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July 30,2010
Volume 3,Issue 14
Pages 1418-1521
Subject Area:Electric Power System and Automation,Circuit Theory, Electromagnetic Field Theory,Electrical Appliances,Flowing Mechanical Engineering and Hydrodynamic Engineering,Engineering Thermophysics

Title: Research on design method of grid fault diagnosis system

Authors: LIU Tongliang, LIU Daobing, GU Xueping
PP: 1516～1521
Abstract: This paper discussed a method of designing a fault diagnosis and restoration system of electric power systems with the .NET based three tier architecture. The basic principle and characteristic of the .NET based three tier architecture technique were discussed, and the correlation of the three tiers was analyzed according to the development of a practical system. The developed system is of high convenience, security and reliability, and also has a good performance.
Keywords: electrical engineering; .NET; three tier architecture; regional grid; fault diagnosis; fault restoration

Title: Simulation of the permanent magnet synchronous motor based on fading Kalman filter

Authors: YU Yue, HE Fengyou, BAO Weining
PP: 1511～1515
Abstract: The adaptive Kalman filter with fading factor is used to construct the permanent magnet synchronous motor (PMSM) speed observer in this paper. According to the output of the PMSM, the filter can on line adaptively adjust the fading factor, so that the filter still maintains the best convergence, and with a high convergence rate, on the condition that the model error or the interference by outside circumstances is existed. Finally, the test of the PMSM based on fading Kalman filter for Matlab simulation is established. The simulation results confirm that the proposed observer can estimate the motor speed effectively and can achieve a perfect dynamic and statistic performance.
Keywords: electrical engineering; permanent magnet synchronous motor; Kalman filter; adaptive filter; fading factor

Title: High power pulse unbalanced magnetron sputtering induced by direct current

Authors: MU Zongxin, JIA Li, MU Xiaodong, DONG Chuang
PP: 1506～1510
Abstract: This paper reports the phenomenon and mechanism of the direct current induced high power pulse unbalanced magnetron sputtering. The high power pulse discharge of large amplitude and low frequency was formed via controlling the discharge parameters such as the pressure, power and coil current and so on. The study of the relation between the high power pulse discharge properties and the discharge parameters was carried out. The analysis on the characteristics, mechanism and influential factors of pulse waveform was carried out, and based on the qualitative theory of magnetically insulated diode, the values including pulsed ion current and electron current and the like were calculated, which were conform to the test results.
Keywords: electrical engineering；discharge; magnetron; pulse technology

Title: Nonlinear analog fault diagnosis method based on transformation in multidimensional spaces and neural network

Authors: ZHU Wenji， HE Yigang
PP: 1492～1505
Abstract: Based on a bilinear transformation in multidimensional spaces, a neural network based nonlinear analog fault diagnostic system for actual circuits is proposed. This approach allows diagnosing single, double, and multi faults in linear circuits. For nonlinear circuit, after the nonlinear component substituting by their piece wise linear （PWL） models, the method can be used in nonlinear circuit fault diagnosis. Under considering the characteristics of the transformation in multidimensional space, the particle swarm optimization （PSO） algorithm based BP neural network is applied to diagnose faults. Finally, the realization of the proposed strategy is expounded by using two examples.
Keywords: analog circuits; neural network; fault diagnosis; particle swarm optimization; bilinear transformation; multidimensional transfo

Title: Research on sensor head structure simulation of magnetism gathering OCT

Authors: WEI Zhaobi, MA Zhiying, DONG Ziliang, TU Yu
PP: 1486～1491
Abstract: Flexible and stable magnetism gathering OCT with high measurement sensitivity has been chosen as the research prototype in this paper. Factors influencing OCT’s performance were simulated and analyzed using ANSYS software, like the iron core shape, geometry dimension and open air gap length etc. All these contributes to excellent theoretical basis for magnetism gathering structure design.
Keywords: electric measurement technology and instrument; magnetism gathering optical coherence tomography; sensor head; ANSYS software; structure simulation

Title: Study on earth faulty line selection using transient zero sequence current in non solidly earthed network

Authors: QI Dunjin, HAN Zhiqiang, WANG Tao
PP: 1479～1485
Abstract: After analyzing a lot of experimental data from the simulation of power network, the features of zero sequence transient currents in faulty feeder arcing fault and healthy feeders while arcing fault occurs was obtained. The steady state and transient process was introduced. Due to the limitation of the simulation of power network, a round of five 10 kV feeder for the simulation of a large number of single phase to ground fault was modeled with Matlab 7 1/Simulink 6 3. A new method of single phase grounded feeder detection in indirectly earthed power system based on the ratio of the first half wave of zero sequence transient current was introduced and a large number of simulation experiments under different conditions to further verify the validity of the method.
Keywords: electric power system and its automation; indirectly earthed power system; single phase earth fault; zero sequence current; transient state component Simulink

Title: Discussion on 20 kV branch single phase to earth protection scheme

Authors: WANG Tong， LIU Haoming
PP: 1474～1478
Abstract: The neutral point usually grounds with low resistance in 20 kV distribution network. The traditional two zones zero sequence over current protection always fails to act in case of single phase high resistance earth fault. A new scheme is proposed in this paper, which can act correctly via directional zero sequence power protection. Simulation and analysis are implemented. The results indicate that the proposed directional zero sequence power protection is reliable and sensitive.
Keywords: electric power system and automation; 20 kV branch; low resistance grounding; high resistance earth fault; directional zero sequence power protection

Title: A new feeder selection algorithm for neutral indirectly grounded system based on Prony and morphological filter

Authors: LIU Qi, REN Jianwen, LI Zhi
PP: 1469～1473
Abstract: Prony algorithm is a method in which a set of linear combination of exponential components are used to fit the uniformly spaced sampling data. With the algorithm, the amplitude, phase, damping and frequency of the signal can be analyzed. It is suitable for the handing of transient information, but is noise sensitive. The combined morphological filter is developed to filter noise in transient zero sequence voltages and currents in order to reduce the impact of noise on the selection, and then the fault line could be detected by comparing the amplitude and phase of that. Theoretical analysis and simulation results show that the proposed method can detect the fault line reliably and exactly.
Keywords: electrical power system and its automation; neutral indirectly grounded system; single line to ground fault; Prony method; morphological filter

Title: An extended cutting plane method for solving unit commitment

Authors: QUAN Ran, JIAN Jinbao
PP: 1464～1468
Abstract: An extended cutting plane method (ECPM) is proposed for solving unit commitment (UC) problems. First, the unit commitment problem is reformulated as a convex mixed integer quadratic programming (MIQP), then, ECPM is used to solve the MIQP. The ECPM is an extended cutting plane method for the solution of convex nonlinear programming, and it can get the global solution of the convex mixed integer nonlinear programming by sequentially solving mixed integer linear programming. The simulation results for systems up to 100 units and 24 hours show that the presented method can yield good sub optimal solution in less computing time and is suitable for solving large scale unit commitment problems. Hence, it is a prospective method in the future.
Keywords: electric power system and automation; unit commitment; mixed integer quadratic programming; extended cutting plane method; mixed integer linear programming

Title: The fault diagnosis of complex grid based on particle swarm optimization

Authors: QIAN Lei, WANG Jinxiu, XU Qingshan
PP: 1457～1463
Abstract: Power consumers are requesting more on reliability while the network fault is inevitable due to the reasons of operation, maintenance, insulation and et al. Fast fault diagnosis and elimination can enhance the speed of examine, repair and restoration, as well as operation stability and reliability, which leads to more national profits. As a burgeoning evolutionary computation technology, swarm intelligence is now becoming a new research hotspot; it is a kind of effective method to solve most global optimal problems.
Keywords: power system; fault diagnosis; particle swarm optimization; inertia weight

Title: Calculation of electromagnetic wave propagation in the plasma media by using time domain integration equation method

Authors: YANG Guangyuan, SHAO Keran
PP: 1451～1456
Abstract: This paper discusses the application of electromagnetic wave propagation in the plasma media using algorithm of time domain integration equation (TDIE). The keystones of boundary element method (BEM) and TDIE are briefly presented. The integration equation of field domain in plasma media is deduced. The marching on in time (MOT) and plane wave time domain (PWTD) when solving the equation are also discussed. Compared to frequency domain algorithms, time domain algorithm has the following advantages: more suitable for broadband signals; more suitable for large scale parallel computing; can be more intuitive in understanding of market interactions; and can easily and directly deal with non linear medium and the scattering of time varying media and radiation.
Keywords: electrical dnd fontrol engineering; plasma; marching on in time method; time domain integration equation method; plane wave time domain method

Title: Spark advance angle calibration for gasoline engine based on uniform design

Authors: ZHOU Naijun, HOU Zhanjie, LUO Guangde, YANG Nan
PP: 1446～1450
Abstract: In order to solve the parameters calibration problem with a large number of parameters, longer development period and increasing experiment cost, basic spark advance angle was calibrated based on uniform design by the open electronic control unit (ECU) with host computer control system developed by the studying team by taking MR479Q gasoline engine as research object. Basic spark advance angle was predicted successfully by applying polynomial regression models. The results show that, the amount of test points reduces from 170 to 30, and the absolute mean error is 0.871 3 CA compared to that obtained by comprehensive test, which is proved to have high engineering value as significantly reduces the calibration development time and costs.
Keywords: internal combustion engine test; calibration; uniform design; spark advance angle; gasoline engine

Title: 3D numerical calculation of the interfere between small disturbance waves in swirling flow and guide vane

Authors: GAN Jiaye, HUANG Xuefen, WU Keqi
PP: 1441～1445
Abstract: By solving the three dimensional linearized Euler equations, this paper researched the interference phenomenon between small disturbance waves and no load annular cascade. The small disturbance waves was contained no viscous, compressible swirling flow in pipes. It uses regular modal analysis method, and the incident wave is decomposed into approximate speed of sound and approximate convective disturbances. And optimized compact scheme was used for spatial derivative discretization. Integral function is solved by the classical fourth order Runge Kutta method. First, it verify the reliability of calculation method through a calculation to a standard problem. Finally, it gives acoustic and aerodynamic results under different conditions. This is used to explore the influence of swirling flow acted on the sound mode in channel and the aerodynamic response of blades.
Keywords: fluid machinery and fluid engineering; rotor/stator interference noise; computational aeroacoustics; canonical modal analysis; non reflecting boundary condition

Title: Experimental study on combustion performance of alcohol based fuel

Authors: LIU Baolin, LI Jian, XU Yuyu, PENG Yan, LI Ran, ZHAO Lingzhi, SHA Ciwen
PP: 1436～1440
Abstract: In this paper, a series of comparison tests between the new alcohol based fuel and conventional liquid fuel (e.g. diesel oil) have been done in the laboratory. The characteristics of flow rate for different burners have been studied while the pressure changing from 7atm to 14atm in the cool test; Stable combustion and emissions of the boiler have been researched and many factors have been discussed in detail in the thermal test. The results provided the reference to clean combustion of the new alcohol based fuel.
Keywords: engineering thermophysics; alcohol based fuels; behavior of combustion; comparison test

Title: Analysis of the influence of experience constants in cavitation models on cavitation flow computations

Authors: HUANG Biao, WANG Guoyu, YUAN Haitao
PP: 1430～1435
Abstract: To investigate the influence of experience constants in cavitation model, the unsteady cavitation flow around the Clark y foil was numerically simulated with different experience constants. It is shown that the diameter of cavitation bubble has a significant impact on the shapes of cavity; the cavity area seems larger when the diameter of cavitation bubble is bigger, and also, the mass fraction of non condensation gas has no significant effect on the frequency distribution of the dynamics.
Keywords: multiphase flow; cavitation model; cavity shape; dynamics characteristic; frequency

Title: The theoretical simulation on critical heat flux of saturated water jet impingement boiling on stagnation zone

Authors: LIU Zhenhua, QIU Yuhao, LI Yuanyang
PP: 1423～1429
Abstract: A theoretical simulation was carried out for predicting the critical heat flux (CHF) of convective boiling for a round saturated water jet impingement on the stagnation zone of a hot surface. The study was focused on the effect of the solid liquid contact angle on the CHF. A theoretical model based on the long wave stability was applied to calculate the maximum liquid sub film thickness under boiling bubbles and finally a semi empirical and semi theoretical correlation was proposed by combining the simulated calculation and the experimental data from the common metal heating surface. The correlation revealed the comprehensive effects of solid liquid contact angles, jet velocity and jet diameter on the CHF and agreed well with the experimental data proposed by authors in the previous study.
Keywords: heat transfer; jet impingement; boiling; critical heat flux; solid liquid contact angle

Title: Research and analysis on thermal computation methods of power plant boilers

Authors: LI Zhenquan, ZHANG Jun
PP: 1418～1422
Abstract: This paper introduces and compares the difference between Soviet Thermal Power Computation Standard and American combustion engineering Boiler Performance Design Standard, points out that it's need to establish the standard of the boiler thermal calculation for China, and suggests the exact comprehensions and importance of ε, ψ and ξ, then also suggests the methods of the thermal calculation and many betterment methods, analyses their virtue and shortage in succession, then expatiates the computer is very important to the thermal calculation, summarizes the computer applications in it. Finally it points out the existing problems and the developmental directions.
Keywords: thermal energy engineering; boiler; reviews; thermal calculation; standard; method

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