Advanced Materials Research Vols. 971-973

Abstract: This paper uses Isight_FD 5.6 to integrate UG8.0 parametric modeling, ANSYS Workbench static analysis, modal analysis, and mathematical modeling of design optimization, by means of optimization algorithm, to meet strength and the stiffness of the tower, to realize the optimization of tower structure, so as to attain the expected target which reduces the weight of tower.

Abstract: The principle through the turbine flowmeter,establish a relationship between the flow rate measurement of Coaxial phase water detector,calculate the actual measurement accuracy,and for several factors affect the accuracy of experiments were carried out,obtained the pattern of flow measurement.

Abstract: Buckling Restrained Brace, Abbreviated as BRB in thefollowing content, a new omponent dissipating energy and absorbing quake ,as itis installed steel constrained unit to prevent overall instability ,it can notonly maintain its stiffness and stability, but also dissipate seismic energy bythe steel core material, as a result we can protect the main structure of thebuilding. This paper focuses on the buckling restrained braced frame (BRBF) ofthe energy principle、calculation method and thespecific design process.

Abstract: In this article, through the simulated experiment, the fire risk of copper conductors which were in arcing earth fault of low-voltage were validated. As a result, it showed that the polyporous combustibles could be ignited easily while ignited probability of the tight combustibles were slim under the same arcing earth fault; meanwhile, the ignited probability of the polyporous combustibles were almost identical under the different arcing fault. The results aimed to provide the important references for exploring the fire scene and investigating the reasons of electric fires once the relevant evidences existed.

Abstract: In order to search the pointing accuracy degradation and the wheel-rail contact of the National astronomical observatory 50m radio telescope, according to the actual wheel-rail structure and design indicators, the wheel rail contact problem with the finite element analysis based on non-Hertz rolling contact theory is analyzed. The results show that the maximum deformation should be less than 1 mm. Then the measurement scheme of rail horizontal error and deformation is formulated. The mean value of the rail horizontal error is 2.89mm, while the maximum rail horizontal error is 1.5mm. The rail maintenance scheme is put forward after the flaw detection which finds large areas of cracks at the rail junction and the welded joint. The measurement is taken after rail maintenance; the experimental data coincide with the simulation results and then verify the correctness of the wheel-rail contact model, also the solution scheme of rail cracks. The reason for the pointing accuracy degradation is verified finally, which also can provide an effective method for the wheel-rail design and maintenance of large radio telescope.

Abstract: Automatic voltage control(AVC) is the highest form of current power grid voltage and reactive power control,during the implementation of AVC, the whole network reactive power optimization isthe core and foundation. Thispaper researches and discuses the application of reactive power optimization inpower grid AVC. In the traditional reactive power optimization, the reactivepower limits of synchronous generators are fixed. In this paper, thesynchronous generator PQ operating limits change with external conditions,thus establishes reactive power optimization model in accordance with therequirements of AVC. Thispaper presents reactive power optimization method based on the principle ofpartition. The method decomposes the system to several partitions. Eachpartition separately optimized, thus reduces the system scale.And the convergence of the algorithm, the calculation speed and the discretevariable processing etc. improve. At the same time, this method reflects theclassification, hierarchical, partition, characteristics of coordinated controlof AVC.

Abstract: In order to implement Ergonomics analysis uesd the model of Chinese Minors 2D body template in the design process. Model 2D body in Creo has been studied, According to human dimensions of Chinese minors. Detailed illustrate the process and precautions of model 2D body template in Creo, Using 2D templates inspect the Ergonomics issue in school desks and chairs as a case study.

Abstract: Because of China's energy and load imbalance, large-scale long-distance power transmission becomes inevitable. Under this background , series compensation capacitor in the power system and HVDC developed rapidly, and the SSO (Sub-synchronous oscillations) caused by HVDC is becoming increasingly apparent. Fundamental reason of SSO lies in the sub-synchronous system negative damping characteristics, so it is necessary to analyze the system damping characteristics. The net system damping includes mechanical and electrical damping. Based on small-signal test method-complex torque coefficient method in the time-domain simulation , paper analyzed the system electrical damping and mechanical damping characteristics.

Abstract: Although drilling and blasting method is widely used to excavate tunnel structures, it has great effect on adjacent ground structures. In order to find out the influence sphere and features of this construction method on overpass, three-dimensional numerical simulation method was used to analyze the displacement, stress and blasting vibration velocity of overpass. The results show that: (1) Drilling and blasting excavation method can cause differential settlement of stratum and overpass which is above the crown of tunnel. (2) The strong constraint structures of overpass are obviously affected by blasting vibration than other parts. (3) It should be taken extra protection measures at connection points between piers and decks as well as connection points between piers and stratum. (4) Horizontal vibration velocity caused by blasting excavation is lower than vertical vibration velocity. To control the vertical blasting vibration velocity is the essential to control the security of tunnel structure and upper structures. The above results certainly contribute to construct tunnel structures by using drilling and blasting excavation under complicated conditions.

Abstract: the safety of power grid scheduling is the key to ensure the safe and stable operation of power grid. Scheduling work dangerous point analysis, formulate measures, strengthen precontrol is important means to ensure the safety of power grid. Introduces the analysis of the dispatching work dangerous points and preview. This paper expounds the main work and status quo of power system dispatching operation management, and puts forward solutions.