Advanced Materials Research Vols. 971-973

Abstract: In order to solve the existing automatic fire alarm system shortcomings, such as high rate of false positives and poor reliability, this paper introduces an intelligent fire alarm system in the composition of MCU based on the CAN bus technology. The system, with the control core of STM32F103, uses multiple sensor information fusion technology to realize the fire warning, and adopts the advanced CAN bus technology to realize efficient, reliable and economic connections between the sensor and the fire linkage. Practice shows that the system is of high real-time, accuracy, and can meet the requirements of fire control in buildings.

Abstract: Many successful applications for the online monitoring of the insulation condition for electric power transformers have been reported over last thirty years. However, false or unsolved alarms have been quite frequently generated by those condition monitoring systems. Failures and some occasionally catastrophic accidents involving transformers have still occurred. A highly reliable insulation condition online monitoring and real-time alarm system has been developed, to help resolve these problems. An electric power transformer has strongly linked mechanical, electrical, magnetic, chemical and thermal characteristics, and is also directly linked to circuit breakers and generators. Team Intelligence (TI) was employed to integrate all the monitoring modules of the various different aspects of the transformer into one unique system. This system could also be integrate with the condition monitoring systems of various linked facilities, such as the monitoring systems of the turbine and the generator in a Optimal Maintenance Information System for Hydropower Plant (HOMIS). Highly reliable monitoring and real-time alarms of transformer insulation condition could be achieved, due to highly coordinated and rapid response features. This system has been deployed in several hydropower plants. The industrial application examples are demonstrated.

Abstract: Critical clearing time index is one of the indices to assess transient voltage stability. At present it is mainly calculated based on the instantaneous value after transient voltage instability or the steady state valueafer fault clearing time. So a new method to estimate the critical clearing time is presented which is correspongding to the induction motor minimum slipvalue in the fault. It can forecasttransient voltage instability,and has higher precision comparing whithquik criterion and analytical method. The simulation results of IEEE 30-bus system verify the effectiveness of the stated method. .CLC number: TM 73 Document code: A Article ID: 000-3673(2013)00-0000-00

Abstract: The permeability of the shale reservoir is nanoDarcy. After fracturing the fractures that appear in the shale reservoir are very complex, which can’t be described by conventional method. The conventional flow instrument for the fractures is improved. A more applicable flow chamber is remade to evaluate the flow conductivity of the network-like fractures more accurately. The model of the network-like fractures includes the marble and high-intensity proppants.

Abstract: In this paper, a new portable digital instrument is developed to measure the frequency, rms voltage, rms current and harmonic of power grid. Three phase voltage and current are sensed with precise transformer and then processed by signal conditioning unit before sampling. Synchronous AC sampling technique is introduced to avoid leakage effect of FFT. Consequently, frequency estimation, rms measurement and harmonic estimation are achieved based on MSP430. The experiment results indicate that this analyzer provides accurate frequency estimates with error in the range of 0.001Hz and amplitude estimates with error in the range of 0.1%, which can meet the need of offline application.

Abstract: In order to make a novel green design, the modified remaining rectangle layout method based on Bottom-Left algorithm and genetic algorithm is proposed, the area of photovoltaic modules laying on the surface of the roof can be maximized automatically by computer. The best laying diagram is shown; the best inverters are chosen considering both efficiency and price; the photovoltaic modules and inverters connection scheme which meets the requirements is shown.

Abstract: Springback of sheet forming is became a serious issue which we must be solved before froming process. The springback system was designed by visual studio2010, and displayed by OSG graphic developed tools. Besides, the system named Comsystem also used some FEM files from PAM-STAMP2G code. These files are put into Comsystem , then the working surface is formed and a new forming die is designed. The vector compensation algorithm and compensation factor have been used. The method to determine the second compensation factor is proposed. The system has great significance not only in controling the springback compensation but also in reduceing the production cost.

Abstract: The sphere slot is a 3D configuration of solid rocket motor (SRM) grain. Accompanied with multi-design-variable and strong constraints, its optimization is always a complicated problem. In this article, a methodology has been presented for the optimization of sphere slot grain configuration. Parameterized CAD model method and unsteady lumped parameter internal ballistic model are adopted to evaluate the performance of sphere slot grain to establish the optimization objective and constraint functions. An improved differential evolution algorithm incorporated with Oracle penalty function method is developed and applied on the optimization to solve global optimum solution converging difficulty of multi-variable constrained problem. The approach is validated by a small sphere slot SRM. The results illustrate it is effective method and has robustness and efficient capacity to explore the design space for global optimum solution of sphere slot grain.

Abstract: Considering the current situation that the temperature control systems in market have the general disadvantages of complicated structure, high power consumption and tremendous cost, a new greenhouse temperature supervising system is designed, with a Arduino Mega 2560 single chip microcomputer as the core, XBEE as the short distance wireless transferring tools, and with function of displaying information in computers and remote control. The core component of this system is the Arduino software-hardware open source platform, which is currently popular in the market. This platform embraces the excellence of stability, low power consumption, cheap cost and easy operation as its advantages and selling points. XBEE can constitute the mesh network, each module of which can supplied as the route node, coordinator and terminal node. This system can achieve the functions of collecting data from sensors while is capable of displaying these data in the computers and put them under the network remote control. Easy to install, it can simultaneously achieve network monitoring several greenhouses. Enormous convenience to production inside the greenhouse is fulfilled due to these mentioned features as well, which makes it suitable to the small scale agricultural production.

Abstract: this paper mainly analysis ship motion state in rough sea, to analysis rolling and pitching of the ship in the storm of regular wave, analyzing different waves in different situations .