Volume 40,Issue 8,2017 Table of Contents

1 Application of quantum genetic algorithm to the optimum design of permanent magnet synchronous in-wheel motor

ZHANG Yu , DENG Zhaoxiang , ZHANG Heshan , TAO Shengchao , TANG Bei

2017, 40(8):1-8. DOI: 10.11835/j.issn.1000-582X.2017.08.001

[Abstract](1065) [HTML](300) [PDF 2.98 M](1354)

Abstract:
Quantum genetic algorithm (QGA) has advantages of small population size with good algorithm performance, fast convergent rate and powerful ability of global search. In order to acquire high power density and low cost in-wheel motor of electric vehicle,based on the quantum genetic algorithm, a designed outer-rotor permanent magnet synchronous in-wheel motor model with 8 designed variables and 5 constraints was built to optimize the effective quality, material cost and power consumption. The results show that the effective quality, material cost and power consumption of the motor are decreased and the efficiency of the motor is improved. The results of finite element analysis are close to those calculated by quantum genetic algorithm,which can satisfy the using requirements of driving in-wheel motor electric vehicle. Therefore, the QGA is an effective and feasible algorithm in optimization design of in-wheel motor.

2 Reliability modeling and fault diagnosing method of complex electromechanical products based on meta-action decomposition

ZHANG Genbao , WANG Xin , RAN Yan , ZHU Guoyun

2017, 40(8):9-18. DOI: 10.11835/j.issn.1000-582X.2017.08.002

[Abstract](895) [HTML](344) [PDF 4.57 M](1133)

Abstract:
To study the fault diagnosis method of many-movement complex electromechanical products, we first decomposed complex electromechanical products according to functions-movement-action(FMA) structural decomposition and established a reliability and fault diagnosis model based on meta-action decomposition and signed directed graph. Then, to improve the ability of fault identification, we brought the meta-action quantitative information of complex electromechanical products into the reliability and fault diagnosis model and diagnosed the fault of meta-action quantitatively by fuzzy theory. The proposed method can improve the fault identification ability of products by monitoring the operating status variables, and provide a fundamental model for fault root cause analysis. Finally, certain machining center was taken as an example to verify the effectiveness of proposed model and analysis method.

3 VDO knock diagnosis expansion algorithm based on moving window domain

ZHANG Li , ZHENG Renwei , ZHANG Qing , WU Liancheng

2017, 40(8):19-26. DOI: 10.11835/j.issn.1000-582X.2017.08.003

[Abstract](1277) [HTML](608) [PDF 6.69 M](1083)

Abstract:
Siemens VDO knock detection algorithm is widely used in knock diagnosis in gasoline engine. However, the evaluating accuracy of knock is partly affected by the thought that the knock window is determined on the falling edge of cylinder pressure when knock occurs earlier than the peak pressure. VDO knock diagnosis expansion algorithm based on MWD (moving window domain) was proposed and the identification parameter △E_max was introduced to characterize the maximal accumulative high-frequency energy difference between a knock window and a reference window. By moving the reference window and the knock window within the area K, the knock calculation starting point can be detected accurately and more knock energy can be contained in the knock window. The ratio of the integral energy in the knock window and the reference window at this condition was defined as the knock factor. The result shows that the knock calculation starting point of MWD algorithm is earlier than the one of VDO method. It can present more knock energy information and avoid the missed diagnosis of the knock occurring earlier than the peak pressure.

4 A review of interpolation algorithms in discrete spectrum correction and a comparative study of their accuracy under strong noise

XIAO Hong , YANG Yong , XIE Ming , LUO Jiufei

2017, 40(8):27-36. DOI: 10.11835/j.issn.1000-582X.2017.08.004

[Abstract](1050) [HTML](1204) [PDF 1.92 M](1786)

Abstract:
Interpolation DFT (discrete Fourier transform) is the most widely applied and deeply studied approach in spectrum correction methods. A lot of interpolation algorithms were proposed in past decades, which can be divided into amplitude-spectrum-based algorithms and complex-spectrum-based algorithms. Anti-noise performance is one of the most important indexes for evaluating an algorithm in the practical engineering applications. On the review of the theory and the development in recent years of interpolation methods, the principles and characteristics of different algorithms were briefly introduced. In addition, the anti-noise performance of algorithms was investigated through computer simulations. The problem of incorrect polarity estimation was particularly analyzed. At last, the deficiency and problems in the current interpolation approaches were pointed out, and the future developments and prospects of interpolation algorithms were discussed.

5 Wind turbine modeling and dynamic characteristics simulation analysis under complicate sea conditions

JIA Wenqiang , JIN Xin , LI Lang , TANG Shuai

2017, 40(8):37-44. DOI: 10.11835/j.issn.1000-582X.2017.08.005

[Abstract](1040) [HTML](586) [PDF 3.58 M](1351)

Abstract:
Considering offshore wind turbines may be affected by ice load, random ice force model was added to wind turbine model and wave action was simulated by using Morison equation. In order to assess the risk of wind turbine system operation, multi-body dynamics model was established with sea ice action to conduct dynamic characteristics analysis of wind turbine under multi-field coupling. The results show that tower displacement fluctuations are mainly affected by wind load. Wave or ice can directly impact tower foundation load performance, making tower continuously vibrate and causing fatigue damage. When wind and ice come together, tower vibration becomes more intense. Since sea ice's continuous strike makes tower foundation load generally greater than that without sea ice case, the design of wind turbine for ice conditions should be corrected and improved.

6 Analysis on stress and influence factors of buried pipelines under uneven settlement

MA Xiaoming , KANG Xun

2017, 40(8):45-52. DOI: 10.11835/j.issn.1000-582X.2017.08.006

[Abstract](1081) [HTML](402) [PDF 2.54 M](2011)

Abstract:
It is necessary to study the stress and its influence factors of buried pipelines which are under uneven settlement in order to ensure the safe operation. Stress measurement was taken on 3 representative testing points on pipelines and the pipelines' stress in operation was obtained. The nonlinear contact model of pipe and soil was built by using ANSYS. By analyzing the model, pipelines stress was obtained and the mapping relationship of the settlement with the maximum Von-Mises stress was set up. Based on this model, the influence of diameter, wall thickness, burial depth, soil's elasticity modulus and Poisson's ratio on the stress status of pipelines were also studied. Increasing wall thickness and soil's elasticity modulus and decreasing burial depth and diameter can reduce the maximum Von-Mises stress of pipelines under uneven settlement. The research methods and achievements may offer basis and measures for further researches on mechanical characteristics of natural gas pipelines under uneven settlement.

7 An extended duty ratio DC/DC converter with three-winding coupled inductor

WU Guiyang , ZHANG Jiayan , CHEN Hao , HU Xuefeng

2017, 40(8):53-62. DOI: 10.11835/j.issn.1000-582X.2017.08.007

[Abstract](1020) [HTML](467) [PDF 5.59 M](914)

Abstract:
In this paper, an interleaved high step-up DC-DC converter with winding-cross-coupled inductors is presented. Firstly, the second winding of each coupled inductor is connected with a capacitor, which composes a quasi voltage multiplier unit (QVMU). Then, a boost circuit consists of the QVMU, the primary winding and the main switch. Moreover, the QVMU can be charged through the clamp capacitor and the third winding of the other phase coupled inductor. Thus, two phases can be cross-coupled. Furthermore, the primary currents of two coupled inductors are interleaved in parallel at input. There are many advantages of the above-mentioned structure. Firstly, the proposed converter can be operated in the duty cycle of the entire range of variation and the expression of the voltage gain can be consistent across the range of the duty cycle. Secondly, the output voltage and input current of each phase can be automatically regulated to be equally distributed. Thirdly, the proposed converter can achieve a high step-up voltage conversion and the voltage stress on the power devices can be reduced. Lastly, a high step-up gain can be flexibly adjusted. The operating principle of the proposed converter is analyzed. In order to verify the theoretical analysis, an experimental prototype is built.

8 Simulation system of field voltage sensor based on the D-dot sensor

ZHANG Yu , WANG Jingang , WANG Yonghua , LIN Sen

2017, 40(8):63-69. DOI: 10.11835/j.issn.1000-582X.2017.08.008

[Abstract](1531) [HTML](405) [PDF 2.70 M](1196)

Abstract:
The conventional voltage sensor measures voltage through the energy transfer by the core. While, due to the saturation magnetization of the core, the band response of measurement becomes narrow, and ferromagnetic resonance over-voltage appears. We presented a D-dot sensor for voltage measurement, introduced its working principle and designed a new type of voltage sensor test system to test its precision and accuracy. The D-dot sensor is connected with the collection terminal on the ground through the wireless network of hardware system, composing of ground simulation test system. The capture terminal can receive, process and analysis signals with LabVIEW technology. A test platform was built to simulate the voltage transformers in wire line of 10 kV voltage. The results show that the D-dot sensor has high precision and fast response, and the simulation system is stable and reliable.

9 A calculation model for determining number of hot metal ladle based on queuing theory with constraints of system capacity

GU Zongxi , XU Anjun , HE Dongfeng , FENG Kai

2017, 40(8):70-77. DOI: 10.11835/j.issn.1000-582X.2017.08.009

[Abstract](1262) [HTML](467) [PDF 1.49 M](1537)

Abstract:
The process of ladle turnover in "one ladle to an end" mode was abstracted as three serial and nearly closed queuing systems with system capacity constraints, i.e. BF iron tapping, desulfurization and BOF iron charging queuing system. A calculation model of theoretical turnaround number of hot metal ladle based on the queuing theory with limited system capacity was proposed. Theoretical turnaround number of Chongqing Iron and Steel Co., Ltd. was calculated by adopting proposed model, and the results are:294 min for turnaround time of ladle reaching statistical balance; 17 theoretical turnaround number of ladle. Research shows that optimizing the system capacity should be a crucial step to reduce the turnaround number of ladle. The main measures of practical production lie in improving the distribution strategy of empty ladle and strengthening the coordination between iron-making and steelmaking process, et al. Corresponding parameters are obtained by adopting the calculation model, i.e. 260min for l turnaround time of ladle; 15 theoretical turnaround number of ladle.

10 The active trailer steering strategy for articulated heavy vehicles based on modes switching in medium/high speed conditions

NIE Zhigen , ZONG Changfu , YANG Xiujian , GAO Jin , ZHANG Kun

2017, 40(8):78-89. DOI: 10.11835/j.issn.1000-582X.2017.08.010

[Abstract](1045) [HTML](304) [PDF 3.95 M](1310)

Abstract:
In order to achieve optimal control of articulated heavy vehicles under medium/high speed uncertain conditions, an active trailer steering strategy for articulated heavy vehicles based on mode switching in medium/high speed conditions is presented based on the linear variable real-time parameters simplified model. The active trailer steering strategy is based on trailer active steering. According to different medium/high speed conditions, the different control modes are used to control in the strategy. The aims, which are to control vehicle rollover under the limit condition and to achieve the good path follow,yaw and jackknife stability under the normal working condition, are obtained. In order to obtain the optimal control effect for the different control objectives, the optimal weight coefficients,which are suitable for different control modes, are obtained by the genetic particle swarm optimization algorithm. Simulation study is operated and simulation results indicate that:from low adhesion to high adhesion, from normal working condition to limit working condition, the proposed strategy can achieve good control in medium/high speed conditions.

11 Mechanism of the oxidation process of the aliphatic sulfoether structure in coal

DENG Cunbao , DAI Fengwei , DENG Hanzhong , WANG Yubo

2017, 40(8):90-98. DOI: 10.11835/j.issn.1000-582X.2017.08.011

[Abstract](1089) [HTML](404) [PDF 4.22 M](1283)

Abstract:
The energy change generated from aliphatic sulfoether structure (C₆H₅CH₂SCH₃) in coal adsorbing O₂ and oxidation was studied by using Gaussian 03 program and density functional theory (DFT) method at the B3LYP/6-31G (d, p) level, and the oxidation mechanism was analyzed to provide theoretical basis for preventing coal spontaneous combustion. The results show that the energy of complex Ⅰ formed from C₆H₅CH₂SCH₃ structure in coal adsorbing O₂ is the local least, and the formation is a stable no barrier process in thermodynamics. The interaction distance d_S-O between C₆H₅CH₂SCH₃ structure in coal and O₂ is 2.582 Å, and the interaction energy is -20.60 kJ/mol after CP correction. Analyzing the electron density change of complex Ⅰ shows the interaction is Van der Waals forces, which belongs to physical adsorption. The complex Ⅰ will react when it absorbs enough energy. There are five reaction paths in oxidation reaction of C₆H₅CH₂SCH₃ structures in coal, Path 4 is the main reaction path, and P₃ (C₆H₅CH₂SOH+CH₂O) is its principal product. The analysis shows that C₆H₅CH₂SCH₃ structure in coal is easy to be preliminarily oxidized, only 12.36 kJ/mol energy is needed and the energy of physically absorbing an O₂ molecule is enough. But deep oxidation along with Path 4 needs as much as the energy of physically adsorbing 5 O₂ molecules.

12 Mortar anchor solid's corrosion morphology characteristics and fractal dimension

WANG Guilin , LI Tianqi , JI Xi

2017, 40(8):99-108. DOI: 10.11835/j.issn.1000-582X.2017.08.012

[Abstract](825) [HTML](565) [PDF 4.68 M](931)

Abstract:
Based on the scanning electron microscope(SEM) images taken from the mortar anchor corrosion experiment, we extracted the mortar anchors' microscopic morphology characteristics by image processing technology first, and quantitatively described the morphology characteristics by fractal theory. Then the relationship between the fractal dimension and the macroscopic bond strength of mortar anchor was established. Finally, the mercury intrusion test was applied to analyze the results of SEM image processing. The results show that, as the corrosion time gets longer, the anchor's porosities under both force conditions and non-force conditions linearly increase, but the pore number and the pore fractal dimension gradually reduce, and the relationship between fractal dimension and porosity is almost negatively linear. As the fractal dimension decreases, the bond strength of mortar anchor increases first, and then decreases. The results comparison of mercury intrusion test and the image processing shows that the inaccuracy is within the range of 5% to 7%.

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