Applied Mechanics and Materials Vols. 347-350

Abstract: The characteristics and the design factors of wireless sensor network node are talked in this article. According to the design factors of wireless sensor network, this article will mainly point out the design of wireless sensor nodes based a Cortex-M3 Microcontroller STM32F103RE chip. And the wireless communication module is designed with a CC2430 chip. Our wireless sensor node has good performance in our test.

Abstract: This paper gives the research on the anti-noise AM spot jamming performance of pseudo-random binary code phase modulation and sine FM combined fuze based on the criterion of signal to jamming ratio gain. First, the overall signal to jamming ratio gain of its receiver is reduced in detail under the noise AM spot jamming, then, the factors affecting anti-jamming performance are analyzed. The results show that the PRBC-SFM combined fuze has stronger performance of anti-noise AM spot jamming, and its anti-jamming performance can be improved effectively by choosing the parameters of the n-th order Bessel function, and along with decreasing periods and narrowing code width, Doppler frequencys influence on the anti-noise AM spot jamming performance of the PRBC-SFM combined fuze is debased.

Abstract: Aiming at the incompleteness and uncertainty of information existing in power system fault diagnosis, a new fault diagnosis approach based on Bayesian network is proposed in this paper. Through the Bayesian network of structure learning and parameter learning, a power system fault diagnosis model based on Bayesian network has been proposed. Conditional probability table describes the connection degree between various factors in quantity. Diagnostic results of instance proved the effectiveness and superiority of the proposed method.

Abstract: Power grid is a complicated and huge system, many links are involved during its life-cycle, and serious information exchange and sharing problems can be found between these links, they restrict the level of power grids informatization construction. With the presentation of building information modeling (BIM) and the application of IFC standard, the research for building different life cycle stages of information exchange and sharing is strongly pushed forward as well as gained good results. The successful application of BIM in construction business provides great chance for grid whole life data information integration and sharing. After intensively studying every links business and data characteristics of power grid, cooperated with the BIM theory, this paper comes up with a method that applies BIM theory into power system data integration and sharing, with an electric power data integration platform construction scheme based on BIM, by which grid full life cycle of data integration and sharing problem can be successfully solved.

Abstract: An imaging system based on the transmission and reflection modes in the terahertz (THz) region is developed by using a backward-wave oscillator (BWO) as source, a Golay-Cell as detector, and an oscilloscope as data acquisition unit. The system software based on the oscilloscope is designed to control the object movement, and the capture and display of the continuous THz wave image data. The imaging of different objects is tested at the frequencies of 450 GHz and 890 GHz to show the validity of the imaging system at room temperature. The influence of objects humidity and thickness, incident wavelength, and translation step on the THz imaging is discussed in details.

Abstract: Fourier algorithm can be effective utilized in the Microcomputer relay protection to filter out Harmonic component in the AC signal .but the drawback is that not filter attenuation DC component. it may be affect the computation accuracy of the entire system .and it is also reduce the efficiency of the system. In this paper ,we combined with the actual project ,on the basis of analysis of the full-wave Fourier algorithm ,for the problem of it can not filter decaying a periodic component ,we proposed an improved algorithm, and combined with MATLAB simulation ,the results show that the improved algorithm has the advantages of high accuracy and the algorithm is simple. In the microcomputer relay protection of the power system need to handle all kinds of signals, provide the necessary information for the implementation of protection. however, With the rapid development of computer technology and the continuous research of computer algorithms, a lot of actual power system protection device has been widely used in our life, on the one hand, these devices reduce the complexity of building hardware circuit, on the other hand ,it can make full use of the filter function about some algorithms have itself. The most important is that it can avoid the problem of instability and low efficiency with some filter circuit. But, this characteristic need the algorithms has a high precision ^[2,3]. The algorithm is set up in the microcomputer protection is a mathematical model for achieve some specific function. and write the corresponding computer applications according to this model. Then do some specific mathematical operations with these digital signals will achieve the purpose of protection. At present, the widely used full wave Fourier algorithm has a function of filtering DC component and harmonic component^[4],but it can not filtering the decaying DC component in the system. It will be cause a certain interference and influence to the whole system in the practical application, the result is that led to the precision of the operation drop and lose the meaning of the protecting. In this paper, combined with specific engineering example give an improved calculation method. Through example of simulation has proved that using this algorithm can accurately figure out fundamental component and harmonic component, and it has the advantage of algorithm simple and high accuracy ^[5].

Abstract: As to the output current of grid inverter in high-power wind power generation system contains large current harmonic, the solution is to introduce the LCL filter to replace the typical inductance filter in grid inverter, which brings instability to the system, thus the control strategy is to use the grid inverter current indirect control combined with the grid voltage feed forward compensation. A 15KW wind power simulation platform is constructed. The experimental results show that the grid converter can run stably, and also have a better dynamic and static performance.

Abstract: In this paper, we focus on modeling, oscillatory stability analysis of the drive train system and the transient performances of wind turbine with doubly fed induction generator (DFIG) wind turbines, which are evaluated under sub-synchronous operation during the grid voltage fault. Results have shown that the oscillatory stability and shafting parameters have a close relationship, it is necessary to consider the drive train system while the transient performances of DFIG wind turbines are analyzed.

Abstract: This article describes a system device capable of displaying a car outside sounds, the system device sound signals collected by the sound sensor , combined with the single-chip analytical processing Finally, LED lights, buzzer and other electronic actuator smart car external speaker sound source direction and strength of the drivers are able to accurately determine the rear of the vehicle the location and intentions, in order to take more appropriate driving route and speed, so that the operation of the vehicle more intelligent, is conducive to maintaining the smooth flow of traffic, more effective in reducing traffic accidents, to further improve automotive safety system, greatly improves the safety performance of vehicles.

Abstract: In the security monitoring system, in order to realize the multi-angle and different positions of the camera monitoring the camera monitoring, a pan tilt zoom (PTZ) module is used. This paper describes the PELCO-D protocol of PTZ and serial communication firstly. Then it achieves control the of PTZ and lens work based on Windows VC++. Finally, It discusses the main function of the system structure and coding.