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In this paper, a new train of thought for the fault analyzing of the power transmission line is proposed. Firstly, the generalized state-space model of the power transmission line is built. Then based on the model, the power transmission line can be described as a first-order static physical system. Secondly, the internal description and external description of the static physical system of the line...
A fast power service restoration method for distribution network with DG is proposed in this paper. Firstly, a network simplification and multi-layer description method is presented. Secondly, on the basis of the network simplification and description, the studied restoration problem is analyzed equivalently in an equivalent calculating network and it is turned into a knapsack problem whose mathematical...
We report a high-power, high-efficiency Tm, Ho:YAlO3 (Tm, Ho:YAP) laser pumped by two laser diodes. The Tm (5 at.%) and Ho (0.5 at.%):YAP crystal is cut along the a axes, and the resultingcrystals are measured 4 × 4 × 8 mm3. The laser crystal is double end-pumped by two 18.0-W fiber-coupled laser diodes at 793.6 nm, and the output power of the Tm, Ho:YAP laser is 13.8W in continuous wave (CW) mode...
Conventional surveying method could not solve the problem of detecting building's whole deformation in a short time, including in particular flatness and inclination values of the surface of the building. Aiming at this problem, this paper introduce a method to solve it based on terrestrial laser point cloud, first step is fitting point-cloud datum to point-cloud model for reducing random errors in...
The wide spread use of power electronic equipment causes serious current harmonics in electrical power system. Harmonic currents that flow in the electrical power system would cause extra copper loss and immature operation of over current protection devices. Voltage distortion due to harmonic voltage drop in the electrical power distribution system impairs the operation of voltage-sensitive equipment...
We report a tunable mid-infrared optical parametric oscillator (OPO) using a single ZnGeP2 (ZGP) crystal with the cut-angle of 51.4°. A 17.0-W Q-switch Tm,Ho:GdVO4 laser is pumped by 800-nm LDs to generate 2.05-µm radiation, which have been used for pumping a angle-tuned ZGP OPO to generate mid-IR tunable from 5.84 to 7.87 µm. A 1.90-W idler output power has been acquired at 7.06 µm with 17.0-W pump...
Nowadays, with the growing development and application of Distributed Generation (DG), the proportion of DG in Distribution Network (DN) becomes an increasingly large. Traditional power service restoration strategies for DN have no consideration for the introduced DG, as a result they cannot be directly used in the Distribution Network with Distributed Generation (DNDG). In this paper, a novel network...
Omni-directional wheelchairs are capable of providing great help for users with difficult walking as wish. In order to help the users with problems controlling wheelchairs with physical contact methods, this paper presents a set of algorithms including improved classification and regression tree (CART), cross validation separation(CVS) and relative angle model (RAM) to control a wheelchair with eye...
Nowadays, electric wheelchairs on the market mostly were controlled by joystick which required users to operate by hands flexibly. But this wheelchair cound not be used by patients with hand disability or paraplegics. This paper designs an electric wheelchair controlled by eye movements. An eye tracker of Tobii is connected with a electric wheelchair. The eye tracker of Tobii is used to convert eye...
A circular metasurface that consists of twelve gradually increasing two-sided metallic grooves and an ultra-thin flexible dielectric film is theoretically and experimentally demonstrated based on the s poof surface plasmon polaritons (SSPPs) in the microwave frequency. The dispersion characteristics of the SSPPs structure are analyzed by the length of grooves study. The circular metasurface provides...
When terrestrial laser point-cloud data are employed for monitoring the façade of a building, point-cloud data collected in different phases cannot be used directly to calculate the deforming displacement due to data points in a homogeneous region caused by inhomogeneous sampling. Aiming at this problem, a triangular patch is built for the previous point-cloud data, the distance is measured between...
Microgrid is an effective means to integrate distributed generations and manage their power flows. Since the high penetration rate of DGs in microgrid and its capability to operate in grid-connected mode or islanded mode, the fault patterns of microgrid are not that obvious as those shown in the traditional low voltage distributed networks. Thus an extensive knowledge of fault transient characteristics...
As more and more DGs plugged into low voltage side of the distribution network, the low voltage distribution network has been changed to active distribution network. Bidirectional power flow and uncertainty of DGs' output cause the conventional fault location methods to be inapplicable in active distribution network for malfunction and miss trip, which makes the fault location in low voltage active...
When GPR is used for sub-bottom survey, the echo signal not only contains very high frequency, but also lasts for only several nanoseconds. These are the two difficulties in GPR signal sampling. Meanwhile, the step system which is responsible for the data sampling has an inherent minimum transmission delay. This delay will cause the failure of data collecting. In this paper, a new type of step system...
Condition-based maintenance technology plays a significant role in improving the equipment maintenance efficiency and reducing the equipment failure rate. Graphics model analysis is the basic technology for implementing condition-based maintenance. In this paper, based on graphics model analysis for the grid equipment condition-based maintenance, the ideas, methods and issues about carrying out condition-based...
The identification of clutter is an important method to mitigate its influences on radar target detection and Doppler centroid provide an effective feature to identify the moving or static clutter. However, Doppler estimation accuracies closely related to the length of the coherent processing intervals(CPI), and the Doppler centroid estimation in a small CPI is challenging. In this study we analyzed...
The turbulence clutter may appear in the radar real detecting surrounding from seasons to seasons. The turbulence clutter has motion and Doppler shift. Furthermore, it is normally densely distributed but the single turbulence is small and similar to the target, so that it may cause serious influence on the target detection. This paper proposes a novel method for the identification of turbulence clutter...
Flywheel energy storage system (FESS) can be used in reducing the negative effects caused by output fluctuation of renewable energy. But due to the confinement from rotor material, motor and unit building cost, FESS with a single flywheel module could not achieve the required MW power level so as to function properly in the power grid. By connecting the flywheel modules in parallel, a flywheel array...
This paper presents a new de-noising method for GPR image based on BEMD and wavelet. This method complies with the adaptability from BEMD. The method decomposes the image into a series of IMF components, then applies wavelet threshold de-noising on the selected high frequency IMF components for de-noising. In the reconstruction course, the de-noising IMF and low frequency IMF are combined. The experiment...
As we all known that complicated system is too difficult to be identified. A system designed here may be expected to get good control effects. Firstly, grey state modeling and modal decomposition is proposed. Secondly, an approach to modal control, which is to control the complicated system's behavior is designed. The applicable field of modal control systems is rather far and wide especially for...
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