significant factor affecting the dynamic performance is identified as the eddy current loss of the magnetic material. 相似文献
17.
In this paper, a stabilized finite element technique, actualized by streamline upwind Petrov-Galerkin (SUPG) stabilized method
and three-step finite element method (FEM), for large eddy simulation (LES) is developed to predict the wind flow with high
Reynolds numbers. Weak form of LES motion equation is combined with the SUPG stabilized term for the spatial finite element
discretization. An explicit three-step scheme is implemented for the temporal discretization. For the numerical example of
2D wind flow over a square rib at Re=4.2×105, the Smagorinsky’s subgrid-scale (SSGS) model, the DSGS model, and the DSGS model with Cabot near-wall model are applied,
and their results are analyzed and compared with experimental results. Furthermore, numerical examples of 3D wind flow around
a surface-mounted cube with different Reynolds numbers are performed using DSGS model with Cabot near-wall model based on
the present stabilized method to study the wind field and compared with experimental and numerical results. Finally, vortex
structures for wind flow around a surface-mounted cube are studied by present numerical method. Stable and satisfactory results
are obtained, which are consistent with most of the measurements even under coarse mesh. 相似文献
18.
This paper proposes an analysis and a direct power control （DPC） design of a wind turbine driven doubly-fed induction generator （DFIG） under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions. 相似文献
19.
The passive electromagnetic damper has the same configuration as that of the electromagnetic bearing, but no sensors and no closed loop control are needed. Its robustness and no-contact structure are its great advantages. When the rotor vibrates, the electromagnetic field intensity in the air gap is altered, then fluctuating currents in the damper coils and eddy currents inside the surface layer of rotor are created. Damping force is caused by the fluctuating currents, while retardation torque is generated by eddy currents. The characteristics of a damper may be improved by adding an additional electrical circuit. Numerical studies showed that damping coefficient increases with increasing static current, but decreases with increasing frequency. And the damping coefficient of the improved damper at higher frequency is more evident than that of the original damper. Experimental results showed that the resonant vibration around the first critical speed was obviously suppressed by both types of passive electromagnetic damper. 相似文献
20.
基于冲突图模型形成的二进制整数规划,提出了一种蜂窝网络中支持D2D通信的无线资源分配方法．首先,提出一种频率资源分配算法,即为每个D2D链路都分配一个频率资源块．分配频率资源时将尽可能地利用蜂窝网络中的无线频率资源空间重用机会．然后,提出一种时隙调度算法,即为所有分配同一频率资源块的D2D链路进行时隙资源调度．调度时隙资源时将保证使用同一频率资源块的D2D链路之间达到长期平均吞吐率的比例公平．通过计算机仿真对所提出方法的性能进行了验证,结果表明该方法能够在蜂窝网络中实现D2D通信功能． 相似文献