Search

Abstract: In this paper, direct torque control (DTC) algorithms for double star permanent magnet synchronous machine alimented by two inverters is described. The double star permanent magnet synchronous machine has two sets of three-phase stator windings spatially shifted up by an angle γ=300. The double star permanent magnet synchronous is used in areas of high power industrial applications such as traction and naval propulsion. Because constitute an advantageous choice compared to classical synchronous machine, because of the relatively low torque produced. This machine is controlled by tree level direct torque with speed regulator PI, replaced by the sliding mode regulator to improve the results obtained. The implementation of the DTC multi-level applied to a double star permanent magnet synchronous machine is validated with simulated results. In this paper a method for modeling and simulation of double star permanent magnet synchronous motor drive MATLAB/Simulink. [Copyright &y& Elsevier]

Abstract: This paper described the structure of a Shunt Active Power Filter system and compared various methods of active power filter harmonic detection, then the improved adaptive algorithm was used in active power filter harmonic detection; as regards the control strategy, the control method that based on optimal voltage space vector hysteresis current was presented in this paper for tracking control, And by using Matlab/Simulink simulation software, the Adaptive filter detection system and control model of Three-phase three-wire Shunt Active Power Filter were established. Simulation results showed that the selected detection method and control strategy of harmonic current played a fairly good compensation role on the harmonics which was generated by nonlinear loads and had a good dynamic compensation performance. [Copyright &y& Elsevier]

Abstract: A large AC generator is an important component of the power system. Researches on the AC generator relaying for the next-generation ECMS and an efficient operation of protection control system are necessary. These require developments on detailed generator modeling and internal fault analysis, and prototyping for multifunctional IED device dedicated to next-generation production. In this paper, over-excitation relaying algorithm is one of the main protection elements which have an important role in DGPS(Digital Generator Protection System), was proposed. This paper first briefly introduces a principles of over-excitation and DFT-based gain compensation algorithm was adopted for the frequency measurement. Subsequently, protection scheme of over-excitation was presented. The 765[kV] modeling data of South Korea using EMTP-RV was used for simulations. The simulation result of over-excitation relaying are also provided. [Copyright &y& Elsevier]

Abstract: This paper mainly focused on the surface-surface intersection problem in surface border modeling. This paper introduced the intersection testing algorithm to obtain the initial intersecting lines based on the Delaunay triangulation of two surfaces. After the detection of intersecting lines’ continuity, the “weighted surface border extension algorithm” was put forward to guarantee the continuity of intersecting lines. When the discrete data is deficiency, “weighted surface border extension algorithm” is applied to guarantee the existence of intersecting lines between the surfaces which have the tendency to intersect. This paper applied “weighted surface border extension algorithm” on the result of intersecting lines to guarantee that the endpoints of intersecting lines lie on the border of both surfaces, which can be convenient to the following Constrained Delaunay Triangulation and surface cutting steps. Simulation results showed the proposed algorithm was feasible. [Copyright &y& Elsevier]

Abstract: The paper adopts the method of modularized modeling, creating an electro-mechanic simulation model for a Microturbine Generation System (MTGS), including the micro-turbine engine, permanent magnetic synchronous generator, rectifier and inverter. In this paper, control strategy for grid-connected and islanding operations of a micro-turbine generation system is researched, the former adopts output voltage control strategy to maintain the output voltage of the load, and the latter adopts a dual closed-loop control algorithm based on PQ decoupling. A new control strategy to regulate the output power of MTGS based on the combination of decoupled control of output voltage and hysteresis current control is also introduced. Simulations have been done, and result proves the feasibility of the strategy. [Copyright &y& Elsevier]

Abstract: This paper presents a fast optimal generator shedding algorithm which is on the basis of predictor-corrector method and time domain simulation for transient stability. It includes two parts that are the fast time domain simulation and optimal generator shedding. On the basis of the generator''s classical model and load''s constant impedance model, this paper use fourth-order Hamming predictor-correction formula to compute differential equations of the system with large step length, in order to improve computing speed. The second part shows how to calculate the sensitivity of transient stability constraint function to control variables, by the application of optimal control theory. Combined with the discrete characteristics of generator shedding, “Micro-step discrete method” is proposed, which is fast, accurate and so on. The advantages of this method are verified by analysis results of New England 39-bus test system. [Copyright &y& Elsevier]

Abstract: This paper discusses the modeling and control of Voltage Source Converter High Voltage Direct Current (VSC HVDC) systems in a multi-terminal configuration (MTDC). Both steady-state interactions, as well as transient stability modeling and control are addressed. Simulation results show that adequately modelling the DC voltage droop characteristics or a distributed voltage control in both the power flow algorithm and in the transient stability models allows to simulate the steady-state results of the dynamic simulation by means of power flow software algorithms. [Copyright &y& Elsevier]

Abstract: Frequency is an important parameter of a power system, and frequency measurement is a very important link in a power system measurement device. This paper compared the accuracy of the Fourier frequency measurement algorithm with different sampling period, chose the method of whole cycle to improve. Calculated based on the empirical model and used the least error squares fitting the error compensation curve to correct the result and get a new algorithm in frequency measurement which is convenient in calculation, high precision and real-time because it need only 2 sampling cycle and does not increase the complexity. The simulation results show the frequency value measured by improved algorithm is highly accurate and can be applied in a quick arc-suppressing system. [Copyright &y& Elsevier]

Abstract: The Purposes of this paper describes Gezhouba to Nanqiao rectifier direct current transmission project PI controller, through the intelligent control theory and the combination of the traditional PI controller are intelligent controller—HVDC fuzzy-PI controller, using the improved genetic algorithm domain Fuzzy- PI controller''s language of control theory. The result of improved intelligent controller has a simple structure, fast response characteristics. Using MATLAB / SIULIKMN the fuzzy toolbox and genetic algorithm toolbox for system simulation, simulation results show that the Conclusions of the intelligent controller has better adaptability and dynamic features to improve the robustness of the system and transient stability for the intelligent control of high voltage DC reference [Copyright &y& Elsevier]

Abstract: This paper presents a new control strategy combining the direct torque control of induction motors with the dual bridge matrix converter, and gives the modulation algorithms of dual bridge matrix converter rectifier and the method of inverter direct torque control. This control method can realize the direct torque control of induction motors with a good dynamic performance, but also get good input current waveforms and adjustable power factor. The simulation results show the validity and feasibility of the proposed control strategy. [Copyright &y& Elsevier]

Abstract: In this paper, a traction control algorithm based on fuzzy PID is proposed, and a hardware Hardware-in-the-loop (HIL) test bench which is based on the xPC Target™ product of MATLAB® is introduced. The control algorithm is validated using the test bench and the test results of show that the algorithm can control the spin of driven wheels effectively. [Copyright &y& Elsevier]

Abstract: Nowadays, renewable energies have taken a special role in power systems and most of distributed generations (DGs) in power systems also utilize these types of energy resources. Their advantage, including the use of renewable energies which are not polluting environment and owning endless nature, the use of these resources to produce electrical energy in the world is increasing. A problem with such generators is the unwanted islanding phenomenon. In this paper, a new technique to detect islanding conditions has been proposed. The performance of the proposed method based on passive methods is much more appropriate than that of previous methods. The simulation results performed in MATLAB, clearly show improved operation of this method. [Copyright &y& Elsevier]

Abstract: A Mobile Ad Hoc Network (MANET) is a dynamic wireless network that can be formed without the need for any pre-existing infrastructure in which each node can act as a router. Clustering is a method for hierarchical management of a network. Especially, clustering is often used in MANETs. In order to maintain the stability of clusters, speed of mobile nodes, but not the identity and connectivity, are taken as the basis of clusterhead election. This paper proposes Mobility Entropy-based Clusterhead selection Algorithm for ad hoc networks (MECA). The protocol constructs a new etric of node stability and selects a stable clusterhead with the help of entropy metric to reduce the number of clusterhead reconstruction. It selects the nodes which have the most weight and stability to be the clusterheaders. Simulations demonstrate the performance benefits of our proposal MECA over RSCA in most movement scenarios. [Copyright &y& Elsevier]

Abstract: A computation model of fractional-order differentiators based on functional network and the learning Algorithm of functional network using particle swarm optimization was proposed. it provided a new method to compete the numerical calculation of fractional-order differentiators in other fields. the simulation results demonstrate that the method presented in the paper is more efficient and feasible. [Copyright &y& Elsevier]

Abstract: To solve the increasing problem of Inter-cell interference in LTE, put forward an algorithm based on technologies of SRS sounding and Adaptive Modulation and Coding which is proved, in this paper, to be adequately achieve the goal of Inter-cell interference coordination/avoidance. Simulation and analyzing of the algorithm have indicated that it could effectively improve the performance of the subscribers located at the edge of the cells in a certain degree. [Copyright &y& Elsevier]

Abstract: A detail which has been omitted when modeling non-linear power amplifiers (PAs) is the time delay that exists between the input and output baseband data waveforms of the PA. The time delay should be estimated and compensated because any time delay could induce an extra dispersion of AM/AM and AM/PM characteristics of the PAs. The interpolation has been utilized for the estimation of time delay of PAs . Four kind of interpolation algorithm are used for the estimation in this paper. The simulation results show that the Sinc interpolation algorithm is more appropriate than the others for the estimation of time delay of PAs. [Copyright &y& Elsevier]

Abstract: A background modeling scheme in compressed sensing (CS) imaging system is proposed in this paper, in which background evaluation is performed on the measurement vectors directly before reconstruction. The estimated background measurement vector is constructed through average, running average, median and block-based selective method respectively. Then the estimated background image is reconstructed using the background model measurements through the gradient projection for sparse reconstruction (GPSR) algorithm. The simulations show that the proposed background modeling algorithms in CS scheme provide promising results. [Copyright &y& Elsevier]

Abstract: Analysis of power cost data belongs to small sample problem, because it is difficult to collect such type data. Many data mining algorithm and theory such as neural network cannot acquire good analysis effect. In this paper, based on SVM, modified algorithm and its model of SVM is introduced, moreover, such algorithm and its model is used to data mining and knowledge discovery of power cost data. Simulation results in MATLAB show that such algorithm and its model have high prediction exactness in power data analysis and can supply scientific and reasonable reference to control power cost. [Copyright &y& Elsevier]

Abstract: In ISAR imaging of the target with rotating parts, the motion compensation algorithm is usually invalid because the disturbance of rotating parts. To solve this problem, this paper proposes a novel algorithm based on dividing the data into several pieces. The range profile is divided into several parts, then the interesting part is selected by the minimum entropy criterion, finally the influence of rotating parts is restrained effectively, and well-focused imaging can be obtained. This is very important for the separating rotating parts from the rigid body. Imaging results of both simulated and real data are given to verify the validity of the proposed algorithm. [Copyright &y& Elsevier]

Abstract: The specific problem addressed in this paper is interpolating N × M video frames to a frame size of 2N × 2M. We introduce a recursive interpolation method called Adaptive Prediction Tree (APT) to implement the issue. APT is an empirically optimized nonlinear predictor, and it recursively use a square grid of pixels to predict another square grid of samples located at the midpoints of the squares of the first grid. The same method of interpolating new pixels is followed at successive levels of resolution, until the full pixel grid is reached. Simulation results demonstrate that our new interpolation algorithm improves both subjective quality and PSNR compared to conventional linear interpolation method. [Copyright &y& Elsevier]

Abstract: A new classification algorithm of M-ary FSK signals based on the extraction of signals’ features is presented in this paper. The implementation of the methodology does not require any apriori information. By extracting some basic features of intermediate frequency signals both in time domain and frequency domain, the classification of M-ary FSK signals is achieved. Simulation result shows that the proposed algorithm can classify 2FSK, 4FSK and 8FSK signals effectively under AWGN and and still keeps a good performance even at low input SNR. [Copyright &y& Elsevier]

Abstract: A distribution network reconfiguration method based on simulated annealing immune (SAI) algorithm is proposed in this paper. According to the characteristics of reconfiguration, loop encoding is used and the public switches between loops are disposed in advance, so the individuals in evolution turn to be feasible. Besides, the historic and present optimal individuals are combined to construct vaccine dynamically, and not only the speed of evolution searching but also the individual performance can be improved by inoculation. On the other hand, the selection operator based on Boltzmann annealing method, high frequency mutation and immune supplement are used to keep the population diversity. Through the improvements, the early maturity is avoided effectively. Reconfiguration results show the prompt convergence and effectiveness of proposed method. [Copyright &y& Elsevier]

Abstract: In this paper, considering the problem of low computing and low precision for the least square (LS) algorithm pilot- based in OFDM system, a novel channel estimation algorithm based on discrete Fourier transform (DFT) by transform domain, the proposed method will force time domain response value to zero beyond the length of cycle, the precision of estimation is improved, and setting threshold for time domain response within the length of the cycle to further reduce the noise on the impact of channel estimation. The proposed algorithm retains the advantages of LS algorithm, improve the accuracy of channel estimation, and simulation results show the effectiveness of algorithm. [Copyright &y& Elsevier]

Abstract: In this paper, we analyzed the multi-instance multi-label (MIML) learning structure which proposed by Zhou. In realworld, there are many problems mentioned in complicated systems, traditional MIML structure would only consider the initial and final state, when facing with more tanglesome system, the lack of middle decision layer will affect the whole capability of system. The new proposed structure – layered MIML frame will help us to solve these tasks more easily by middle layer with reward mechanism. Finally, we use RoboCup Simulation 2D as platform to verify our frame and algorithms, the result shows the frame presented is valid and well-performed. [Copyright &y& Elsevier]

Abstract: Orthogonal frequency division multiplexing (OFDM) suffers from a high peak-to-average power ratio (PAPR).Tone reservation is a popular PAPR reduction technique that uses a set of reserved tones to design a peak-canceling signal. In this paper, the performance and complexity of clipping noise guided, complex base-band active-set methods based on tone reservation for PAPR reduction are analyzed and simulated. The simulation results show that the two clipping noise guided methods, the adaptive scale method and constant scale method, have better performance than complex base-band active-set methods. Furthermore, the complexity of the constant scale algorithm is lower than the adaptive scale and the complex base-band active-set algorithm. [Copyright &y& Elsevier]

Abstract: In order to apply cockroach swarm optimization (CSO) algorithm to more function optimization and improve its accuracy, this paper improve CSO by modifying chase-swarming behavior of cockroach, and apply the modified CSO to optimize several Benchmark Problems. The results of simulation experiments illustrate that modified CSO has stronger convergence performance and highly-accuracy optimization results compared with Particle Swarm Optimization (PSO) and Chaotic Particle Swarm Optimization (CPSO). [Copyright &y& Elsevier]