bluuebunny/crossref_metadata_2025 huggingface dataset:
Taming a 0-1 knapsack problem with monkey algorithm
Authors: Xu Xiaoping , Xu Li , Zhang Xiao , Zhang Daqing , Luo Yi , Liu Long , Qian Fucai
Published: March 2020

Now, the 0-1 knapsack problem has a wide range of applications in real life, but it is a typical NP hard problem. thereby, solving the 0-1 knapsack problem has been widely concerned by many researchers. This paper puts forward an improved monkey algorithm where uniform distribution’s Kent chaotic map is adopted as the initial feasible solution of the algorithm, and the descending factor is used as the step size in the climb process of the algorithm. Finally, in numerical simulation, a 0-1 knapsack problem is solved using the presented method and other existing methods to show that the given method is effective.
An Empirical Study on the Early Warning Mechanism of Financial Business Cycle Based on the BP Algorithms
Authors: Dai Kaichuang
Published: March 2020

Among the various factors that had an impact on the economy, the influence of financial economic cycle is always better than that of other factors. With the development of the society and times and people’s pursuit of economic development, finance has become more and more profound for economic development. The emergence of these new factors directly leads to the continuous improvement on financial influence on the economy. This paper mainly studies the early warning mechanism of financial economic cycle based on the BP algorithm.
Value evaluation of high-tech enterprises based on Black-Scholes model -- a case study of Hikvision
Authors: Fan Wen
Published: March 2020

High-tech enterprises refer to enterprises that carry out research and development in the fields of high-tech and emerging technologies, form independent intellectual property rights and carry out corporate activities based on them. In the process of high-speed development, due to the needs of corporate mergers and acquisitions, listing and financing, high-tech enterprises The value evaluation is particularly important. This paper discusses the valuation of high-tech enterprises based on Black-Scholes model.
Improved Test Platform and Evaluation Scheme for Train Vehicle Ethernet Systems
Authors: Hu ZhengWei , Pan Shuo , Yuan ZhiPeng , Li XueZhen , Li Peng
Published: March 2020

Ethernet networks have been widely studied for vehicle transportation applications. However, most vehicle Ethernet test schemes only use single PC software or distributed hardwares, without comprehensive evaluation for the system framework.This paper presents a novel test and evaluation scheme for vehicle Ethernet systems. Industrial cards are adopted to formulate the hardware platform, while multiple softwares are included to evaluate the system performance with network flow prediction. Thus, the novel scheme has superior potentialities for system design and engineering applications.
Establishment of early warning index of local government debt risk -- taking Hubei province of China as an example
Authors: Xu Zhiheng , Zhu Fan , Fan Wen
Published: March 2020

With the enhancement of local governments’ public management functions and the continuous development of economic and social undertakings, the scale of debt has shown a trend of continuous expansion, and the hidden dangers related to local government debt have also become increasingly apparent, which has seriously troubled the finance at all levels and caused extensive concern from all sectors of society.
The Study of the Location Model and the Valve-closing Program of the Pipe-tube of the Water-supply
Authors: Ban Fuchen , Ye Lu , Hei Yueming , Wu Dan
Published: March 2020

The city water supply pipe network is an important part of the rapid development of the city, so the safety and the reliability of the operation of the water supply pipe network are also paid more and more attention. When the water supply pipe network is in the explosion accident, a large amount of water loss is caused. So the explosion positioning model of the water supply pipe network is particularly important for the actual accident situation which is encountered in the real life.In combination with the SCADA system, the location of the explosion accident is determined, the optimal scheme of closing the valve is established by combining the topological structure of the pipe network, the waste of the water amount is reduced and the emergency repair time is saved.
Analysis on Extreme Temperature and Precipitation Event in Dabie Mountain in West Anhui during 1960-2013
Authors: Zhao Yongmei , Cheng Xinyu , Luan Xiaoxiao , Luo Yuan
Published: March 2020

This paper adopts the daily maximum temperature, minimum temperature and precipitation observation data in 1960∼2013 of each county weather station in West Anhui to analyze changes of temperature and precipitation extremes in that area with linear method. Research shows: The days with nighttime and daytime extreme low temperature are decreasing obviously at the speed of 3.104 days/10 years and 1.157days/10 years. The decrease amplitude of days with nighttime extreme low temperature is 2-4 times of that in daytime. The days with nighttime and daytime extreme high temperature are increased at the speed of 2.529 days/10 years and 0.638day/10 years. The former has passed significance test, but the latter has not. The daily range is reducing at the speed of -0.076°C/10 years. The one-day maximum precipitation is rising at the speed of 3.411mm/10years, and five-day maximum precipitation is decreasing at the speed of -1.558mm/10 years; the days with moderate rain are decreased -0.176days/10 years; maximum continuous precipitation days are decreased -0.065 day/10 years; maximum continuous non-precipitation days are decreased -0.079 day/10years. However, the significance test has not been passed. The precipitation frequency in that area becomes smaller.
The design and software development of remote monitoring system for aerator
Authors: Zhang Zewen , Mao Wenwu , Li Cheng , Wang Dengkui , Zhang Yuanxiang , Liu Qian
Published: March 2020

Aerator is an aquaculture device extensively applied. It is mainly used to adjust dissolved oxygen content in the aquaculture water so as to guarantee fishes in the water will not be die from oxygen deficit. However, at present, the aerator requires higher for experience and has intensive work strength of aquaculture workers. In order to improve the reasonability, accuracy and convenience of aerator, this paper designs remote monitoring system and develops software of aerator based on Java Web and PhoneGap, including overall design of remote monitoring system, Java Web application, PhoneGap mobile frame application, SQL Server database application. It realizes remote monitoring of aerator through PC or smart phones.
The investigation of in-channel aquatic vegetation (IAV) effect on hyporheic exchange (HE) with the solute tracer experiment
Authors: Wan Jingfang , Li Qiang , Tang Bing , Ding Mengda
Published: March 2020

To explore and quantify the effect of in-channel aquatic vegetation (IAV) on hyporheic exchange (HE), the research with solute tracer method were launched in a homogenous sand bed flume. The experiments took 3 trials including one control trial and two subsequent trials with only dependent variable of emergent IAV’s canopy area. The hypothesis that that IAV area has the positive correlation with mean hydraulic residence time (HRT) and correspondingly negative correlation with mean rate of HE. Comparation of the experimental support the hypothesis. However, rate of HE shows negative correlation with IAV area increasing at initial period. It is speculated that phenomenon is caused by sediment mobility which changed water pressure diffidence and formed long seepage path under IAV area. The speculation requires further research. The exploration of the complex interaction between IAV and HE requires further is still in its infancy. This research provides the promising evidence to further investigation.
Comprehensive Analysis Method Based on Multi-attribute Fuzzy Granulation in Decision Evaluation
Authors: Zhan Feng , Fang Zhao
Published: March 2020

In order to solve the problem in the process of supplier selection and evaluation, in this paper, granular computing theory was applied to the supplier evaluation and selection with fuzzy algorithm and analytic hierarchy process (AHP) in this paper. By using attribute value discretization algorithm, the application domain is extended to the case where attribute value is quantitative, and the decision analysis method is constructed. This method combined the qualitative and quantitative information to build a comprehensive analysis method. It has constructed a decision analysis method to realize supplier evaluation and selection of multi-attribute group decisions based on concerns, so as to provide enterprises with appropriate suppliers. This paper was applied to the evaluation and selection model of suppliers to verify the accuracy and feasibility of the decision analysis method. The enterprise with appropriate suppliers was provided in this method, which strengthened the enterprise’s position in the supply chain, and then improved the core competitiveness.
An Empirical Analysis of the Influence Factors on the Automobile Intra-industry Trade in Guangzhou
Authors: Xie Xiuzhen , Huang Hongwu , Gao Fengjiang
Published: March 2020

As the pillar industry of Guangzhou, the automobile industry is getting larger and larger, and the level of intra-industry trade is increasing year by year. Through the empirical research of econometric models, it’s found that the automobile intra-industry trade in Guangzhou is mainly influenced by the following factors such as the average level of Guangzhou’s automobile market size, the RMB exchange rate, the scale economy of the automobile industry, the degree of trade imbalance, and R&D expenditure. Among them, the scale economy of the automobile industry and R&D expenditure are in positive correlation, while the other factors indicate a hindrance.
Ambiguity Function of Symmetric Triangular Frequency Modulated Continuous Waveform
Authors: Liu Jing , Zhou Xingang , Zhu Yanping
Published: March 2020

The ambiguity function of Linear Frequency Modulated (LFM) pulse compression signal has been discussed widely, but the ambiguity function of LFM continuous waveform (CW) is rarely heard about. In this paper, the Single Periodic Ambiguity Function (SPAF) of Symmetric Triangular Frequency Modulated Continuous Waveform (STFMCW) is analytically derived in an explicit form, and its Periodic Ambiguity Function (PAF) is obtained by the relationship between SPAF and PAF. According to both theoretical analysis and simulated results, it is obtained that the dominant feature of the SPAF about STFMCW is the intact X-shaped diagonal ridge and two halves with 3 peaks, and a low pedestal which has a shape of the figure “8”. Using the frequency-difference of up-sweep and down-sweep respectively, the range-velocity coupling can be eliminated for a moving target. And any cuts of SPAF or PAF of STFMCW can be gotten.
Study on transdermal drug delivery with microneedle array
Authors: Li Yan , Zhang Dawei , Zhang Peiyu
Published: March 2020

New pathways of drug administration have being explored because there exist weaknesses in the traditional drug delivery such as either potential degradation in the gut in oral method or pain and infection resulted from transdermal injection. Transdermal drug delivery (TDD) is a promising technology for drug administration. Among TDD, Microneedles (MNs) made transdermal drug delivery easier and more effective. The development of microneedles is necessary to eliminate or reduce the problems employing conventional needles such as pain, needle-stick injuries or needle re-use. In order to explore the drug delivery in human tissues, we made the hypothetical models of the flow of drug and to depict the flow and the moving ways of drugs. The delivering properties of drugs into skin tissue are analysed by adopting the previous hypothetical models. The results showed that the exiting velocity from the microneedle array played an important role to impact the efficiency of drug delivery. The large exiting velocity would accelerate the transdermal drug delivery and prompt drug into the circulation. In addition, the diffusion can be ignored due to a little influence.
Home energy management method for realizing demand response based on virtual power plant platform
Authors: Liu Tao , Zhang Jian , Li Siwei , Yue Liang , Zhou Xu
Published: March 2020

Demand-side management is an important measure to reduce peak load. This paper proposes a home energy management strategy based on a virtual power plant platform to achieve demand response. Ordinary household users respond to the electricity prices or incentives provided by the interactive platform of the virtual power plant, and adjust the time-transferable loads such as air conditioners, water heaters, and electric cars in the home to achieve the effect of reducing electricity expenditure while meeting the demand for electricity. The validity of the proposed method is verified by a numerical example.
Establishment of Petrochemical Process Security Simulation and Emergency Drill Platform
Authors: Li Lei
Published: March 2020

The petrochemical process is universally featured in large production scale, long process and multiple procedures, which lead to high difficulty in security simulation system establishment for petrochemical process and formulation of emergency plan. This paper puts forward a construction method for security simulation system modeling platform for petrochemical process, and the platform could provide the function of emergency drill. The platform could rapidly build simulation model through mechanism modeling and data modeling, and apply knowledge graph technology and semantic feature matching method to automatically analyze different emergency plans to acquire formal definition of plan and realize automatic plan selection. Compared to traditional method, the platform proposed in this paper could simulate different accident scenes and acquire effective emergency plans, providing effective assistance for emergency disposal decision making.
Research on Land Use Change in Hanzhong City Based on RS
Authors: Tong Shan , Ma Yifan
Published: March 2020

This paper studies the land use change status and development direction in Hanzhong City in recent years. The four remote sensing image data of Hanzhong City in 90 years, 00 years, 05 years and 10 years are selected, and the maximum likelihood ratio classification method is selected in ERDAS software. The land use types are divided into six categories, namely, forest land, grassland, water area, cultivated land, construction land, and unused land. The land use area changes, speed changes, and degree changes are analyzed. The results show that Hanzhong City has been used for 20 years. The area of forest land and construction land is increasing. The area occupied by water, grassland, cultivated land and unused land is decreasing. The annual rate of change in land use is low, and there is a tendency to rise first and then fall. From the comprehensive index of land use, Hanzhong The land use degree of the city is relatively high. Generally speaking, the land use of Hanzhong City is in an adjustment period and has a large development space.
Real-time data visualization method for oil pipeline monitoring based on Internet of Things
Authors: Wu Qian , Chen Xiaolong , Yu Haoyu , Liu Qiang , Yang Yanhong
Published: March 2020

With the increase in the number and length of pipelines in China, pipeline damage accidents are increasing as well. Traditional methods do not allow real-time monitoring of pipelines. The development of the Internet of Things has promoted the monitoring techniques and the development of pipelines. But a problem arises as to how to deal with the huge data generated by monitoring systems. This paper proposes a real-time data visualization method for oil pipeline monitoring based on the Internet of Things. In this method, the measurement nodes of the sensing layer collect the pipeline data and transmit them to the server of the application layer through the network layer. A web application is built based on Spring MVC in the application layer of the Internet of Things to process the data through the interaction between the front and the back. The data visualization algorithm based on Echarts and AJAX is used to position the pipelines and the real-time situation of pipeline anomalies. The results show that with this method, the program runs faster and has higher monitoring efficiency, and the poor readability problem of the oil pipeline data is solved.
A new Solution of the Fractional-order Singular Linear Time-Invariant System
Authors: Feng Zaiyong , Chen Ning , Wu Lingling , Zhang Yi
Published: March 2020

A new solution, the distributional solution of the fractional-order singular linear time-invariant control system (FOSLTIS) is studied in the paper. On the basis of proposing the definition of the Caputo fractional derivatives of Dirac function δ(t), the Laplace transform

L

[
0
C

D
t
α

δ
(
t
)
]
=

s
α

(
α
∈

R
+

)

was obtained, then

L

−
1

(

s
α

)

=
0
C

D
t
α

δ
(
t
)

(
α
∈

R
+

)

was derived. With regard to FOSLTIS, the system was decomposed into fast subsystem and slow subsystem by restricted equivalent transformation. Using Laplace transformation and taking

L

−
1

(

s
α

)

=
0
C

D
t
α

δ
(
t
)

(
α
∈

R
+

)

into account, distributional solution for the fast subsystem was obtained. Two examples illustrated the correctness of the distributional solution of the FOSLTIS.
A Collaborative Filtering Methods Based on Expected Utility
Authors: Zhang Tao , Zhao Kun , Zhang Xianhua , Zou Yan
Published: March 2020

In recent years, there has been a variety of improved collaborative filtering methods, which promote accuracy of recommendation by analysing too much user or item information like individual characteristics, application scenarios and so on. This increases the time complexity of the algorithm and leads to low efficiency of recommendation. Therefore, how to improve the quality of recommendation through analysing a small amount of effective information has attracted more attention in the research of collaborative filtering methods. This paper proposes a collaborative filtering method based on expected utility from the perspective of the economic significance of user rating. Firstly, the method establishes the corresponding similarity criterion and calculates the similarity between users or items by scoring expectation. Then, the nearest neighbour set is calculated and the final prediction is got. Finally, our method is validated by the experimental results using movielens-1m data set. The results show that the collaborative filtering method proposed in this paper is simpler and more feasible compared with the traditional IBCF, KNN and other mainstream methods, and can improve the efficiency and quality effectively of recommendation only using less information. This work has significance both in theoretical research and practical application value.
Evaluation of Ecological Vulnerability of Yulin City under the Background of Returning Farmland to Forests
Authors: Tong Shan , Ma Yifan
Published: March 2020

Yulin City Located in the Shaanxi Province Maowusu Desert and the northern Shaanxi Loess Plateau transition zone, its special geographical location makes the region a typical ecologically fragile area. Based on the “pressure - state - response" model, this paper based on the 14 indicators of soil erosion, population density, NDVI and so on. Based on the natural and human factors, the principal component analysis method was used in GIS and SPSS software. And the ecological vulnerability of the region for 10 consecutive years from 2003 to 2013 was evaluated with a pixel size of 100 m*100 m. The results show that the ecological fragility in the northern part of Yulin City is higher than that in the southern region and the ecological environment has improved in the past ten years. This paper discusses the relationship between ecological vulnerability and human activities, social development and natural environment, and provides reference and basis for ecological maintenance of Yulin city.
Research on the key technologies of the end-to-end intelligent dual live data center architecture
Authors: Yuan Gang , Wen Shengjun
Published: March 2020

As a direction of the current government informatization,dual live data center can be understood as both have a high availability architecture of production system, also is a kind of disaster information system construction model. Dual live data center can not only solve the government information system of business continuity and data reliability, but also can reduce the load balance of business requests and the resource operation pressures on production part.It can improve the effect of system efficiency and the user experience. But most of current dual live data center architecture is “not real dual live”, it is only dual live in some aspects, it will not have negative impact on system external service when the specific failure occurs. In this paper, an end-to-end “full dual-activity" system architecture is proposed. By building a dual-activity system at various technical levels, two fully dual-activity data center architectures are realized. The data center constructed by this technical route can be backed up and switched intelligently, It can deal with the vast majority of failures and disasters, and provides a more reliable guarantee for the safe and smooth operation of the government information system.
Development of Physical Simulation Experiment Technology for Blast Furnace Coal Injection Ironmaking
Authors: Zhou Xiaolei , Pu Song , Liu Ningbin
Published: March 2020

The coal injection process of blast furnace has certain particularity. Including gas movement, material movement, coal gasification process, coal combustion and other phenomena. However, the actual conditions of the laboratory are limited, and these phenomena need to be simplified. The key of physical simulation is to design the experimental model correctly. The basic theory of the correct design of the experimental model is the principle of similarity, that is, to establish the experimental model satisfying the main similarity conditions. So as to ensure that the main physical phenomena in the model and prototype are similar. A series of measurements were carried out during the experiment. Get the knowledge of the corresponding change law of the prototype. In the process of experiment, it is necessary to make sure that the model has the same number, material balance and heat balance. Otherwise, it is difficult to achieve the equilibrium state in the experimental process and obtain meaningful experimental results.
Optimization Design of CRC Circuit in UHF RFID Tag Baseband
Authors: Chu Qi , Tao Sha , Xiao Wan’ang , Gao Wanlin , Zhang Yan’e
Published: March 2020

Aiming at the requirements of EPC Class1 Generation2 (EPC C1G2) and the GB/T 29768 Information Technology Radio Frequency Identification 800/900MHz Air Interface Standard, the paper presented an optimization design of CRC Circuit in UHF RFID Tag baseband. First, the principle of CRC and RFID tag baseband structure are described; To optimize the power consumption and work efficiency of the cyclic redundancy check (CRC), the CRC unit is designed by parallel calculation and circuit multiplexing, then RTL-level coding and function simulation are carried out for the CRC unit; At last, using the SMIC 0.18μm process library to synthesize the logic circuit. The experimental results show that the optimized design is superior to the traditional serial circuit. The hardware area is reduced by about 29%, the timing is reduced by about 22.3% and the total dynamic power consumption is reduced by a small amount.
Research on the Application of Intelligent Construction Site in Construction Site Management
Authors: Zhang Meng
Published: March 2020

China’s construction industry has developed rapidly, and the traditional management methods can no longer adapt to the current construction projects. It has become an inevitable trend to change the management methods of construction sites by using information technology. The use of information technology to manage personnel and the site, and the application of intelligent worksite to the construction site, can better manage the site and bring more efficient management methods to the construction site. This paper mainly analyzes the quality and safety problems in the construction site, and uses the implementation methods of training, teaching and technical methods to reduce the quality and safety problems in the construction site with the help of the concept of intelligent construction site, so as to achieve the purpose of improving the management efficiency of the construction site.
Research on Control Strategy of Electric Heating Load Cluster
Authors: Han Ninghui , Li Dezhi , Lu Bo , Zhou Ying , Li Qing , Li Shupeng , Gong Feixiang
Published: March 2020

At present, due to the rapid development of the economy and the unceasing enthusiasm of the modernization process, human beings are increasingly dependent on electric energy. The development of renewable energy and energy efficiency have become the consensus in the energy field. The randomness of in the future solar power generation, wind power and other intermittent and new energy sources in the power grid continue to rise, which is bound to occupy an increasingly important position power energy structure. The active regulation capability of the “power supply side” in a high-ratio renewable energy grid is degraded. To ensure safe and efficient operation of the grid, it is imperative to develop the regulation capability on the load side. This paper establishes a cluster aggregation model, clusters the electric heating load through scientific and rational grouping, makes the electric heating load form a load group for unified regulation, formulates an appropriate cluster optimization control strategy, and makes full use of the cluster electric heating control potential to achieve peak clipping. Fill the valley, effectively improve the regulation capacity of the grid.
A Multi-parameter driving and measurement circuit of ultrasonic motor
Authors: Chen Ning , Fan Shixun , Fan Dapeng
Published: March 2020

In this paper, an integrated multi-parameter circuit is designed to meet the requirements of the ultrasonic motor for driving and measurement. The original signals are generated by the DDS method in FPGA. Then, to assure the purity of actuating signals, the linear amplifiers which operate with the transformers are chosen. Moreover, currents and voltages are obtained by their respective transformer modules, which are verified by the experiment results that the voltage measurement error can reach 1.3V, the current measurement error is 3mA, and the bandwidth can reach 60 kHz. Finally, the better actuating signals are obtained comparing with the traditional commercial driver and the repeatability of the parameter adjustments are achieved.
Development and Engineering Application of AC Charging Pile for Energy Internet Router
Authors: Xiao Yuhua , Wei Bin , Lv Peng , Kong Yun , Huang Jian
Published: March 2020

At present, in the context of the rapid development of green new energy and environmental protection requirements, it is of great significance to build an energy Internet ecosystem based on charging network and vehicle networking platform. In this paper, the system block diagram of ac charging pile of energy Internet router is given. At the same time, based on the overall scheme design, the control strategy of the energy Internet router ac charging pile is introduced in detail. Finally, the development of the prototype is given, and a demonstration application project of the energy Internet router ac charging pile is established in shanheyuan community, Yangzhou, Jiangsu province.
Key Technologies and Applications of Cloud Energy Storage
Authors: Zhu Yanping , Wu Ping , Fang Huanhuan , Zhang Yueguang , Xie Fei
Published: March 2020

Due to the fluctuation of electricity market price and intermittence of new energy generation, the demand for energy storage in the power system is also increasing. However, due to the high cost of energy storage construction and the long payback period of investment, users are not willing to build energy storage. Cloud energy storage is one of the development directions of energy storage in the future. This paper introduces the definition, characteristics and research status of cloud energy storage in detail, analyzes the relationship between cloud energy storage and distributed energy storage, summarizes the key technologies and business models of cloud energy storage, and prospects the future development of cloud energy storage.
Identification of electrical equipment based on two-dimensional time series characteristics of power
Authors: Jia Dongning , Huang Xianqing , Du Zehua , Li Ruixue , Li Kexin
Published: March 2020

Non-intrusive load monitoring provides real-time monitoring of the operational status of individual devices in the home and provides detailed power usage data. In this paper, a deep neural network structure with residual module and Batch Normalization layer is proposed for the problem that it is difficult to extract complete features. The new method of converting power data into two-dimensional image is used to identify electricity device. Finally, the accuracy rate of the test in the data set containing 21 kinds of electrical equipment is 97.2%. The experimental results show that the method has high recognition for a large number of household electrical equipment, especially for appliances with multiple states and fewer samples rate.
Review of integrated energy system under deep integration of cyber-physical system
Authors: Zhu Bingquan , Zhang Lijun , Xu Kangxuan , Zhang Xizhu , Hu Yishuang , Ding Yi
Published: March 2020

The safe and reliable operation of the integrated energy system (IES) under the deep integration of the cyber-physical system (CPS) relies on accurate modelling of information systems and energy systems. With the increasing requirements of the society on the operation of IES, it is very important to carry out corresponding modelling researches considering CPS. Firstly, this paper introduces the concepts of IES under deep integration of CPS. Secondly, the equivalent models for energy systems, information systems and integrated systems are pointed out, respectively. Finally, considering the correlation between information systems and energy systems, the future research directions of integrated cyber-physical energy systems are proposed.
The application of power quality signal de-noising based on the improved wavelet threshold function
Authors: Zhong LiangLiang , Wang Hanfeng , Xu Wei , Liu Yu , Wu Gang , Liu Chitao , Lin Shunfu
Published: March 2020

The contradiction between de-noising and preserving the local features of the original signal simultaneously cannot be solved with the traditional wavelet threshold function (TF), and thus an improved combination of soft and hard threshold functions (TFs) of power quality signal de-noising is proposed in this paper. The improved wavelet TF is utilized to overcome the problem of “Pseudo-Gibbs phenomenon”, the deviation of wavelet coefficients, caused by the traditional wavelet TF, which fills a gap for the deficiency of wavelet soft and hard threshold de-noising, and with stronger adaptability. Finally, the de-noising tests of three typical signals of power quality are simulated based on MATLAB R2016a. Compared with the traditional wavelet TFs, the results obtained based on the proposed improved wavelet TF can guarantee better effectiveness and feasibility.
Dynamic behavior analysis of backup protection for HVDC transmission line
Authors: Han Kunlun , Dai Yu , Song Haigen
Published: March 2020

The backup protection of HVDC transmission line consists of differential undervoltage protection and differential protection. In this paper, based on the actual parameters, the simulation model of differential undervoltage protection and differential protection for DC line is built. The response regularity of each criterion of the two protections under different fault conditions is studied. The basic functions of each criterion are defined, which provides an important basis for the setting calculation of DC line backup protection.
Research on Risk Assessment of Turbine Regulation System Based on Markov State Model and Entropy Weight Fuzzy Comprehensive Evaluation Method
Authors: Xu Jing , Cui Jiashuo
Published: March 2020

In recent years, the hydropower unit is developing towards high power, and large-scale, which increases the adjustment difficulty of the turbine regulation system. In addition, the turbine regulation system itself is a complex nonlinear system. The risk of system operation and risk assessment has become more complicated. This paper proposes a method to evaluate the operational safety risk of Turbine Regulation System by combining Markov State Model and Entropy Weight Fuzzy Comprehensive Evaluation Method. Firstly, the full-state operation model of the turbine regulation system is established. The Markov model is used to calculate the probability of fault occurrence. Secondly, the Entropy Weight Fuzzy Comprehensive Evaluation Method is introduced to evaluate the severity of the fault. Finally, a risk assessment system is established based on the probability of failure and the severity of the failure.
A Non-Intrusive Load Monitoring System Based on Blacklist Detection
Authors: Liu Zixuan
Published: March 2020

Electric utilisation safety is widely recognised as an important issue. Most electrical accidents can be concluded to the unallowed access of certain kinds of electrical appliances, hence can be effectively prevented by a blacklist-based detection. However, this ability is lacked in many of the existing Non-Intrusive Load Monitoring (NILM) system. This paper proposes a novel blacklist-based NILM system capable of extracting valuable information from the main wire when unallowed risky appliances are switched on in a household. Comprehensive methods are proposed to optimise the accuracy of detection and the self-learning ability on blacklist extension. Experimental results show that the proposed methods yield outstanding performance. The proposed system is applicable for unallowed appliances management, from the inhabitants or from the grid operator’s point of view.
Sensorless Control of a Tubular Oscillatory LPMSM based on MARS and Deadbeat Current Predictive Control
Authors: Lu Kang , Wu Tao , Chen Haonan , Wang He , Gao Jia
Published: March 2020

In the vector control system of the tubular oscillatory linear permanent magnet (PM) synchronous motor (LPMSM), it is difficult for traditional mechanical sensors to accurately obtain the feedback information under harsh conditions. In this work, a speed sensorless vector control system is designed and applied to the tubular oscillatory LPMSM which adopts the model reference adaptive system (MRAS), and the deadbeat current predictive control (DCPC) is also adopted to replace the traditional PI current loop to establish the coordination controller, which overcomes the difficulties of global optimization and PI control parameter setting. And the method is proved by the simulation results and it gets better dynamic performance.
The feeder outage prediction model based on Optimization and Improvement of Random Forests Algorithm
Authors: Zhu Jiajia , Zhou Lanbo , Lu Liming
Published: March 2020

The accurate prediction of feeder monthly fault level is the key to distribution network operation and maintenance. Aiming at the problems of low prediction accuracy, a method based on improved random forest to predict feeder monthly fault level is presented. Compared with the similarity calculation method of original random forest sample, this one increases the measurement of leaf node path distance, and applies the improved sample similarity to classification problem. Through the experimental comparison in the fault database of distribution network, the improved method can achieve a better classification effect than the original one, thus proving the effectiveness of the improved method.
Harmonic emission level evaluation method of photovoltaic system based on relevant vector machine
Authors: Yang Linghui , Yao Weiqiang , Pan Ling , Zhou Jian , Chen Ran , Feng Qian , Zhang Peng , Zhao Jinshuai
Published: March 2020

With the increasing connecting of photovoltaic systems, the harmonic pollution in power grid is deteriorated. The evaluation of the harmonic emission levels for photovoltaic system is significant for harmonic mitigation. However, when the background harmonics are unstable, traditional evaluation methods have large calculation errors. To solve this problem, a method based on the relevant vector machine is proposed in this paper. Compared with the traditional vector machine based method, the novel one can reach a high calculation accuracy, even when the background harmonics is relatively unstable. The validity for our proposed method is verified by simulation analysis.
Hardware Design of Non-contact Voltage Detector Based on STM32 Microcontroller
Authors: Zhang Xuemin , Zhang Peng , Shi Yuqing , Dang Junpeng , Yuan Liwei
Published: March 2020

In view of the time-consuming and labor-intensive problems of traditional contact electroscopes, this paper designs a hardware system of non-contact voltage detector based on STM32 single-chip microcomputer. The hardware design mainly includes signal amplification and conditioning circuit and power module, Wireless transceiver module, display and alarm module, etc. In order to reduce the distortion of electric field caused by human during measurement, a wireless transceiver module device is adopted, which has a simple structure and can meet the engineering requirements of the non-contact power inspection of the transmission line.
A Way to Evaluation the Process Immunity Time of Customers’ Sensitive Industries Processes
Authors: Xu Zhong , Mo Wenxiong , Luan Le , Guo Qianwen , Zhou Kai
Published: March 2020

The premise of voltage sag mitigation for sensitive industrial processes is to reasonably assess the economic losses caused by voltage sag. And the process immunity time is the key information in the process of economic loss assessment. Existing research usually obtains process immunity time through monitoring systems or overall testing. However, in the actual situation, due to various constraints, the traditional method of obtaining the process immunity time is inconvenient. To get PIT more conveniently, a sensitive process immunity evaluation method based on response information flow is proposed in this paper. This method regards sensitive industrial processes as a composite system. According to the function of each part of the system and the response characteristics of voltage sag, it can be divided into three modular combinations, which are delayed structure, competitive structure, and conductive structure. According to the delay time and module combination characteristics of module response to the voltage sag, the propagation path of response information flow caused by sag can be determined, and the process immunity time can be evaluated.Finally, a case study of the painting process of a car factory in southern China shows that the proposed method can be applied to the sensitive process immune time assessment.
A Novel Reconfiguration Strategy of Distribution Network
Authors: Sun Xuri , Li Yanzhen , Cui Mei
Published: March 2020

Distribution network reconstruction is important for the reliable operation of distribution network. This paper establishes a mathematical model by using random weight for multi-objective optimization. A new algorithm is proposed based on binary particle swarm optimization (BPSO) algorithm, which can quickly adjust topology and cut off load in limit state. The new algorithm improves the distribution network’s reliability with the advantages of lowest power loss, better load balance and highest power supply capacity. Finally, the performance of the proposed method is tested on IEEE 33-node power distribution system.
Study on Orderly Charging of Electric Vehicles Based on Time-of-use Electricity Price
Authors: Zhou Zhixin , Song Bin
Published: March 2020

The huge power grid load caused by large-scale centralized charging of electric vehicles is the main factor restricting the development of electric vehicles. At present, there is no definite method to reasonably allocate the charging load of electric vehicles to reduce the load of the power grid. Aiming at the problem of electric vehicles charging, a method of electric vehicles orderly charging is proposed. The model of electric vehicle charging is built, and the method of using time-of-use electricity price to guide users to arrange charging time reasonably is put forward, which meets the differentiated needs of users. In order to verify the correctness of the conclusion, the Monte Carlo method is adopted to simulate the charging behavior of users, and the orderly charging mode is compared with the original disordered charging mode. The results show that compared with the traditional disordered charging mode, the orderly charging method can reduce the load of the power grid and achieve the effect of peak load shifting. In addition, it plays a certain role in reducing user charging cost and increasing charging pile utilization efficiency.
Modeling and Simulation of ±10 kV DC Transmission System based on Mechanical DC Circuit Breaker
Authors: Cui Jiashuo , Qin Ke , Long Zhisong , Xiu Shixin
Published: March 2020

In order to simulate the interruption process of mechanical DC circuit breaker in actual DC power grid and obtain various stress characteristics of DC circuit breaker in actual interruption process, it is necessary to establish a stable and effective flexible DC system model with good dynamic performance. In this paper, the controller models of system level, converter station level and converter valve level are established for the 10kV flexible DC system, and then the steady-state characteristics and dynamic characteristics of power step of the system are simulated. After analyzing the variation of voltage, current and power and dynamic response speed of converter station, the simulation results show that DC voltage and active power of the system operate stably according to the reference value and the fluctuation error of DC voltage is less than 1%. The internal and external loop controllers all track the dynamic changes of their respective command values rapidly within 0.5s. The control performance of the flexible DC system model can meet the requirement of the interruption simulation of DC circuit breakers.
Short-Term Reliability Prediction of Key Components of Wind Turbine Based on SCADA Data
Authors: Liu Ketian , Zhang Jun , Su Feng
Published: March 2020

In this paper, the Principal Component Analysis (PCA) method combined with the Radial Basis Function (RBF) neural network is used to establish a short-term reliability prediction model for wind turbines based on the SCADA data. The PCA method is used to reduce the dimensionality of the SCADA data and extract the principal components as the input data of the RBF neural network. The RBF neural network is used to predict the running state of key components of the wind turbine. Finally, a short-term reliability prediction model of wind turbines based on PCA-RBF is established. With the real wind farm SCADA data, the short-term reliability of wind turbine gearbox is predicted. The result shows that the short-term reliability prediction model can better reflect the reliability of key components and provide reference for the operation and maintenance of wind turbines.
Analysis of resonance data in substations based on WOA- VMD-DWT
Authors: Si Hongxiao , Zhang Fang , Yu Xin , Yao Zheng , Li Chun , Zuo Tong , Liu Xiaoyu , Zhang Chunhua
Published: March 2020

Aiming at the problems of low accuracy and sensitivity to noise in existing substation harmonic data analysis methods, a method for analyzing substation resonance data based on WOA-VMD-DWT is proposed in this paper. Firstly, in order to reduce the effect of the subjective judgment uncertainty, the parameters of the VMD (Variational mode decomposition) algorithm are optimized by the WOA (Whale optimization algorithm). Secondly, WOA-VMD is used to decompose the signal into multiple modal components adaptively, and DWT (Discrete wavelet transform) transform is used to extract the instantaneous frequency and amplitude of each harmonic mode. Finally, the accuracy of the method is verified by simulation data. The results show that the method has obvious advantages which could extract each harmonic component accurately with high detection accuracy.
Power quality monitoring system of distribution room based on distributed sensors
Authors: Luo Junping , Han Liqun , Yuan Lulu , Li Bin
Published: March 2020

A large number of non-linear devices has been used nowadays. Therefore, the power quality problem on the user side is becoming significantly prominent. The power distribution room is the end of the power system, which is directly connected to the users. But distribution room has noneffective power quality monitoring system established due to difficulties of data measuring and installation. In this paper, based on micro distributed sensor with coil energy acquisition and wireless communication technology, a distributed power quality monitoring system is developed in distribution room, which can be implemented quickly and complete the monitoring and analysis of power quality information in the distribution room. The system realizes the function of design requirement through field test.
Research on PD-IoT Cloud Master Station Architecture Based on Blockchain Technology
Authors: Zhu Haipeng , Zhao Lei , Qin Kun , Li He , Wang Di , Zhang Shiwei
Published: March 2020

Blockchain technology is a new type of distributed database technology solution, which has unique advantages in terms of decentralization, security and transparency. These characteristics of the blockchain can solve some typical technical problems in the construction of the current power distribution IoT cloud master station. In this context, the architecture design and implementation of the power distribution IoT cloud master station based on blockchain is first discussed; then, the blockchain is integrated from three aspects: security performance, state estimation algorithm, and deep search engine. The new framework of the technology is analyzed. Finally, the application of the blockchain technology in the cloud master station of the distribution network is summarized.
Detection of quasi-circular vegetation patches using GF-2 image with tasseled cap and watershed transformations
Authors: Liu Qingsheng
Published: March 2020

It is a key to detect the quasi-circular vegetation patches (QVPs) for studying the establishment and encroachment mechanisms of the QVPs in the Yellow River Delta, China. A variety of spatial resolution remote sensing data have been used to map the QVPs. However, the adhesion between the QVPs with the QVPs or the vegetations of other shape makes the detection accuracy of the QVPs unsatisfactory. This study applied the decision tree classifier to map the QVPs using the brightness and greenness components of the modified intensity-hue-saturation pansharpened Gaofen 2 imagery. Then, the watershed transformation was used to segment the classification result. The final result was obtained using the thresholds of statistical features of the QVPs. It indicated that the method of this work could well detect the QVPs. In the future, more effective image segmentation algorithms should be used to deal with the over-segmentation in order to further improve the detection accuracy.