Advanced Materials Research Vols. 765-767

Abstract: A novel algorithm based on background modelling and active contour model is proposed for moving object edge detection. Firstly, it uses the background modeling to complete moving object detection, then it uses quad-tree decomposition method to contain the corresponding to the foreground image, through the data distribution density of the sparse matrix, calculates the seed points corresponding to the regions which are containing the moving object. Finally, starting from these seed points, it executes the active contour model in parallel to complete the multiple moving objects edge detection. Experimental results show that the proposed algorithm can effectively obtain the object outlines of multi-moving objects and the edge detection results are close to the judgment of the human visual, parallel contour extraction makes our algorithm has good real-time.

Abstract: Based on the small scale power system frequency fluctuation frequency leakage problems due to the FFT phase measurement error problem, this paper presents a high accuracy algorithm for phase difference measurement based on windowed discrete Fourier transform, the signal truncated using 4 order Blackman-Harris window, and corrects the phase correction method for discrete spectrum thus to calculate the phase difference. The algorithm for phase difference measurement theory and signal frequency independent, so there is no need to sample the signals of the whole cycle. A simple algorithm, less calculation, high precision, has strong inhibition on the harmonic and noise, simulation results verify the feasibility and effectiveness of the algorithm.

Abstract: Fire detection based on images is an effective method for fire prevention, especially in big room or badly environment. It is important to extract the features of a flame image. According to the idea of visual saliency in computer vision, saliency model of brightness, color and flame texture are proposed here. The saliency of flame brightness is indicated by the V component in HSV color space. The saliency of flame color is expressed by the relation of R and B in the RGB color space. The saliency of flame texture is described by the distance between the feature vectors which are the combination of features with Local Binary Pattern. Experimental results show the saliency model is effective for flame feature extraction.

Abstract: In the engineering application, we put forward higher request to the device in the clock accuracy and stability. In this paper, we can modify GPS second pulse online which based on the GPS timing and combine high precision crystal in order to reduce its random error. And on this basis, we put forward a method of dynamic compensation to do the real-time numerical compensation in the apparatus. It can be used as accurate information for the device using nanosecond, not only has high precision, but also simple to implement, and has higher application value in engineering.

Abstract: The piezoelectric ceramic transformer has the advantages of high conversion efficiency, high pressure, electromagnetic compatibility,etc.It overcomes the shortcomings of large electromagnetic interference, low conversion efficiency , a large volume, etc. Using IR2184,the paper designs piezoelectric ceramic transformer full-bridge driver circuit. It greatly improves the conversion efficiency of the power system and power.

Abstract: The paper take the solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) as the object, studies the influence of the fuel cell on load characteristics of the distribution network. Structures based on Matlab simulation platform contains the SOFC typical distribution network, and a series of transient simulation was conducted, results indicate that the SOFC power generation system can be describe in its equivalent model based on the URL equivalent circuit-order differential equation of state. On this basis, the access to the distribution network SOFC power generation system regarded as power consumption of the negative dynamic load, proposed containing the SOFC can be to the equivalent the GSLM model containing the SOFC described distribution grid load characteristics.

Abstract: In this paper, a highly-selective filter based on the composite right/left-handed transmission line (CRLH-TL) theory is presented .It is realized by replacing the traditional shunt inductive loading with a series LC resonator to ground. An attenuation-pole can be introduced by replacing the shorted-stub with a open stub.Simulation using ADS and HFSS of a compact highly-selective filter demonstrated the viability of the approach.

Abstract: In view of the current direct supply situation of our coal mines high voltage distribution networks commonly used 6kV or 10kV electric cables,on the base of describing mechanism of three different neutral point grounded of underground high voltage distribution networks,detailed analysising three different grounded way of high-voltage power grid parameter sensitivity of leakage protection. The results show that, mine the sensitivity of the high-voltage grid leakage protection and start zero-sequence voltage have a great relationship, the greater the zero-sequence voltage setting value, the device's ability to detect leakage faults weaker corresponding lower sensitivity.

Abstract: The transfer characteristics of current transformers (CT) change due to DC bias, which directly impacts the accuracy of measurement and power metering. Based on equivalent circuit models and core magnetizing characteristic, qualitatively analysis current transformer saturation increase errors of CT. Transfer errors under DC bias and remnant flux are also obtained based on J-A model of CT in PSCAD/EMTDC and full-wave Fourier algorithm to show that the ratio error and phase displacement increase with the DC bias. Based on FFT spectrum analysis to identify remnant flux and DC bias provides scientific basis for error compensation of CT.

Abstract: Designed based on bi-directional DC / DC converter of the super-capacitor and battery hybrid energy storage system, using both on the technical performance have strong complementary features that can improve the battery charge and discharge process, so that the battery charge and discharge cycles decrease, prolong the service life of battery. In matlab/simulink environment, established a system simulation model, the result showed that the hybrid energy storage system can effectively restrain the DC bus voltage fluctuations, make the output voltage relatively stable.