Advanced Materials Research Vol. 977

Abstract: As a flexible AC transmission system equipment, controlled shunt reactor is becoming increasingly important in the grid with the development of EHV / UHV transmission systems. Since currently rated voltage of controlled shunt reactor has developed to 1100kV, as its capacity control system, or valve-control system, stability and reliability test is very important. In this paper, the test circuit and method for the valve-control system in the laboratory or the test station for combined adjustment test is put forward. By adjustment of power supply and the device parameter, the valve-control system can put the voltage and current of the device to be the same as the on-set operation. Actual test of the world's first 1100kV controlled shunt reactor valve-control system shows that, the test method in this paper is correct and feasible, and the objective of assessment can be achieved.

Abstract: For maximum wind power tracking, the adaptive fuzzy sliding mode control is designed based on the method of rotation speed feedback of brushless doubly-fed machine. The adaptive fuzzy system approaches the uncertainties of generation system. A nonlinear integrator sliding mode control strategy is proposed to track the speed of wind. The stability of closed-system is proved using Lyapunov’s method. Finally, the simulation studies are provided to confirm that the rotation speed of brushless doubly-fed machine can fast track the speed of wind. Then the maximum power-point tracking is gotten.

Abstract: Parking exposed to the sun brings about a pretty high temperature in the vehicle which irritates most people. In-vehicle temperature regulating system is designed to eliminate this inconvenience. It is composed of the Insulation Section and the Solar Power Cooling Section. The first part utilize the insulation materials to keep the moderate temperature of the instant when the owner leaves the vehicle. The second part uses the solar panels to generate electricity and then powers the semiconductor cooler to work. Thus the air in the vehicle can be kept at a lower and comfortable temperature. This paper theoretically calculates the temperature in the vehicle with and without the system respectively. The curve of temperature variation is described and contrasted with the measured results. A conclusion that this system can inhibit the temperature rise effectively is drawn.

Abstract: As one of the most important type of machinery, rotating machinery may malfunction due to various reasons. Sometimes the fault is a single one, but sometimes it maybe in multi-fault condition, this paper mainly focus on the latter. First, the paper gives a brief introduction of the study on multi-fault, then it introduces the mixture of Alpha stable distribution model, besides, it gives the model parameters estimation algorithm in detail, at last we use the SOM net to complete pattern recognition. The results prove that this modeling method is effective in multi-fault diagnosis in rotating machinery.

Abstract: The state of bubbles moving in water is a complicated process, during the rising process of the bubble, their shapes, flow and temperature state of the water will have a certain impact on their movement. The impacts of relevant factors are analyzed in this paper. Combined with experiments of bubbles moving in still water and moving water, velocity and temperature sensibility of the bubble are analyzed. Meanwhile, based on the summarizing the regularity of the bubbles rising. Theoretical guidance are provided to the new method of bubbles float measuring method.

Abstract: Numerical tests were conducted with six different pillar width to determine the optimal pillar width of the inclined coal seam based on the fracture and deformation characteristics. The results show that, the fracture zone in pillar is consistent when the pillar width is 3m, while the fracture zone is inconsistent when the pillar width is larger than 5m. When the pillar width is 3m, the pillar is completely fractured, and the shear fracture zone in pillar increase gradually with the pillar width ranges from 5m to 10m,. There has the smallest heaving floor when the pillar width is 5m, while the largest heaving floor when the pillar width is 10m. The reasonable pillar width is 5m.

Abstract: In order to improve the comprehensive technical and economic indicators of a double circular gear, based on the conjugate principle and design method of the double circular gear, by use of the modified differential evolution multi-objective optimization technique and MATLAB computer simulation technology, constrained multi-objective optimization design of a double circular gear was done. According to the research process and results, by use of the improved differential evolutionary multi-objective optimization technique, the design cycle of product can be shorten effectively, the design quality of product can be improved.

Abstract: In view of function needs for embedded network measurement control system,this paper presents a resolution scheme of wireless sensor gateway based on ARM11,The paper in-depth research hardware design of wireless sensor network node and software design, which is to realize communication between embedded gateway and Internet server by any of WIFI,GPRS,3G,IP. According to the corresponding communication protocol, the scheme applied to a variety of different occasions

Abstract: Numerical tests were conducted with six different pillar width to analyze the stress distribution of the inclined coal seam. The results show that, with the pillar width changes from 3m to 20m, the maximum stress surrounding tail entry of coal face 3506 is always gradually shift from down side to up side and the reasonable pillar width should be less than 7m.

Abstract: A fire occurred in the steel framed building could be yielded an unexpected disasters including loss of human lives and damages of properties. Therefore, to evade the tragedies from the building, fire resistance performance of structural elements is required and specified into each nation’s building regulation. Especially, the structural beam plays a key role to transfer the load applied on the floor to column. In this study, to estimate the fire resistance performance of structural beam made of SM 400, analysis using not only mechanical, thermal properties at high temperature of the SM 400 but theories of heat transfer and thermal stress were conducted. The result of this study showed that as the lengths of beam are increased, the structural stability become getting worse. Therefore, it is not recommended to use the same thickness of fire protective materials derived from prototype’s length, 4100 mm to longer beam.