Analysis of brushless three-phase synchronous generator without exciter

Recently, a demand for small-capacity generators has been increasing as electric sources in small ships and automobiles or as portable electric sources driven by engines. It is desired that the structure of small-capacity generators be simple and robust, and that the generators be highly reliable, easily maintained and controlled. This paper describes an analysis of the original brushless synchronous generator without exciter. The output voltage can be adjusted in the wide range by controlling the stator dc current. To analyze the characteristics of this generator, the finite element method is applied. It is found that the results of theoretical analysis agree well with the experimental results.     

Quantitative evaluation of generator power control effect of FACTS controllers for power system stabilization

The advancement of power electronics technologies has significantly developed the power system stabilizing controllers. Quantitative as well as qualitative evaluation of their effectiveness in power systems is a matter of great importance for the feasibility investigation of these apparatus. In this paper, the possible control region of FACTS controllers with series and/or shunt configuration in a single machine to infinite bus system is formulated in the powerangle curve with a set of algebraic equations. The effectiveness of TCPST (Thyristor‐Controlled Phase Shifting Transformer), SSSC (Static Synchronous Series Compensator), and TCSC (Thyristor‐Controlled Series Compensator) for the improvement of the transient stability is evaluated quantitatively as a numerical example. The correctness of the proposed method has been confirmed by analysis based on the electromagnetic transients simulation with a detailed system model. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 43–51, 2002     

Stability of large-scale coal-fired MHD channels

Stability of large-scale coal-fired MHD channels is studied by (1) linearized stability analysis, and (2) time-dependent 1-D analysis. The channel length is 15 m with 600 electrode pairs, and the output power ranges from 220.6 MW through 258.7 MW. Linearized stability analyses show that the Faraday channels operated with fixed loading resistance are stable, whereas the two waves of u and u–a (u, a: gas and sound velocity) become unstable in the Faraday channel with fixed loading factor. Two waves of u and u–a are unstable in the diagonal channel with fixed loading current and the u + a wave becomes unstable in the diagonal channel with fixed electrode current. Time-dependent one-dimensional analyses indicate that the Faraday channels with fixed load resistance are smooth without growth of fluctuation. The diagonal channels with fixed electrode current are smooth with no fluctuation, though the linear theory indicates that the u + a wave is unstable. The diagonal channel with fixed load current suffers large disturbance along the latter half of the channel, being consistent with the linearized analysis which indicates that the u - a and u waves are unstable.     

Fuzzy logic for signal prediction in nuclear systems

In this paper, we present a fuzzy logic-based algorithm which allows to build a predictive model of an evolving signal. The if-then rules are inferred from the available input-output data. The errors of the model predictions with respect to the measured plant signals can then be used to detect, in real-time, any deviation of the process due either to a component's failure or to an operator's action. Applications of the approach are presented with respect to a chaotic time series of literature and to the water level in the steam generator of a PWR.     

50MW发电机定子绕组接地保护设置探讨

结合50MW发电机定子绕组接地保护的设计，探讨如何完善定子绕组接地保护的设置，并提出详细的改进方案。     

永磁发电机定转子扫膛故障分析

针对阳光发电公司 3#永磁发电机定转子扫膛故障 ,分析了其发生的原因 ,介绍了处理方法和对策     

燃气开环磁流体发电机的研制

介绍了磁流体发电的原理,设计制造了燃气开环磁流体发电机的实验样机。阐述了实验样机的结构和功能,总结了样机设计的要点。     

Synthesis of single-walled carbon nanotubes by arc-vaporization under high gravity condition

Arc-vaporization is one of the common methods to synthesize single-walled carbon nanotubes (SWNTs). However the detailed synthesis mechanism is still not clear, and the synthesis of longer and chirality-selected SWNTs has not been obtained. Here influence of the gravity G = 1 g₀, 2 g₀, and 3 g₀ is studied in order to develop the synthesis method of SWNTs. Simultaneously, calculations of heat convection are also carried out by using a fluid simulation program and the results are compared with the experimental results.     

600 MW国产发电机检修全过程管理与工艺探讨

以嘉兴电厂4台600MW国产发电机的检修为基础,介绍了国产600MW发电机的检修全过程管理和检修工艺,针对不同国内厂家制造的发电机存在的结构差异,指出了检修中需要注意的事项。     

1.5MW永磁直驱风力发电机几个问题探讨

介绍了1.5 MW低速直驱永磁风力发电机的新型整体机座结构,磁极、空心轴、轴承和润滑的结构形式,该型电机经受了风电场运行考验,安全可靠。