SUN Dongye , ZHUANG Jianbing
2009, 32(11):1241-1245.
Abstract:Considering on the characteristics of the transmission system and some key units of continuously variable transmission system with reflux power, a dynamic simulation model and a control strategy are established. The design method of the new continuously variable transmission system is verified by simulation. The simulation result on this continuously variable transmission system shows that the rotating speed of the driven plate can rise up rapidly during starting clutch engagement, and the sliding friction power is lower than 3 kJ which is nearly equal to onethird of the friction power of the traditional vehicle.
CHEN Bingkui , HU Junzhang , LI Chaoyang
2009, 32(11):1246-1251.
Abstract:Based on the principle of doublearc method, continuous twoway circular interpolation method and the control of interpolation error are used to achieve a dynamic expansion on the process step and to get contours node data that meets the requirements of CNC machine tools’ circular interpolation. Accordingly, corresponding CNC program software can be developed. Using this kind of software, the CNC process program can be gotten but only inputting several parameters of the cycloidalpin gear. In this case, automatic programming for cycloid gear of any number of teeth is realized. According to the contours node data and the track coordination of tool center, the process program of cycloid gear can be simulated. The experimental result of cycloidalpin gear CNC grinding validates the correctness of the theory deduction and practicality of the software.
2009, 32(11):1252-1256.
Abstract:In order to satisfy the high reliability requirements of wind turbines gearbox, a method of accelerated fatigue test is proposed to verify the fatigue reliability of the gearbox. According to the design load spectrum, the equivalent load and the number of stress cycles of parts in gearbox are deduced. Based on Miner linear cumulative damage theory, the fatigue degree of the gears and bearings are calculated. A linear accelerated load spectrum with the equivalent fatigue ratio of design load spectrum is provided to check the reliability of the gearbox. The results show that this method can verify the reliability of wind turbine gearbox within about 800 h.
HU Jianjun , LIU Zhenjun , JIANG Wei , YU Mengjin
2009, 32(11):1257-1261.
Abstract:According to kinetic analysis, we put forward a braking control strategy under the down shift condition. When auxiliary engine brake torque affects the stability of vehicle, it should disconnect the clutch; and when auxiliary engine brake torque doesn’t affect the stability of vehicle, it should jointing the clutch. The speed acceleration, the braking time, and the braking distance are analyzed in while the clutch and joint the clutch are disconnect. The analysis indicates that when auxiliary engine brake torque doesn’t affect the stability of vehicle, jointing the clutch can reduce the braking time and distance obviously.
CAO Huajun , DU Yanbin , LIU Fei
2009, 32(11):1262-1267.
Abstract:Based on the practice of machine tool remanufacturing, a software system is developed to support the processes of comprehensive testing and evaluation for machine tool remanufacturing. The software is composed of function models of comprehensive testing and analyzing, redesign and evaluationbased optimization. Based on the test of used machine tools, the redesign scheme of machine tool remanufacturing is presented. In addition, the scheme is evaluated in terms of technology, economy, resource consumption and environmental impact. An example of the used lathe remanufacturing is given to illustrate the application of the system.
DUAN Liming , LI Min , MAO Shihong
2009, 32(11):1268-1273.
Abstract:A digital monitoring and fault diagnosing system for ship power plant based on fuzzy neural network and dempstershafer(DS) evidence theory is developed. The system includes data acquisition part, software control part and analysis part, which can monitor the main propulsion device, diesel generator and auxiliaries. The main propulsion device can be realtime dynamicly monitored by acquiring cylinder pressure and instantaneous angular speed. Using thermodynamic parameters and instantaneous angular speed, two subfuzzy neural networks are parallel constructed. The fault of main propulsion device is judged by data fusing algorithm of DS evidence theory, and finally the result of fault diagnosis can be obtained. Test shows that the system’s realtime performance and measurement accuracy can meet requirements, and the fusion method of fuzzy neural network according to DS evidence theory has relatively high reliability.
HE Wei , HE Chuanhong , LIU Bin
2009, 32(11):1274-1279.
Abstract:Electrical impedance tomography (EIT) system must have the properties of high precision and speed, thus the digital phasesensitive detector (DPSD) based on the field programmable gate array(FPGA) is developed for data collection of EIT. Based on the principle of DPSD, the relationship between signaltonoise ratio (SNR) and sample resolution as well as total number of samples is deduced. An implementation scheme of this system and a method of designing analogtodigital converter (ADC) clock based on direct digital synthesis (DDS) technology are provided. The system adopts highspeed multichannel ADC and low jitter clock conditioner for ADC. Realtime DPSD is implemented with FPGA. The experiments show that the measurement accuracy reaches 0.03% and the SNR reaches 85 dB. The agar phantom experiments prove that the performance of the DPSD meet the designing requirement for EIT.
LIU Yugen , YU Xiaodong , SONG Zinan , SU Yuping , Tian Jinhu
2009, 32(11):1280-1284.
Abstract:The 0.618 method for grounding resistance measurement has long wire lead defect. By calculating and analyzing the groundpotential of a large number of grounding grids which are different in shape, area and rodarrangement style using computer numerical method, it presents that the grounding grids can be equivalent to disc shape grounding electrodes. A new method of grounding resistance measurement is presented that taking the currentelectrode wire as long as the longer side length of grounding grids and voltageelectrode wire as 0.509 times long as the currentelectrode wire. The measurement accuracy of this method is testified by experiment in field. The proposed method has much shorter wire than 0.618 method, it is suited to grounding resistance measurement of large grounding grids.
LI Jingcan , LIAO Yong , YAO Jun
2009, 32(11):1285-1290.
Abstract:Since rotor structures of the IPMSM are different from the common motor, inductance parameters are hard to be accurately calculated by the traditional calculation method. A new analytical method, which is called the fixed permeability method (FPM), is used to calculate the inductance parameters and the magnet flux λm of IPMSM. The results calculated by the FPM and the conventional finite element method (FEM) are compared and the reasons which caused the different results are analyzed. The impacts of saturation and cross coupling on the inductance and the magnet flux λm and the impact of the width of the bridge on the inductance are studied. On the basis of the analysis, the influence factors and the rules of the inductance parameters of IPMSM are summarized, which are good for analysis and design of PMSM.
TANG Zhide , FENG Lixiao , XIE Di , SUN Caixin
2009, 32(11):1291-1295.
Abstract:According to closedloop communication system design of implantable devices and the communication problems, a data communication model based on volume conduction is proposed; volume conduction channel’s basic characteristic is analyzed, namely, when working frequency of volume conduction channel runs in kHz grade, biological background signal interference is insignificant. volume conduction channel can be approximated as additive white gaussian noise channel (AWGN); derived under twodimensional modulation channel capacity formula. Thus, twolevel modulation of channel capacity could be effective at very low signal to noise ratio (SNR), while multilevel modulation should be used at high SNR. Finally, using SystemView of channel simulation, the results show that the twolevel modulation is better than multilevel modulation and verify the effectiveness of the proposed method.
ZHANG Zhanlong , HUANG Danmei , WEI Yu , HE Wei , YANG Fan , WANG Quandi
2009, 32(11):1296-1299.
Abstract:The defective insulator can be detected by measuring electric field, however, the electric field calculation accuracy of the insulator strings is low. Charge simulation method (CSM), which is optimized by genetic algorithm (GA), is adopted to calculate high voltage electrostatic field. The optimal method principle and feasibility analysis is given. The objective function and optimization model of electric field distribution around insulator strings are constructed and analyzed. The results of calculation and analysis demonstrate that adopting the potential of checkpoints near insulator strings as objective function and using GA to optimize the charge of simulation charge, better performance can be achieved for improving ability of global optimization, calculating precision, searching speed, simulating precision of CSM and accuracy of diagnosing defective insulator in the insulator strings.
HUANG Miao , LI Wenyuan , YAN Wei
2009, 32(11):1300-1305.
Abstract:Incorporating the PMU measurements information in transient stability simulation can increase computing speed and enhance accuracy in the timedomain simulation. Based on the conventional alternating iteration technique, this paper presents two simulation methods combined with the PMU measurements information, in which the number of differentialalgebraic equations is reduced and so is the computational scale. The proposed methods have been tested and compared with the conventional method using the New England 10machine 39bus system and IEEE 50machine 145bus system. The cases with errors of the dynamic model parameter and PMU have been also simulated and discussed. The simulation results demonstrate the effectiveness of the presented methods.
YAN Bo , GUO Yueming , CHEN Kequan , LIANG Ming
2009, 32(11):1306-1310.
Abstract:This paper numerically investigates the jump heights of overhead transmission lines after iceshedding by the finite element method, and simulates the dynamic responses of the transmission lines, with different structure parameters, in different iceshedding conditions. Based on the results, it obtains the quantitative relations between the jump height of conductor and the amplitude difference of the two static states of the conductors before and after iceshedding, and proposes a simplified formula for the jump height of conductors in continuous span after iceshedding for the determination of the clearance distance between the conductors at different phases in the design of high voltage transmission lines located in heavy ice zones.
LUO Ciyong , LU Bin , LIU Fei
2009, 32(11):1311-1315.
Abstract:It is sensitive to the initial population while the genetic algorithm (GA) is used to solve the traveling salesman problem (TSP). To overcome this problem, the neighbour field method is presented to create initial population. In this method the next city is not the nearest asyetunvisited location but randomly selected from the unvisited cities in neighbour field. Neighbour filed method can extract the local optimal information of adjacent cities, and the constructed population has the diversity character. Comparing to the random initial method, the mean value obtained by the neighbour field method in four standard test instances of TSPLIB improved by 46.3%. The simulation results show the effectiveness of the neighbour field method for creating the initial population.
WANG Dengke , YIN Guangzhi , ZHANG Dongming
2009, 32(11):1316-1320.
Abstract:Investigation on the creep property of coal containing gas is an effective means for understanding the mechanism of delay outburst of coal and gas in a coal mine. This paper conducts triaxial creep tests on the specimens of gascontaining coal using a selfmade creep experimental apparatus to determine the creep law for coal containing gas. An improved triaxial creep model is developed for containing gas by coupling a Nishihara model with another viscoelastoplastic body which can describe the deformation property of nonNewtonian fluids. The parameter fittings are conducted based on the experimental dada.The present model is examined in terms to the results of triaxial creep tests in various stresslevel cases. The result shows that the proposed model for gascontaining coal can properly represent the creep deformation at different creep stages, especially at the accelerating stage. The instability condition of the model for coal containing gas is also discussed according to stability theories of differential equation solution.
CAO Shugang , LIU Yanbao , LI Yong , ZHANG Liqiang
2009, 32(11):1321-1327.
Abstract:This paper conducts experimental investigation on acoustic emission(AE) characteristics of coal rock at uniaxial and triaxial compression by MTS815 rock mechanics test system. The results show that the variation of AE has tendency effect at uniaxial compression and confining pressure experiments. We indicate that AE signal decreases significantly in the elastic stage, and the relatively quiet period of AE before the specimens failure is not obvious under confining pressure. The AE amplitude distribution with time and its envelope line can indirectly reflect the trend of stress. The AE events peak stress and elastic modulus decrease with the temperature increase, and the value of m which reflects the cumulative distribution of amplitude increases as the confining pressure rises. The results also show that the AE frequency distributes in three frequency domains, and the proportions of dominant frequency significantly increase while the specimens are broken.
WANG Zhisong , SUN Bo , LI Zhengliang , XIAO Zhengzhi
2009, 32(11):1328-1333.
Abstract:Because of the limitation of the model making and the existing wind tunnel’s size, it is difficult to keep the line and tower in the same scaling factor in developing the aeroelastic model of the power transmission lines system, and a distorted scaling factor is needed in span length of the lines. With the instance of a 1 000 kV twocircuit power transmission lines, the finite element analysis under the alongwind load in time history is conducted with keeping the tower in the same and the line scaling factor being 1, 0.5 and 0.25 respectively. The results show that the response of the power transmission lines systems keep in the same, and then the windinduced vibration of the distorted model in the wind tunnel test can actually reflect the response of the power transmission lines system under the wind load.
LI Dongsheng , LIU Dongyan , PU Qingping
2009, 32(11):1334-1338.
Abstract:This paper studies the landslide mechanism by the analysis of accumulation form, topography and geomorphology, self structure and natural river system of Weijiagou coal gangue hill. The limit state function is established based on plasticity mechanics limit analysis upper bound theorem and Bishop slices method, combining reliability theory. The safety coefficient and reliability index of Weijiagou coal gangue slope is calculated. The plasticity limit analysis upper bound theorem can consider the interior stressstrain relation of soil, so the formula derivation process is stricter. It is the consideration of the variability of gangue parameters that making the evaluation result more reasonable.
SONG Zhenxi , WANG Liao , GU Wei , HUANG Chuan , CHEN Dayong
2009, 32(11):1339-1344.
Abstract:The paper selects septic tank nightsoil sludge as the study object, and conducts three treatments for nightsoil sludge anaerobic digestion reduction under 35 ℃ including CK treatment(without HBHII compound microorganism), T1 treatment(adding 0.005% HBHII compound microorganism in the original nightsoil sludge system) and T2 treatment(adding 0.005% HBHII compound microorganism after the nightsoil sludge was sterilized by pasteurism). It investigates the removal rate of total solid (TS), volatile solid (VS) and COD of the three treatments, and analyzes the main contents of nightsoil sludge before and after anaerobic digestion and the digestion efficiencies of them. The results indicate that the removal rates of TS, VS and COD of T1 are 46.03%, 49.96% and 47.06%, respectively, and there are 14.89%, 16.26% and 15.53% higher than CK, 6.63%, 8.02% and 11.90% higher than T2, respectively. There are significantly positive (p<0.01) relations between T1 and CK, and T1 and T2 in the removal rate of TS, VS and COD. The nightsoil sludge digestion efficiencies of CK, T1 and T2 are 34.69%, 51.09% and 43.05%, respectively and that of T1 significantly positive(p<0.01) differs from CK and T1 treatment. The results indicate that the corporate effect of the adding HBHII compound microorganism and the original microorganism of the nightsoil sludge system are helpful to the reduction of septic tank nightsoil sludge and it is feasible for directly adding HBHII compound microorganism to septic tank for the reduction of the nightsoil sludge in it.
REN Song , WANG Xinsheng , JIANG Deyi , LI Lin , WANG Chunrong
2009, 32(11):1345-1351.
Abstract:This paper conducts a comprehensive analysis on the structural factors and environmental condition factors that influence the longterm safety of the tunnels,and designs a longterm monitoring scheme of tunnels according to relevant norms.The longterm tunnel safety evaluation model based is dcve loped on the tunnel monitoring scheme. For the tunnel structure, this study evaluates the safety ratings with a single index, and develops the multiindex comprehensive evaluation model. As an integrated score, a quinary digit which contains six digits is inducted. Together with the evaluation of safety ratings, it can detailedly reveal the actual safety condition of tunnel structure. As to the tunnel operation, the weight of indexes is confirmed using AHP, and the membership degree of indexes was calculated by trapezoidal distribution membership functions. A fuzzy comprehensive evaluation model of safety is built. This model is applied to evaluate the safety of Jiahua Tunnel, which has achieved a good result.
XIONG Wenqiang , YIN Gang , LIU Qicheng
2009, 32(11):1352-1356.
Abstract:The current methods used to select the schemes for Cleaner Production in China have some disadvantages. This paper presents the Grey Correlation Analysis and constructs a new index system for Cleaner Production schemes. The environmental index, the economic index, etc., and technical index, are quantifyed and minimized. Each scheme is compared with the evaluation standard. The optimal scheme which has the largest correlation with the evaluation standard. The result shows that the Grey Correlation Analysis can effectively avoid the subjective bias on the scheme selection for Cleaner Production. Schemes for Cleaner Production selected by the Grey Correlation Analysis have better performance than those selected by the traditional method in terms of economic, environmental and technical indexes.
WANG Yujia , GOU Qian , XIA Zhining
2009, 32(11):1357-1362.
Abstract:The separation of primary amino acids in Radix Isatidis and its injection is performed by coordination interaction capillary electrophoresis with nonderivative direct UV detection. This study investigates the effect of concentration of Cu2+ and acidity of electrophoretic running buffer, separation voltage, injection time and the internal diameter of the capillary on separation and detection. Under the optimal operation condition, the two amino acids are qualitatively and quantitatively analyzed and its liner range, detection limit and reproducibility are investigated respectively. The results show that the content of arginine is 0.63 mmol/L and the content of proline is 25.7 mmol/L in the Radix Isatidis Injection. Under the same condition, the components of Radix Isatidis extracts are separated by the presented method. The mass fraction of arginine is 0.027 and the mass fraction of proline is 0.054.
LI Jing , LIAN Bin , HOU Weiguo
2009, 32(11):1363-1368.
Abstract:A bacterium strain, GY04, was isolated from sand soil of a maize field in suburb of Guiyang. The analysis of DNA sequence suggests that the strain of GY04 is Agrobacterium radiobacter. With the principle of the uniform design, the fermentation conditions of the strain GY04 are optimized. Analyzing by SPSS(V10.0), the optimal fermentation process is determined. They are beef extract 2.000g/L, glycol 2.775 g/L, calcium carbonate 2.000g/L, the initial pH7.000, the inoculum amount 7.000%. On these conditions, the production of the saccharide can be achieved the most, about (2.683±0.600) g/L. The results also show that bacterium A. radiobacter possess good waterretention ability as a microbial waterretaining agent.