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Distributed generation units in the microgrid are intermittent and random, which can't meet the demand of grid power stability. In this paper, hierarchical control strategy is used to research hybrid storage system: the superstratum is the microgrid central management and control system, and it contains both distributed generation units and load requirements; the lower layer is the local control system...
The structure and working principle of hybrid energy storage system are introduced. The classical RC model of ultracapacitor is analyzed, and the topology of charging and discharging converter of energy storage system is studied. A ultracapacitor-battery hybrid energy storage system model based on bidirectional boost-buck circuit is constructed, and the charging and discharging process of the energy...
Supercapacitor, as a new type of energy storage device, has broad application prospect in the power system and others. It is very significant to establish an accurate model to reflect the actual job characteristics for supercapacitor reasonable use, performance optimization and system simulation. This article summarizes all kinds of supercapacitor model, points out the characteristics of the existing...
In order to optimize the operation status of hybrid energy storage system in electric vehicles, a novel fuzzy logic control strategy is proposed. This strategy adopts Kalman filtering algorithm to estimates state of charge (SOC) and state of power (SOP), which can calculate the optimum power and alleviate the errors of SOC effectively. Besides, the framework of the strategy and the model of both battery...
As for permanent magnet synchronous motor, permanent magnet flux is constant, this article analyzes the d-q axis PMSM model, applies voltage space vector pulse width modulation technology (SVPWM) control method. Combining with the fuzzy PID control principle, fuzzy PID control strategy of permanent magnet synchronous motor is studied. This paper discusses the method of establishing SVPWM control system...
Supercapacitor is a new type of energy storage element, and its performance is easily influenced by temperature. In order to have more precise energy storage characteristic research of supercapacitor, a modified porous circuit equivalent model is proposed on the basis of porous circuit equivalent model in electric double layer supercapacitor. The simulation results show that modified porous circuit...
In the process of location and rectification of signal source with exceeding radiation in electronic module or device, there constantly are signals mixing together in frequency domain, which could not be separated with the method of single-channel blind source separation (SC-BSS) effectively. For this issues that SC-BSS have no use in solving mixed signals, this paper proposes to separate mixed signals...
In most of the existing compressed sensing based Massive MIMO channel state information acquisition schemes, the huge overhead introduced by reconstruction and measurement of channel cannot afford by power-limited users. Combining channel estimation and feedback together, a Two-dimensional compressed sensing schemes is proposed for Massive MIMO channel state information. Instead of reconstruct the...
By exploiting the correlations of the massive MIMO channel, Compressed Sensing (CS) has been applied to develop efficient channel feedback scheme. The existing CS-based channel feedback schemes, however, adopt Gaussian random matrices to compress the channel, which will impose an unreachable memory and computation requirement on user equipment (UE). In this paper, a new Toeplitz-structured measurement...
In the study, a subject matter is to be ways of evacuating the wounded from a battlefield. The goal of the paper is to find the fastest and the most economical way of evacuating the wounded and create the simulation model of the MEDEVAC operations. In the process, the existing MEDEVAC actions have been investigated, the analysis of the technical vehicles used at evacuation has been carried out. As...
Sparse representation based classification has recently been shown to provide excellent results in many object recognition and classification tasks. The high cost of computing, however, is a major obstacle that limits the applicability of these methods in battlefield information process scenarios where process time and computational power is restricted. In this paper, we study a fast and computationally...
In order to make further efforts to reduce the cost of switched reluctance drive which is designed for electric bicycle, a sampling scheme for single current sensor is proposed. Under the single current sensor sampling scheme, principle of unobservable area within the current ripple are analyzed. By establishing equivalent circuit model, the relationship between the maximum value of pulse current,...
The high dimensionality of the current battlefield information increases the complexity of the information utilization, which leads to the deterioration of the battlefield information services. The effective reduction of the of battlefield information dimension by information feature selection is an important prerequisite for the effective development of battlefield information service. The traditional...
The decoupling current controller with high dynamic performance is required in the high speed regulation of a vector controlled PMSM system. In this paper, the “relative gain” is introduced to analyze the coupling phenomena of PMSM current loop firstly. Then, three different decoupling schemes based on internal model control, feed-forward compensation and diagonal compensation are elaborated. By adopting...
A wireless power transfer system using multilayer flat spiral coils is constructed in this paper. The multilayer flat spiral coil can deliver power highly efficiently, being used in the resonator coupling WPT system. Thus, three structures of inductive coil are displayed in order to compare the benefits of the multilayer flat spiral coil. The second part describes three structures of the coils and...
It is significant to obtain the impacts of meteorology on power grid effectively in power grid operation and planning. This paper attempts to offer a approach to analyzing the effect of meteorological environment on the power grid, not only meteorological hazard but also conventional meteorological environment such as air pollution and temperature. In this article the business requirements about the...
In this paper a hybrid power flow algorithm is proposed for multi-terminal AC-DC distribution system. Droop control is regularly used for multi-terminal system to coordinate the power output of each source, causing that the voltage of the slack bus is also needed to be calculated for power flow with an iteration-based method. So In this paper Newton method is adopted for DC distribution system, and...
Electromagnetic acoustic transducer (EMAT) is used for rail base flaw detection. The bidirectional radiation pattern of Shear Vertical wave (SV-wave) EMAT limits the accuracy and efficiency of the transducers. In view of this problem, a method of generating unidirectional focusing SV wave is brought up by a unidirectional line-focusing SV-wave EMAT. A 2D finite element model is built to demonstrate...
The accurate measurements for fiber propagation delay is the prerequisite of timing accuracy in high precision optical fiber timing system. A certain of processing is needed for measurements because the original measurements generally cannot meet the accuracy requirement. The commonly used methods such as Adjacent-averaging method and modeling method based on the measurement have low efficiency or...
The Phasor Measurement Unit(PMU) is used for accurate measurement of synchronous phasor of voltages and currents at separated points across the power grid and are widely installed at the transmission level. As the next point of setup in smart grid, PMU is necessary for components control, fault detection and control, energy management in distribution network. This paper first illustrates the architecture...
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