Advanced Materials Research Vols. 433-440

Abstract: The course of has a broad engineering background, with rigorous theory and strong logic. This paper discusses the applications and features in the dynamic circuit for the zero-input response, impulse response and step response. Using superposition theory gets the expression result for the impulse response and step response on the basis of zero-input response. And have a detail solution for the typical examples using the knowledge of higher mathematics, focusing on the introduction of the phasor method, Laplace transform to deal with circuit analysis problems. This method has some guiding significance for solving the different circuit.

Abstract: As important parts of airship’s control systems, the attitude control and station-keeping control have important effects on the vehicle’s performance. This article discusses the control methods in present usage, which include PID control, robust control, optimization control, sliding mode variable structure control, auto-disturbance rejection control and other control methods. The application areas of the methods are discussed, and the developing direction is pointed at last. Introduction

Abstract: This paper proposed an approach for a control, which fuzzy logic method was designed and used in the refrigeration system based on the summary of the common control methods on electronic expansion valve (EEV) and variable speed compressor(VSC). The experiment had been carried out, that showed the fuzzy logic controller achieve more stable superheat and water temperature values against to a disturbance and had good energy saving potential.

Abstract: GPS common-view is the main method for the time and frequency remote transfer currently, of which the uncertainty can reach several nanoseconds. The GPS P3 code receiver has recently become one of the international research hotspots, which can improve the comparison accuracy by revising ionosphere delay real-time values observed at two frequencies. In order to test the accuracy of the GPS Common-view comparison system, two EURO-160 receivers and a SEPT POLARX2 receiver constitutes the zero-baseline Common-view comparison experiment. The test result of experiment shows that the common-view system can reach the accuracy of 2~3ns, which is better than the single-frequency receivers. This system can present better time & frequency transfer services.

Abstract: Car styling design has become the important factors of car products sales and car distinctive styling is also the important competition means of car enterprises under the globalization trend. For car styling design, this paper expounds the 3D morphing technology. The technology of the computer automatically generate different from the existing car, can not only shorten the design cycle, and also can provide a lot of stylist designs and car styling design, styling division of material, The technology is a good supplement of recent car styling design technologies for innovation.

Abstract: The produce causation and the development direction of the distributed power and the far-reaching meaning of constructing China characteristic Smart Grid are introduced in this paper. The influence to the traditional transmit electricity net protection under the background of the distributed power being connected on a large scale and the emphases attention technic problems are analysed emphatically. The tiny net technic is explored, which is the main method of the distributed power connection and bring into play its efficiency. Finally, the development aim of the Smart Grid protect system is prospected.

Abstract: According the radial flutter extension structure problems in commonly used fire alarm system, a novel topology structure of fire alarm systems based-on holographic crystal forms was proposed. It was composed of multiple devices, including intelligent fire detectors, which can communicate with each other, record fire information and judge, alarms, security, evacuation lights etc. Each device can record all of the information so as to form the hologram. These devices on each floor level in buildings and decorated with vertical layout in the staircase, so that fire alarm system topology based-on holographic crystal forms was set up. The systems can ensure the normal operation of other devices in case that central control equipment failed in extreme cases. And then the automatic fire safety equipment continued to automatically control fire rescue and guide the staff in the correct escape route. Moreover, when a device or a line goes wrong, only failure equipment or system was cut off line, and others were still able to keep communications. Compared with other methods, this new system does not affect the normal equipment of the work.

Abstract: This paper presents correlation analysis to discriminate the magnetizing inrush current from the fault currents in transformers. The proposed technique is based on the normalized correlation coefficient flowing into transformers during the fault current or the transformer inrush current. The method need the imaginary parts of fundamental frequency components, which are obtained from sampling differential current based on full-wave fourier algorithm and half-wave fourier algorithm, then calculate the normalized correlation coefficient with theory of correlation coefficient. Theoretical analysis and dynamic simulation results show that the method is effective and reliable under various fault conditions and simple to be applied.

Abstract: Empirical mode decomposition (EMD), which is the core mechanic of the Hilbert-Huang transform(HHT), is a local, fully data driven and self-adaptive analysis approach. It is a powerful tool for analyzing multi-component signals. Aiming at the reduction of scale mixing and artificial frequency components, an improved scheme was proposed for analysis and reconstruction of nonstationary and multicomponent signals. The improved EMD method uses the wavelet analysis method and normalized correlation coefficient to deal with the problems. Because the inrush current is a peaked wave with nonstationary component, a new algorithm based on improved EMD is presented for fast discrimination between inrush current and fault current of power transformers. Theoretical analysis and dynamic simulation results show that the method is effective and reliable under various fault conditions and simple to be applied.

Abstract: A new scheme for fault identification during power swings is proposed in this paper. The new scheme is based on the orthonormal wavelet transform algorithm. The main advantage of the proposed scheme is that different types kinds of fault of the transmission line can be correctly identified from different types of the fast power swings. Also, the faults during power swings can be identified from the power swings with the proposed scheme without any time delay. Furthermore, the problem whether the protection should trip or not immediately for the distance protection is discussed in the paper. Test results with the data sampled from EMTP verify the effectiveness of the proposed scheme. Furthermore, another advantage of this algorithm is that it can be realized for the real-time applications with finite real calculation.