bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Denoising of Transformer Bushing Leads Based on IITD-WTD
Authors: Li Kai , Hao Chenggang , Zhang Jiguo , Sun Woye , Wang Xin
Published: August 2021

When conducting ultrasonic testing of transformer bushing leads, the detection accuracy is susceptible to noise, and it is difficult to accurately determine the state of the leads in the bushing. Aiming at the common noise pollution problem of casing ultrasonic echo signal, we propose an improved inherent time scale decomposition (IITD) and wavelet denoising (WTD) joint denoising algorithm. First, the ultrasonic echo signal is decomposed by improving the time scale; then, the wavelet denoising algorithm is used to remove the noise of each decomposed component; finally, simulation examples and experimental verification show that the signal-to-noise ratio is higher after denoising using the algorithm in the article, the average error is smaller, and the effective vibration information in the ultrasonic echo can be effectively retained. Therefore, the algorithm has certain practical value in engineering applications.
Analysis and Treatment of a Large Abnormal Vibration of 10 Watts in a 1000 MW Generator due to the Deformation of the Rotor End Winding
Authors: Yulei Yang
Published: August 2021

With the widespread application of large-capacity and high-parameter generators in the field of coal-fired power generation, there are more and more cases in which the vibration at both ends of the generator increases abnormally with load changes. This article introduces in detail the analysis and treatment process of the abnormal continuous increase of the 10-watt vibration of a 1000MW turbo-generator after it has been put into operation for two years. After the rotor returned to the factory for disassembly and overhaul, it was finally confirmed that the stacking of the full-size insulating tiles under the guard ring caused partial blockage of the winding deformation of the rotor end and the ventilation holes were the direct causes of abnormal vibration of the generator.
Detection method of inner lead wires of transformer bushing based on parameter estimation of ultrasonic echo model
Authors: Hao Chenggang , Li Kai , Zhang Jiguo , Sun Woye , Wang Xin
Published: August 2021

In order to solve the problem of low accuracy of the ultrasonic detecting method for the lead wires of the transformer bushing, this paper used the method of parameter estimation of the ultrasonic echo model to improve the accuracy of the ultrasonic flight time. First, this paper proposed an ultrasonic Gaussian model that suitable for detecting inner lead wires of transformer bushings, constructs a least-squares objective function, and then uses a particle swarm optimization algorithm to search for the optimal solution of the objective function globally, and proposes an algorithm for parameter estimation of the echo model. Finally, it is proved that the detection method proposed in this paper has the advantage of anti-noise interference through experiment, and the detection accuracy is improved. So, this method can detect the state of the lead wires in the transformer bushing.
Analysis on the Influence of Remote 110kV Substation on Transformer DC Bias
Authors: Zhang Lina , Yang Yunguo , Wang Peng , Hou Jiansheng , Sheng Jun , Dong Lingpeng
Published: August 2021

High voltage direct current (HVDC) transmission system has the advantages of large capacity, long distance and low loss. Relying on the advantages of HVDC transmission, China has established a large-scale energy transmission channel in the west, effectively solving the problem of uneven local energy distribution. However, HVDC transmission will generate ground current when it is operating in a single pole, which will cause the DC bias effect of the transformer. At this time, the core magnetic circuit of the transformer is saturated. Transformers will experience increased vibration, increased noise, local overheating, and surge in harmonics. This paper, based on the Jinhua HVDC transmission project as a background, established a power grid topology model in Zhejiang area based on the field-circuit coupling method. The focus is on calculating the DC bias of Shenze transformers in Jinhua area, and proposing treatment measures based on the calculation results. According to the actual measurement of the project, the accuracy of the calculation result is verified, which reflects the effectiveness of the governance measures.
The Partial Discharge Field Test of 1000kV Shunt Reactors
Authors: Li Jiansheng
Published: August 2021

Aiming at the insulation performance field diagnosis of 1000kV shunt reactors, the series resonant withstand voltage test equipment is developed. The test equipment mainly consists of the frequency conversion power supply, the excitation transformer, the series resonant capacitor, the wave blocking resistor and the voltage divider. The resonant frequency is between 30 and 300 Hz, the rated voltage is 1200kV, and the capacity is 1000 kW. During the test, the discharge is monitored at the high voltage bushing terminal and the 1000kV reactor insulation is analyzed. By using the developed test equipment, the 1000kV reactor in 1000kV Xuyi Station is tested, which verifies the validity of the on-site partial discharge measurement test.
The robust recovery model of distribution network considering correlation between wind speed and load
Authors: Mei Xiaohui , Zhao Chenxi , Liu Yan , Han Jianzhen , Zhao Haizhou
Published: August 2021

In order to consider the correlation between distributed power output and load, this paper uses the value-at-risk theory to quantitatively calculate the uncertainty of wind speed and load demand, and establishes a wind speed-load joint probability distribution model using bivariate normal distribution, which will take into account the wind speed uncertainty. The robust decision-making problem of reliability and load participation is characterized as a mixed-integer linear programming problem, which takes the minimization of the equivalent load loss as the optimization goal, establishes the load recovery path as the optimization variable, and takes the wind speed and load as the disturbance variable to account for the wind speed-The load-dependent robust restoration model of the distribution network is solved by the Gurobi high-efficiency solver. Finally, the IEEE69-bus power distribution system with wind power was used to verify the effectiveness of this model and solution method.
Study on Magnetic Field Shielding Effectiveness of Slotted Conductor Plate
Authors: Du Rongtian , Jiao Chongqing , Zhang Zhixin , Yang Yong , Wang Jialong
Published: August 2021

In this paper, the magnetic field shielding effectiveness of slotted conductor plate is tested. According to the dominant effect of magnetic shielding at different measuring points, the slotted conductor plate is divided into edge effect area, platform area and aperture leakage area, and the change law of magnetic field shielding effectiveness in different regions is analyzed. The magnetic field shielding effectiveness of slotted conductor plates at different frequencies is tested. The results show that the shielding effectiveness increases with the increase of frequency.
Research on Actual Road Emission Prediction Model of Heavy-Duty Diesel Vehicles Based on OBD Remote Method and Artificial Neural Network
Authors: Wang Jiguang , Wang Li , Ji Zhe , Qi Songbo , Xie Zhenkai , Yang Zhiwen , Zhang Xiaowen
Published: August 2021

In order to establish a prediction model of PM and NOx emission factors for heavy-duty diesel vehicles under actual road conditions based on OBD remote monitoring and big data, this paper carried out actual road tests on two China V heavy-duty diesel vehicles to obtain transient OBD and emission data by a Portable Emission Measurement System (PEMS) and self-developed On-board Remote Emission Measurement System (OREMS). According to the degree of influence of different parameters in the engine OBD on PM and NOx emissions, the principal component analysis method is used to extract the principal component parameters used to predict the model input, and the construction of a "Heavy-duty Diesel Vehicle Predictive Model based on Remote Monitoring Data and Neural Network Technology". Finally, the predictive model is trained and verified by PEMS test data. The prediction model provides new means and methods for the future development of large-scale heavy-duty diesel vehicle NOx and PM emission predictions under actual road operation.
Analysis of Instantaneous Collision Process of Axial Flow Check Valve Closing
Authors: Wang Ting , Zhang Yingjie , Kong Beibei , Wu Jialiang , Ni Xiaomei
Published: August 2021

When the pump stops suddenly, the axial flow check valve will shut down suddenly under the action of the medium pressure differential force, and the impact load between the disc and the valve seat will produce when the valve closes, which will have a certain impact on the structural strength and life of the check valve. In this paper, the display dynamics is used to simulate the impact process of the disc and the valve seat when the valve is completely closed. The dynamic response of the disc and the seat, the velocity of the disc and the energy change during the collision are obtained. The research has certain guiding significance for the practical application of axial flow check valve.
Simulation of Time Delay Characteristics of Time Sensitive Networking Based on MATLAB/Simulink
Authors: Tong GuoFeng , Li Jiang , Gao HuiSheng
Published: August 2021

In order to realize the optimal design of time sensitive networking flow scheduling strategy and meet the communication requirements of time sensitive applications to the greatest extent, it is necessary to conduct a comprehensive study on the delay characteristics by using effective simulation methods. Firstly, the working principle of time sensitive networking flow control mechanism and the influencing factors of time delay are analyzed, and the basic goal of simulation research on time delay characteristics is defined. Then, the technical characteristics of different network simulation methods are compared, and MATLAB/Simulink is selected as the simulation tool to design the time sensitive networking delay model and simulation algorithm. Finally, aiming at the main flow control mechanism application scenarios, the feasibility and correctness of the time sensitive networking delay simulation method based on MATLAB/Simulink are verified. The research results have reference value for the study of time delay characteristics and the optimization design of flow control strategy of time sensitive networking.
Power System Load Forecasting Method Based on LSTM Network
Authors: Luo CuiYun , Ling WuNeng , Mo Dong , Li YiMing , Li QiuWen , Liang ZhenCheng , Zhang Pan
Published: August 2021

Scientific load forecasting methods and accurate forecasting results are an important basis for the power system planning department work, as well as the basis and guarantee for correct decision-making on investment and construction. This paper has thoroughly studied the basic principles of recurrent neural networks and their shortcomings that they cannot solve long-term dependence problems, and a power system load forecasting method based on LSTM networks is proposed. Through the built-in two memory state lines of long term and short term, the problems that it is difficult to capture the long-term development trend and short-term fluctuation characteristics of data in time series prediction were solved. The results of case analysis show that this method can effectively improve the accuracy of power system load prediction.
Research on Collaborative Planning Technology of New Energy Power System
Authors: Deng JiaoJiao , Zhang LinNa , Li XuXia , Li Jia , Zheng XiaoMing
Published: August 2021

In this paper, the collaborative planning technology of new energy power system was intensively studied, and the model of collaborative planning of new energy power system was established after considering the power structure, power distribution, coordination and optimization of power grid, limited resources, peak load regulating of power system and access of new energy. The results of numerical examples show that this model can guarantee the safe and stable operation of the power system, reduce the cost of investment, and improve the capacity of the power system to absorb new energy.
Research on Safety Risk Evaluation Model of Bridge Construction Based on Analytic Hierarchy Process
Authors: Wu Changqing , Yan Yu , Yang Sijie , Huang Yuxin , Ren Xueying , Wu Hui , Dong E , Zhu Siyue
Published: August 2021

Bridges are the key to connecting the entire highway, directly affecting the economic and social benefits of the highway. In recent years, China’s highway bridges have faced such phenomena as frequent traffic accidents caused by heavy traffic, high vehicle loads, and fast speeds, and the severity of accidents has become worse. It is imperative to evaluate the safety of bridges. Bridge safety risk assessment is an important means to effectively prevent and reduce traffic accidents. Based on the in-depth analysis of the influencing factors of bridge construction safety, this paper determines the impact of bridge construction safety evaluation index system, on this basis, adopts the analytic hierarchy process (AHP), establishes a bridge construction safety risk evaluation model based on the AHP, proposes the impact the key factors of bridge construction safety, and provides a reference for improving the bridge construction safety in China.
New Energy Power System Coordination Simulation Method
Authors: Zhang LinNa , Li XuXia , Li Jia , Deng JiaoJiao , Zheng XiaoMing
Published: August 2021

The power system planning is of utmost significance for the grid's safe, reliable, scientific and sustainable development. A scientific, refined, reasonable and adaptive scheme is of significant economic value and social value. The author made innovation based on the traditional operation analog model. Facing the massive new energy access issue, the author has established the intermittent and random new energy power system coordination operation simulation method that adequately reflect the new energy output. The study herein lays a theoretic and technological foundation for the optimal operation of future power system and the medium-and long-term sustainable development for energy.
An Eigenvalues Method for Stability Analysis of Power Grid with Energy Storage Devices Based on Discrete Time Domain Model
Authors: Sun Rong , Wang Qing , Wang Weiyuan , Tang Xiaojun , Cheng Jinmin , Song Yunting , Li Zheng
Published: August 2021

The eigenvalue analysis based on state space model is an important method to study stability of power grid. With the large-scale access of energy storage devices and power electronics converters in power grid, the conventional state space modelling method suffers from complicated process of determining state variables and large calculation amount of eigenvalues, and nonlinear stability characteristics of power grid cannot be accurately reflected. To obtain the eigenvalues of power grid with energy storage devices more efficiently, this paper proposes a method for constructing state space model of power grid based on discrete time domain model (DTDM) and presents the corresponding stability criterion. Compared with the conventional state space modelling method, the nonlinear characteristics of components under proposed method can be linearized, and the constructed state space model can capture a wider range of system information including energy storage devices. Besides, the complete state space model of power grid can be obtained only according to the connection between component's DTDM and grid. Moreover, because eigenvalue solution under proposed method relies on the sparse grid node voltage matrix, the calculation of eigenvalues is simple and efficient, and it visually presents variation trend of eigenvalue and investigates the stability of system. Simulation results in Simulink/Matlab verify the correctness and effectiveness of proposed method.
Research and design of automatic silkworm cocoon harvester for plastic collapsible mountage
Authors: Liu Mochen , Zhao Qingji , Wang Guangrui , Li Fade , Tian Fuyang , Song Hualu , Song Zhanhua , Yan Yinfa
Published: August 2021

Silkworm cocoon harvesting manually from the plastic collapsible mountage is laborious, time consuming and inefficient, to overcome the present situation of cocoon harvesting, a novel automatic cocoon harvester with dual harvesting roller rotating in opposite direction for plastic mountage was designed. By analyzing the force on concoon harvested with the harvesting roller, conditional equation of cocoon separated from plastic moutntage was obtained, when the pressure on cocoon acted by the harvesting roller was lowest. The parameters that achieved efficient cocoon harvesting were:(1) the gap between the two harvesting rollers was 3 mm;(2) the diameter of the harvesting roller was 47.7 mm. When the harvesting roller speed was 700 r/min, 1100 r/min, 1500 r/min, one-hour continuous cocoon harvesting test was carried out. According to the experiment result, the cocoon harvester efficiency was about 8.7 times the efficiency of manual harvesting for the plastic mountage. The novel cocoon harvester can be promoted and used in sericulture areas.
Maintenance characteristics and bolt-mesh-anchor support technology of Large-span roadway in Guotun coal mine
Authors: shibao Shen , Huaixuan Cao , pan Li , renbao Zhao , haoran Lu
Published: August 2021

Aiming at the support difficulties of 1100 working face in Guotun coal mine of Shandong energy Linyi Mining Group, this paper analyzes the maintenance characteristics and support principle of large-span roadway, and puts forward the combined support scheme of bolt, mesh and cable combined with the actual geological production conditions. The field measurement shows that the deformation of roadway tends to be stable after 15 days, the accumulated subsidence of roof is 250 mm, the approach displacement of two sides is not more than 130 mm, and the floor heave is 80 mm. Therefore, the support scheme can effectively control the roadway deformation and ensure the safety production of the working face.
Research on the Control Strategy and Control Method of Ship’s Automatic Berthing
Authors: Shi Hankun , Wang Xuelin , Zhu Shenchao , Zhou Hongmao , Zhang Zhaolun
Published: August 2021

Ship berthing and maneuvering have become one of the difficult and complex maneuvers. With the development of large-scale, rapid, and automated ships, the navigation safety and efficiency of ships have become more and more important. In this study, the control problem of automatic berthing is studied and analyzed, and the control strategy of automatic berthing is compared and analyzed. This study uses dynamic output feedback control, robust control, neural network control and other methods to automatically berth under-driven ships. In the research of berthing control, a robust adaptive control method is proposed by combining dynamic surface control technology with backstepping method for the automatic berthing control problem of intelligent ships under the influence of environmental disturbance and quay wall effect. This method solves the problem of increased computational complexity caused by the traditional backstepping method for the virtual control derivation, and effectively eliminates the chattering phenomenon of the control output.
Research on the Testing Device and Method of Ship’s Automatic Berthing and Unberthing
Authors: Wang Xuelin , Shi Hankun , Zhu Shenchao , Zhou Hongmao , Guo Zhaosen
Published: August 2021

This research analyzes the test device and test method of the ship's automatic berthing and unberthing test, and creates an automatic berthing and unberthing test device. The device includes a test working condition setting module, a shore-based data communication module, a test data recording module, and a shipboard data communication module. The automatic berthing and unberthing test device can generate the traffic environment perception information of the area where the berth to be tested is located, and interact with the real ship berthing and unberthing system to obtain the berthing and unberthing commands. According to different test scenarios, this research is divided into testing and comparison of unberthing and berthing operations. The created test method can reduce the risk of actual ship testing, improve the safety of automatic berthing and unberthing.At the same time, it can completely realize the whole ship test process of berthing and unberthing functions.
Overview of One-Key Sequence Control Technology Based on Isolation Switch Equipment Detection
Authors: Wang Guanfu , Tang Junci , Liu Guangli , Zhou Jun , Wang Lipeng
Published: August 2021

This article introduces the one-button sequence control operation of the isolating switch in the intelligent substation, as well as the sequence control system architecture and different kinds of identification technology operation applications. Combined with actual engineering, different recognition technologies have been proven practical and innovative.
Research Progress of the Temperature Monitoring Technology of the Electric Joints in the Ring Main Unit
Authors: Liu Changhua , Chen Jin , Shang Qiongling , Pan Dongqiu , Chen Xiao , Yu Jie , Chen Zhongbin
Published: August 2021

This article summarizes several existing temperature monitoring methods for cable joints inside the ring main unit, mainly introducing infrared temperature measurement, fluorescent optical fiber detection, passive wireless surface acoustic wave temperature measurement, and wireless temperature sensor measurement. Then, the above methods were compared, and the advantages and disadvantages of each method were clarified. Finally, the research on the temperature monitoring method of the cable joints in the ring main unit is summarized. And the follow-up development direction of the passive wireless surface acoustic wave temperature measurement method in the temperature measurement of the cable joints of the ring main unit is prospected. It provides some reference for the research on the temperature monitoring method of the cable joints inside the ring main unit in the future.
Research on Comprehensive Decision-Making of Distribution Automation Equipment Testing Results Based on Entropy Weight Method Combined with Grey Correlation Analysis
Authors: Fu Yu , Zheng Youzhuo , Hao Shuqing , Miao Yu
Published: August 2021

The traditional evaluation process of distribution automation equipment relies on the judgment of experts. In order to solve the problem of insufficient objectivity of the comprehensive evaluation process, a comprehensive decision-making method of distribution automation equipment testing results based on entropy weight method combined with grey correlation analysis is proposed. Firstly, the test and evaluation index system considering eight big indexes and thirty-five small indexes is established. Secondly, the entropy weight method is used to determine the objective weight, which can avoid subjective influence and make the weighting process more objective. Then, the improved grey correlation analysis method is used to achieve the sorting of the test results of distribution automation equipment. Finally, the effectiveness of the proposed method is verified by the analysis and comparison of case studies.
Research on diagnostic method for broken tooth fault of reducer with involute helical gear
Authors: Shuai Zhang , Zhengfeng Wu , Huilin Zhang
Published: August 2021

This article takes the reducer with the involute helical gear as the research object, the diagnostic method of the broken tooth fault and the deterioration trend is researched by vibration spectrum graph, demodulation waveform graph, time domain waveform graph, demodulation spectrum graph. The research results show that vibration spectrum graph has the worst guidance for the broken tooth fault of the involute helical gear reducer, demodulation waveform graph has the poor guidance in the initial stage of the broken tooth fault, with the deepening of the severity of the fault, the fault characteristics of the waveform gradually become obvious, time domain waveform graph and demodulation spectrum graph are the effective means to discover the initial fault and monitor the fault changes.
A Remote Automatic Detection And Calibration Device for AC Watt-hour Meters
Authors: Tian Wen , Wang Xiaoyu , Yang Zuopeng , Li Qi , Sun Lipeng , Wang Di , Wang Zongjing
Published: August 2021

In this paper, a remote automatic detection method for AC electricity meter standard device based on cloud technology, wireless communication technology and automatic control technology is developed, to improve the work efficiency of large-scale AC electricity meter calibration. By optimizing the internal structure of the standard AC power meter, the grade of anti-shock and anti-vibration is improved. Through the integrated GPS positioning device, intelligent locking device and vibration label, the safety of the equipment itself and the traceability of the flow process are ensured. The cloud service system is further established to realize the remote automatic detection of the standard device of the electricity meter, which greatly saves the cost of manual calibration.
Development of three-in-one equipment for withstand voltage, partial discharge and dielectric loss
Authors: Su Xin , Liu Shuai , Liu Haiyang , Zheng Zhe , Qiu Shi , Lu Yue
Published: August 2021

Many major accidents in domestic and foreign power grids were caused by cable defects, causing huge economic losses and adverse social impacts. At present, the three main tests for cable testing are withstand voltage test, dielectric loss measurement and partial discharge measurement, which require different equipment for testing, which is low in efficiency and time-consuming. Among them, the very-low frequency method is suitable for the withstand voltage test, and the damped oscillatory wave method is suitable for the measurement of dielectric loss and partial discharge. This paper is based on very-low frequency cosine square wave and damped oscillatory wave technology, implements technology integration, and realizes the three-in-one detection of withstand voltage, dielectric loss, and partial discharge for cable.
Comprehensive monitoring cycle classification of centralized monitoring substations based on knowledge map and competitive neural network
Authors: Wang Jian , Zhang Yuze , Xu Yuanfu , Wang Weili , Li Saifeng , Wang Jianzhong
Published: August 2021

The influencing factors of the comprehensive monitoring cycle of the centralized monitoring substation are analyzed, including the voltage level of the substation, the frequency of centralized monitoring defects, equipment operation situation, the importance of the substation, the operation environment and the average load of the equipments. Those information can be obtained by constructing the knowledge map of centralized monitoring. On this basis, a comprehensive monitoring cycle classification method based on competitive neural network is proposed, and machine learning method is used to achieve a scientific and reasonable classification of comprehensive monitoring cycle of the substations. The simulation results show that the method is feasible and effective.
Design of Remote Monitoring System for Pre-Tightening Force of Anchor Bolts
Authors: Panfei Li , Qiankun Chen , Qi Zhou , Defu Zhang
Published: August 2021

Given the broad monitoring range and long monitoring time of anchor bolt loosening of draught fan, and harsh site environment in offshore wind power projects, a remote temperature and pressure monitoring system was designed in this study to realize the real-time wide-range monitoring of anchor bolt loosening of draught fans. The strain pressure transducer and platinum thermistor were used at the test end to acquire the pressure and temperature data, respectively. stm32f103 was used as the master controller in the acquisition system, hierarchical networking was conducted via Modbus protocol, and the long-distance transmission was realized by a fiber optical transceiver. LabVIEW was used by the upper computer to establish the client side to implement the data acquisition, storage and real-time monitoring.
Finite Element Analysis and Buckling Behaviour of I-shaped Beams with RHCFST Upper Flange
Authors: Ji Jing , He Lingjie , Xu Ming , Zhong Meihui , Jiang Liangqin
Published: August 2021

In order to analyse the buckling behaviour of I-shaped beams with rectangular high-strength concrete-filled steel tubular (RHCFST) upper flange, a total of 7 simply-supported beams are designed with height-width ratio of upper flange and span as the main parameters in this paper. Based on ANSYS software, the finite element models are established, and the eigenvalue buckling analysis of seven simply-supported beams are carried out. The buckling loads of the composite beams can be obtained and the influence of height-width ratio of upper flange and span on eigenvalue buckling loads of each order of the beams can be studied. The results show that the buckling loads of each order of the beams can be significantly improved with the decrease of the height-width ratio of upper flange and span. Height-width ratio of upper flange and span have greater influence on high-order buckling load of beams. When the first-order buckling mode of the beam is analysed, overall flexural-torsional buckling occurs and the overall linear displacement and angular displacement reach the maximum at the mid-span position of the beam. It can be concluded that the displacement of the beam is mainly out-of-plane displacement in Z direction, and the rotation of the beam is mainly in X direction. It lays a foundation for further nonlinear buckling analysis of such composite beams.
Automatic sealing technology for solidification line of medium and low level radioactive waste in nuclear powered ships
Authors: fengtian Lin , yu Wang , xuhui Zhou , haoqiang Zhu , jinying Xiong
Published: August 2021

The disposal of medium and low level radioactive waste in nuclear powered ships is increasing day by day. With the increasing requirements for nuclear safety and personnel protection, the intelligent disposal equipment should be improved to fully replace manual operations. The automatic capping technology in this paper can completely replace the original manipulator operation. With it, people can be kept away from dangerous working environments, thereby reducing the dose levels of the general population. The input of the device can also improve the safety and reliability of the whole operation line, thus improving the nuclear safety level of the solidification line.
Research on PD monitoring and location method of automatic directional substation
Authors: Hou Jie , Zhang Yanjun , Xu Su , Zhang Ruiqiang , Li Jiqiang , Xu Changjian
Published: August 2021

The accurate positioning of partial discharge can effectively avoid the occurrence of insulation failure of power equipment, but most of the existing positioning devices are fixed antenna array, which is difficult to achieve multi angle discharge monitoring in space, and the positioning method is single and the positioning accuracy is not high. Therefore, this paper proposes an automatic directional monitoring device for partial discharge source, and proposes a precise positioning method based on fixed point iteration method. With this positioning method as the main method and the automatic directional device as the auxiliary method, the spatial multi angle positioning of partial discharge source is realized. Firstly, PD signal recognition algorithm is used to identify the fault of PD signal, and then the steering gear rotation angle is determined by the angle correlation calculation formula, so as to accurately identify the position and direction of PD source. On this basis, four antenna array positioning algorithm is used to accurately locate PD source. Finally, through the field simulation test, it is found that the angle error of automatic orientation is 3°. The position error of PD source is 0.19m, which verifies the feasibility of the proposed method and device.
Experimental Management Study on Physical Influence Model of Wave Nearshore Mutational Terrain
Authors: Li Ma Chang , Peng Dong , Yong Jing
Published: August 2021

The influence of nearshore mutational terrain on wave was experimentally studied via local-global physical wave model. It was discovered that the influence of submarine topography on wave was mainly manifested by the change in wave height, which was especially apparent when the submarine slope gradient changed greatly and presented approximate mutation. Moreover, the differences of different wave directions and different wave elements in influencing the wave heights with different accumulative frequencies were presented. Therefore, the influence of nearshore mutational terrain on wave should arouse high attention in the engineering construction.
How does the control logic influence the establishment of a data-driven chiller model?
Authors: Qiu Shunian , Li Zhenhai , He Ruikai , Li Jiajie , Li Zhengwei
Published: August 2021

The modelling of chiller performance is critical for chiller optimal control, and fault detection and diagnosis (FDD). Different kinds of chiller models including sophisticated mechanistic models (white-box models), purely data-driven models (black-box models like artificial neural networks, ANN), and semi-physical models (grey-box models like empirical equations) have been proposed and tested. Due to the development of machine learning techniques, data-driven models have become more popular recently. The performance of the established data-driven model (accuracy, robustness, generalization) could significantly affect the model application. To enhance the model performance, a lot of studies have been carried out on investigating and modifying the model structure. However, the influence of the data quality on model training has not been sufficiently studied. When adopting historical data to train models, the data distribution is highly correlated to the control logic. So how does the control logic influence the establishment of data-driven chiller models by affecting the data distribution? In this study, experiments are conducted on an air-cooled chiller under model-free stochastic control to acquire rich and variable operational dataset; then the dataset is grouped into three corresponding to different chiller control logics. Finally, three models trained by three training datasets are evaluated, and the results suggest that when establishing data-driven chiller models, preliminary stochastic operation is cost-effective to acquire rich data for robust chiller modelling.
Study on Water quality Monitoring Method of Jialing River based on Sentinel-2 MSI Sensor Data
Authors: Lv Yingxue , Tian Zhen
Published: August 2021

Remote sensing monitoring has become an important means to evaluate urban water status, which plays the key role in maintaining the balance of urban ecological environment. In this study, based on the Sentinel-2 MSI sensor data, an inversion model of water quality parameters was established to monitor the concentration of chlorophyll a and suspended matter, and turbidity in some sections of the Jialing River. The results show that the inverted water quality parameters in this study are all within the normal range, and remote sensing technology can be effectively applied to regional water quality monitoring.
Development and implementation of standardized measurement and control system
Authors: Yujie Yang , Xian Zhang , Yongyong Duan , Jinsong Xue , Yadong Zhao
Published: August 2021

At present, due to the variety of product models and the increasing production data, the existing single machine based tester can not meet the needs of production. This paper introduce how to design and develop a centralized measurement and control system for servo products through standardized design and craft configuration.
Research on Machine Learning Optimization Algorithm of CNN for FPGA Architecture
Authors: Zhao Xiaodong , Zhang Xunying , Yang Fan , Xu Peiyuan , Li Wantong , Chen Fayang
Published: August 2021

In order to meet the application requirements of deep learning detection and recognition algorithm for Field Programmable Gate Array (FPGA) computing structure, this paper proposes a machine learning optimization algorithm of convolutional neural network (CNN) based on pruning and Int8 quantization. By analyzing the machine learning intelligent recognition network, the Yolo v3 target detection network is selected to verify the optimization algorithm. Aiming at the Yolo v3 network with balanced speed and precision, the optimization algorithm is studied in detail. Based on Amazon Cloud FPGA EC2 instance platform and ZCU104 FPGA hardware platform, machine learning optimization algorithms are used to accelerate the application of Yolo v3 network detection and recognition. Satisfactory results are obtained on both FPGA computing platforms. The experimental results show that the machine learning optimization technology can improve the inference speed of neural network based on both FPGA platforms. The network structure optimized by pruning and Int8 quantization algorithms can achieve high acceleration speed, with very limited accuracy loss.
Fault mode analysis and simulation verification of hydraulic system based on AMEsim
Authors: Ma Qi , Song Dong , Liu Bobing
Published: August 2021

This paper studies the relationship between the fault modes of hydraulic system and their flying parameters according to the principles of hydraulic systems. Based on the study of the working principle and composition architecture of the hydraulic system, the AMEsim software is used to construct a simulation model of the hydraulic system, to analyse the fault modes and mechanisms of key components in the system and their failure effects, and to establish a link between the fault modes and the flying parameters according to which practical evaluation parameters are provided for the subsequent monitoring and handling of system failures.
The design of remote data exchange system for Intelligent pharmacy
Authors: Lan Cao , Xiang Li , Yixuan Sun , Binxia Yuan , Jianbeng Liu
Published: August 2021

To achieve the intelligent management of drugs in pharmacy, a remote data exchange system is designed. Based on Labview, the software of doctor side and pharmacy side is designed. According to the demand of smart pharmacy, the software are divided into various functional modules, and then the workflow of each software module is designed. By using TCP/IP protocol, the remote communication between the doctor and the pharmacy is realized. By using th Access database technology, it can realize the functions of data storage and data real-time display in the whole intelligent pharmacy system. Finally, experiments were performed and the results showed that the doctor can issue prescriptions through this system; Pharmacy can automatically receive prescriptions, and update it to uniform drug database.
Research on calculation model of penetration depth when anchor touches Seabed
Authors: Li Xuedong , Hou Zhiqiang , Lu Juncheng , Yang Dongxu , He Zili , Cao Zhaonian , Zhao Guo-qing
Published: August 2021

In order to provide a reference for the safe buried depth of underwater pipeline in the navigable waters, this paper on the basis of the famous penetration formula, studied the calculation model of ship’s anchor dropped to seabed. The model considers the main factors that affect the penetration depth, such as the type of anchor, the weight, the speed of bottoming and the substrate condition. The model makes clear the bottom coefficient values, shows the method of hall anchor’s velocity of touching bottom and cross sectional area, and combines with the existing cast anchor experiment results to determine the shape factor of anchor. Using the calculation model, typical scenario was calculated and the calculation result of different methods were compared. The results show that the calculation model is better ease and compliance. It is very important to study the factors affecting the penetration of ship anchor and to determine and evaluate the buried depth of underwater pipeline in navigable waters.
Research on grid load model based on SPACK architecture of power big data
Authors: Xin Rui , Jiang Dan , Liu Hong , Chen Xi
Published: August 2021

Big data service is the key to the construction of smart grid, and the method of analyzing electricity consumption behavior based on improved AP clustering and the method of forecasting electricity load based on random forest is proposed. To address the problem of high complexity of AP clustering analysis, the entropy weight method is used to establish the index weights and improve the similarity calculation method to realize the fast and accurate analysis of customers’ electricity consumption behavior. For the problem of power load prediction, the fuzzy C-means method is used to construct the index weights. The fuzzy C-means is used to construct the historical similarity daily sample set, and the random forest is used to predict the electric load. The SPACK multi-level data processing framework is proposed to meet the needs of parallel processing speed for large amounts of data. The simulation results verify the effectiveness of the method proposed in this article and the important guiding price for the Power grid.
Semi-automatic apparatus of the permeability coefficient for cutoff walls in expansive soil areas
Authors: Zhang Min , Shen Xizhong , Lan Yan , Dong Chenghui
Published: August 2021

The permeability coefficient of most cutoff walls with plastic materials is less than 10−6 cm/s, it exceeds the measurement range of the existed devices. For the permeability coefficient testing for cutoff walls with low permeability, there are complex in the automatic system of pressure control, difficult in the keeping stability of hydraulic pressure, high in the measurement precision, leaky in the contact surface between the fixing apparatus and the measured specimen. Firstly, based on the characteristic analysis of cutoff walls, the hydraulic pressure was accurately controlled when the valve of atmospheric pressure control with high precision worked in with the electromagnetic valve, the hydraulic pressure was controlled. Secondly, the shape of inner space for the fixing apparatus of the specimen is developed, the leakage of the contact surface between the fixing apparatus and the specimen was greatly decreased. The test showed that the semi-automatic apparatus could realize automatic control of the hydraulic pressure accurately with the combined action of an electromagnetic valve and a pressure reducing valve, the leakage of the contact surface could be basically avoided. The testing apparatus can be used in penetrability tests and detection of project quality for cutoff walls with low permeability.
Evaluation Model of Grain System Based on AAQN Index System
Authors: Ge Ying , Chen Wen , Zhang Yinxuanye
Published: August 2021

According to UN FAO, global food production in 2019 reached 2.722 billion tons, showing high profitability and efficiency levels[1]. However, while we enjoy fresh and nutritious food, people in Africa and Central Asia are suffering from starvation and nutritional deficiencies. Despite the high profitability and efficiency levels, the existing food systems are challenged by equity and sustainability problems. In order to assess the current food system and propose a rational optimization approach, we propose a linear and hierarchical food system based on the priorities of food flow and distribution. To quantify food security based on food systems, we develop the AAQN Index system to measure the affordability, availability, quality& safety, and natural resources& resilience of a food system based on the Global Food Security Index (GFSI). We select 68 indicators and calculate the indicator weights by combining the entropy weight method (EWM) with GFSI. By systematically clustering the calculated results, we classified the food systems of 113 countries/regions into: excellent, normal, and poor. Then, we adjust the priorities of the Indian food system, a poor food system, to reveal the differences before and after optimization. Finally, by predicting the future AAQN Index of Indian through Grey Relational Analysis.
A Intelligent Portable Manager for Health: Study Design
Authors: Ye Xuewei , Ye Xufang
Published: August 2021

The immune function of the middle-aged and elderly groups is decreased, and they are easy to be infected with the virus, and once infected, they are easy to be turned into acute and critical patients with a high mortality rate. In addition, China’s aging population is becoming more and more serious, and the middle-aged and elderly population is a high incidence of all kinds of respiratory or cardiovascular system diseases. Most middle-aged and elderly people have more than one chronic disease at a time and need medication to treat it, and the type and amount of medication taken daily is often variable. However, due to the common problems of memory loss and blurred vision among middle-aged and elderly people, the various number and types of medication may lead to the possibility of the elderly taking it by mistake, missing or wrong, which may easily lead to the hidden danger of medication safety. This design will be health inspection management, medical interconnection, pharmaceutical affairs management, three main feature set in one, its realization storage service remind, interactivity, and index detection, do medicine detection and the sharing of data, realize the visualization of medical Internet, providing personalized family health management services, and the spread of interactive public medical basic knowledge.
Design of power decommissioning material management system based on RFID technology
Authors: Li Yang , Huang Xiaoming , Lin Minghui , Gao Ming , Yue Heng , Ding Jing
Published: August 2021

Due to the existence of many interference factors, the recognition rate of the existing power decommissioning material management system is low when reading material labels, so a power decommissioning material management system based on RFID technology is designed. In the hardware part, RF transmitting circuit and receiving circuit are designed to collect and process the specific information of decommissioning material tags in real time. In the software part, the main performance requirements of the system are determined according to the business process of power decommissioning materials management. Radio frequency identification technology is used to identify the communication tag of decommissioning electrical materials, and the system function module is designed to realize the data transmission between the system function module and the non-contact communication tag. The experimental results show that the label recognition rate of the system designed in this paper is 10.08% and 6.17% higher than that of the management system based on one-dimensional bar code recognition technology and twodimensional bar code recognition technology, respectively. The system has good ability of reading and identifying the labels of decommissioning materials, which is conducive to improving the information management level of power enterprise.
An enhanced second order prediction using the statistics of image difference signal for HEVC
Authors: Su Xiaoyu
Published: August 2021

This paper presents an enhanced second order prediction (ESOP) algorithm using the statistics of image difference signal. The algorithm can selectively control the residual of the first inter prediction for the second intra prediction. Unlike other second order prediction (SOP) algorithms, our proposed algorithm employs a check-strategy to adaptively select the residual of the first inter prediction for the second intra prediction so that the correlation between residual pixels can be kept close to the allocated accurate prediction as much as possible. Experimental results show that under the same condition, on average, the PSNR is increased by 0.40dB and the bit rate is reduced by 6.15% as compared with traditional second order prediction for QCIF and CIF sequences. This selective algorithm is particularly suitable for dealing with video contents containing complex motions in video compression.