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Due to the characteristic of flexible operation mode of distributed power, the fault current between grid connected and islanding way is very different, conventional three-section over-current protection isn't suitable for microgrid power system. A big challenge is brought forward for microgrid protection, to satisfy quick acting and selective requirement. A microgrid protection principle based on...
This paper firstly reviews the development history of power system protection, especially the wide area protection and control trending to integration in smart grid. It also descripts the features of adaptability and coordination in the integrated wide area protection control system. This multi-levels system is composed of the local intelligent electronic device, the high-speed communication network,...
In order to adapt the new policy of the retail side reform, the novel operating models of power retail are proposed for Chinese electricity retailing side reform based on analysis of different power marketing systems in the world. The key technologies for the distribution and utility integrating system are discussed to support the electricity retailing company, which include the planning & design,...
Relay protection is one of problems troubling the development of half-wavelength AC transmission technology. This paper modeled the half-wavelength line with the distributed parameter, researched the fault characteristics and the adaptability of phase-splitting steady current differential protection theoretically and through plenty of simulation work, and analyzed its influencing factors from three...
This paper is devoted to electromagnetic transient model and algorithm of inrush current and internal fault for power transformer. In the paper, it presents transformer model with excitation nonlinear characteristic based on the controlled source theory transformer simulation and damping trapezoidal algorithm. It simulates inrush current and internal fault by that model. When transformer inrush current...
In order to improve hardware utilization, a novel Protection & Control Architecture based on virtual devices in digital substation is proposed in this paper. An “all-in-one” monitoring and control device is developed to support new architecture. Based on a Cloud Computing platform, the protection and control functions are built as virtual devices. Based on virtual protection & control, the...
With the development of communication technology, a large number of intelligent substation has been constructed, substation area protection and wide area protection technology has been widely used. Then Protection Intelligent Center (PIC) taking over the main functions of multiple substations protection in the distribution network comes into being, making large-scale information centralized processed...
As the "12th Five year development plan" of China is in progress, the new energy industry and tertiary industry has been developing rapidly, which sets a higher requirement for the power distribution network. In the foreseeable future, the connecting topology of civilian distribution network would become too complicated to the current protection method based on local information. Therefore,...
With the increase of demand in power supply demand, increased strength of connection complexity and access of renewable energy, traditional current protection has been unable to meet the needs of the safe and reliable operation of distribution system. To prevent this, the cutting-current-based fault location searching algorithm is put forward in this paper using the single-end current vector. Firstly,...
There are more and more studies on centralized protection, but the effective protection scheme dealing with the information-missing of entire substation is scarce. To solve this problem, this paper proposes a wide area protection online adaptive algorithm. When the information of entire substation is missing and inter-station line fails, the algorithm will automatically collect current information...
Smart substation and communication technology have a tremendous development, making the grid to coordinate and optimize a wide range of data possible, thus providing a higher level of centralization foundation for the protection and control functions. Therefore, the direction of future's protection is based on the high-performance computer technology and advanced communication networks. To this end,...
Introduce the Protection Intelligent Center that suit the evolution tendency of the substation form, but the new form of substation is lack of corresponding description of information model, Based on IEC61850 defined SCL language, according to the characteristics of the Protection Intelligent Center, the paper put forward the structure of Protection Intelligent Center information model description...
EMS of microgrid (I-IEMS) is developed to monitor and control distributed generator (DG). It i s necessary t o research practical I-IEMS for large-scale multi-microgrid. Energy Management System for microgrid in this paper is based on Smart Grid Dispatching Technical Support System (SGDTSS) which has been widely used in dispatching system of provincial or regional power grid. The secure operating...
This paper proposes a new speckle reduction algorithm for synthetic aperture radar images; it is based on the adaptive neighborhood window (ANW) and rotationally invariant block matching (RIBM). Firstly, we introduce the RIBM into the despeckling method to calculate the block matching between small patches precisely; then, aiming at the limitation of the rectangle neighborhood window (RNW), we propose...
To efficiently preserve tiny details and sharpness information of synthetic aperture radar (SAR) images while clearly remove the speckles, an improved non-local means method is proposed. Firstly, aiming at the traditional patch-similarity measurement not precise using in SAR image, we define a new variable to obtain a more precise patch-similarity measurement results. Furthermore, the PDF mapping...
The time delay of echo generated by the moving target simulator based on digital delay technique is discrete. So there are range and phase errors between the simulated target and real target, and the simulated target will move discontinuously due to the discrete time delay. In order to solve this problem and generate a continuously moving target, this paper uses signal processing technique to adjust...
Aiming at the problem of the glowworm swarm optimization algorithm having low convergence speed and accuracy in the later period, a new glowworm swarm optimization algorithm with improved movement pattern (IMGSO) is presented that is based on adaptive step and global information. Depending on the effect of step size and the direction of movement on the convergence, IMGSO algorithm improves convergence...
In order to overcome the defects of traditional analog method to generate nanosecond impulse pulse, this paper designs a new full-digital and full-coherent source which is suitable for the generation of nanosecond impulse pulse according to signal theory and DDS theory. In order to generate sinc impulse whose spectrum is rectangular, two parameters which influence its spectrum and bandwidth are analyzed...
Considering the misclassification of conventional regional division based on gray level-average gray level-median gray level three-dimensional (3D) histogram, the result of 3D Otsu's method is not accurate enough. Its computing complexity rapidly increases due to the increment of another eigenvalue. Thus a fast iterative algorithm of the improved 3D Otsu's method is proposed. Based on the gray level-gradient...
This paper made a further research on the key technology of micro-grid transient stability control, and putted forward the distributed generations union scheduling Algorithm, that take the storage inverter control model as the core, Based on ultra-short-term forecasting of distributed generations output by means of BP neural network. It guaranteed micro-grid bus voltage to achieve “zero intermittent”...
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