bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Different Irrigation Patterns and Covering Methods on the Growth Characteristics of Onions in the Hexi Corridor
Authors: Deng Haoliang , Wang Peng , Xiao Rang , Zhang Hengjia , Li Fuqiang , Zhang Yongling , Yu Haiying , He Wenbo
Published: February 2021

In order to investigate the influence of the growth characteristics of onions in the Hexi Corridor, this paper tested the growth characteristics of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the growth characteristics of onion was measured in each reproductive period, and the results showed that: The transverse diameter and longitudinal diameter of bulb showed a decreasing trend with the increase of regulation deficit range. The transverse diameter and longitudinal diameter of bulb in T3 treatment were significantly lower than those in T1 and T2 due to the large amplitude of regulation deficit in the whole growth. There was no significant difference between T1 and T4, but it was significantly larger than T5. Moderate deficit and fine sand mulching were not conducive to the growth of bulb transverse diameter and longitudinal diameter.According to the growth characteristics of onion, the best regulation of onion growth can be achieved by covering the whole growth period with black plastic film and sufficient irrigation, which has theoretical guidance and reference significance for onion planting in Hexi irrigation area.
Strategic Analysis of Integrating Ecological Concepts into Garden Landscape Design
Authors: Gu Feng
Published: February 2021

With the current social and economic development and the acceleration of urbanization, garden construction has begun to attract more and more attention from the society. In the process of garden construction, landscape design is a very important section, especially under today’s green ecological concept, garden ecological landscape design is even more important. Based on this, this article analyzes the integration of ecological concepts in the process of garden landscape design, so as to provide corresponding references for garden design and its development.
Three-dimensional Visual System of Airport Site Selection based on SuperMap
Authors: Lv Jihong
Published: February 2021

Traditional airport location work mainly relies on 2D CAD drawing to draw and express the intersection relationship of multiple three-dimensional planes in space. In this way, the mapping speed and update are slow. And it involves more professional knowledge. It is difficult for non site professionals such as the planning department and the government to understand. They still use the method of manual on-site measurement points to calculate the excavation and filling volume, which makes the site selection work and earthwork volume calculation in the site selection stage time-consuming and laborious. In this paper, the airport model based on CAD design drawing and the three-dimensional real scene model of the site to be selected based on photogrammetry technology are established. The two-dimensional GIS analysis function and three-dimensional GIS visualization function of SuperMap are used to realize the high integration of two-dimensional data and three-dimensional GIS, and the three-dimensional real scene model of airport with superimposed design drawings is established, which is used for the evaluation and display of airport site selection.
Study on Mix Proportion Optimization of Nano-TiO2 Composite Photocatalyst for Pervious Asphalt Pavement
Authors: Xudong He , Fan Zheng , Zhihang Yang , Guojun Zhang , Yidong Xu
Published: February 2021

By using exhaust gas concentration tester, the degradation efficiency and mechanism of asphalt pavement coated with nano-TiO2 composite photocatalyst (TCP) has been analyzed. The results showed that the addition of dispersant greatly reduced the amount of TCP under the condition of similar degradation efficiency. When the optimum coating amount of TCP is 500g/m2, the degradation efficiency reaches 76.39%. As shown by scanning electron microscope, the TCP without dispersant will aggregate and exhibit uneven dispersion, while the TCP containing dispersant does not have this phenomenon, which indicates that TCP have a better exhaust gas degradation effect after being mixed with dispersant.
Study on the Evaluation of Surrounding Rock Stability and the Criterion of Limit Displacement of Fractured Stratum Tunnel
Authors: Chen Shuang , Guo Hongyan , Su Junwei , Tang Dengzhi
Published: February 2021

Displacement of fracture formation for highway tunnel surrounding rock stability and limit the problem of value, of deep buried tunnel by FLAC3D and the plane model is established, through strength subtraction, get tunnel vault subsidence and peripheral convergence value, secondly, based on the presence of fault cases surrounding rock ultimate shear strain analysis, it is concluded that with the loss of the reduction factor, tunnel inverted arch and arch foot site first achieve ultimate strain value and the limits of tunnel surrounding rock integrity buckling safety factor is 1.40, the fracture formation of tunnel surrounding rock stability safety factor than under the condition of no fault, lower limit displacement value than under the condition of no fault.
Analysis on construction stability of shallow tunnel with unsymmetrical pressure and small clear distance
Authors: Wang Zheng , Su Wanying , Liu Zhen , Bao Junchao , Ba Wenwen
Published: February 2021

Taking Georgia’s E60 Highway No. 3008 tunnel as the engineering background, a finite element calculation model was established for the construction stability of the shallow buried and unsymmetrical section of the tunnel exit, and the slope displacement and deformation and the construction dynamic characteristics of the supporting structure were analyzed. Finally, through analysis, the dangerous parts in the construction process are obtained. The analysis results show that: it is safe and feasible to simultaneously excavate the entrance section of the tunnel with unsymmetrical pressure and small spacing using the full-section method. The slope settlement process roughly goes through three stages: rapid change stage, slow change stage, stable stage, and the position stability of the slope toe is more sensitive to the overall construction of the tunnel. The maximum vertical settlement occurs at the position of the vault at the end of the tunnel, and more attention should be paid to this position during the construction. The research results can provide a certain theoretical reference for the construction of similar road tunnels in Europe.
Experimntal study on sludge solidification in a landfill site in Shenzhen
Authors: Gan Yu , Su Shengxi , Guo Jing , Huang Jie , Ding Jihui
Published: February 2021

As urban land use is relatively tight, the rational use of sludge landfills has become a problem that must be solved. Because the sludge has the characteristics of high water content, poor permeability, strong flocculation, high combined water content, and high organic matter content, the traditional vacuum preloading method, stacking preloading method and other curing methods are too inefficient and can not meet engineering requirements. In this paper, an indoor electroosmosis drainage consolidation test was designed for sludge in a sludge landfill area in Shenzhen. The test results show that the reasonable drainage method, stacking method and shortening the electrode spacing increase the strength of solidified sludge by 1.1 times, 1.6 times and 2.8 times. The water content is reduced by 19.8%, 25.5% and 55.6%.The drainage rate is linear with the current.
Construction Stability Analysis of the Portal Section of Georgia’s E60 Highway Tunnel Based on Numerical Analysis
Authors: Zhu Hanwen , Ba Wenwen , Bao Junchao , Wang Fuhua , Ding Libo , Song Zhanping
Published: February 2021

Combined with the construction of the No. 6 tunnel of the Khevi-Ubisa-Shorapani- Argveta section of Georgia’s E60 highway, the Midas GTSNX software was used to simulate the stability of the tunnel portal section during full-face construction. This paper analyzes the characteristics of displacement and stress variation of the tunnel portal slope during the whole section construction, the deformation law of surrounding rock during the whole section excavation, the deformation law of the initial support and final lining structure of the tunnel. The results based on the numerical simulation analysis show that when the entrance section of Georgia Tunnel No. 6 adopts full-face construction, the displacement of the supporting structure and the rock mass at the 5 m in front of the tunnel entrance changes greatly. Therefore, it is recommended to complete the invert construction of the tunnel before construction to ensure the safety of the tunnel entrance section; As for the entrance section as a whole, during the full-section construction process, the side slope of the entrance, the surrounding rock of the tunnel, and the supporting structure are all in a relatively stable state. Therefore, the full-section excavation of the No. 6 tunnel entrance section is safe and feasible.
The Application of Structural Health Monitoring in Different Engineering Fields
Authors: Jiawei Zhong
Published: February 2021

Recently, SHM is applied not only in civil infrastructure aspect, but it is also applied in buildings and aircraft maintenance and many other aspects, which is fundamentally used in our daily life. But, as it is becoming more and more significant in structural health, we are on an urge to apply it in more different fields, and a valuable attempt is found to bear in archeological field. In the process of providing existing applications of SHM, the subsequent articles in this theme are cited in an effort to show how SHM is used in many kinds of circumstances. In conclusion, technical challenges that must be addressed if SHM is to gain wider application are discussed in a general manner.
Monitoring and analysis of land subsidence in modern Yellow River Delta using SBAS-InSAR Technology
Authors: Han Yao , Zhao Yang , Zhang Yongwei , Wang Xinbing , Wu Limei , Ding Pengpeng , Jin Lihua
Published: February 2021

Modern Yellow River Delta has become one of the areas with serious land subsidence disaster in the plain area of Shandong Province. In this paper, Small Baseline Subsets - Interferometry Synthetic Aperture Radar (SBAS-InSAR) technology was used to process the Sentinel-1A data from August 2018 to October 2019 in the modern Yellow River Delta, in order to obtain the range and rate of land subsidence in the study area. At the same time, use the Leveling results of the same period to verify the accuracy. By selecting four larger land subsidence rate as feature points to analyze the characteristics of surface time series deformation, the influencing factors of land subsidence in this area are found out. The results show that during the past 2018-2019 years, the land subsidence in the the Yellow River Delta area was mainly distributed in Xianhe Town, southern the Huanghekou Town, Hubin Town, Guangrao County and its surrounding areas, DaWang Town, Yingli Town, Yangkou Town and the western part of Binhai Township, the most serious subsidence area is located in Xianhe Town, with an annual settlement rate of -204.7 mm/a. The land subsidence in the Yellow River Delta is mainly affected by groundwater overdraft, and the distribution characteristics of land subsidence funnel and deep groundwater depression funnel are basically consistent. In addition, natural factors such as consolidation of Quaternary loose sediments and regional tectonic movement also exacerbate the occurrence of land subsidence.
Multi-source spatial-temporal information fusion for urbanized watershed flood hazard risk assessment
Authors: Yi Shanzhen , Len Chuang , Xie Wenhao
Published: February 2021

Urbanization is taking place rapidly in developing countries. There are many problems of urbanization, and flood hazard is one of the serious problems. Flooding events and hydrologic process are complex in urbanized watershed. Current methods for urbanized watershed flood hazard risk assessment exist shortage. With the advance of observation technology and geographic information system technology, the multi-source spatial-temporal data have been collected increasingly. The data driven methods have provided a potential solution for the complex urbanized watershed flood hazard risk assessment. The paper has discussed the complexity of urbanized watershed flood hazard. The framework of observation based modeling of urbanized watershed flood hazard risk assessment has been given. Multi-source spatial-temporal information fusion approach for watershed flood hazard risk assessment has been discussed. A case of Hanyang urbanized watershed has been developed based on the multi-source information fusion method of local weighted linear combination.
Dynamic properties and seismic vulnerability of voltage transformer in substation
Authors: Zheng Shansuo , Wu Xingxia , Liu Xiaohang , Chen Dianxin
Published: February 2021

The evaluation of the seismic stability of electrical equipment is very important in substation. In this paper, the influence of support on seismic response and vulnerability of voltage transformer is studied., First, the support-voltage transformer finite element models(FEM) is established by Abaqus. Natural frequency, dynamic amplification factor of support-voltage transformer with different PGA are investigated. Afterwards, the seismic response parameters obtained by FEM simulation are applied to the vulnerability analysis of voltage transformers. Finally, the vulnerability result indicated that support height and ceramic material have significant effects on the probability of equipment failure.
Control of Harmful Effects in Blasting Demolition of Multi-span Aqueduct
Authors: Zhang Zhixiong , Yang Haiwei , Ye Xueyun , Hung Haidong , Lan Shengning
Published: February 2021

Taking the demolition blasting of complex structure of continuous multi-span aqueduct as the research object and combining with the importance analysis of safety factors in safety evaluation, the blasting scheme, reliability of electric blasting network, pretreatment quality, protection of buildings around the blasting area and safety protection are emphatically studied. The numerical model of aqueduct is established by LS-DYNA. Through the simulation analysis of the whole process of aqueduct blasting demolition and collapse, the blasting breakpoint and the design of pretreatment notch are reasonably determined. Carry out the equivalent electric blasting network test and field blasting test to check the reliability of the blasting network and determine the single hole charge. By the analysis and verification of safety parameters such as blasting shock wave, collapse vibration and safety distance, the active protective measures are taken to protect the important structures and public facilities within the blasting area. The blasting effect and monitoring data show that the safety technical measures can effectively control the safety risk of aqueduct blasting demolition.
The Environmental Capacity of Hun River, Liaoning Province, China
Authors: Li Xinghua , Du Liangang , Lv Xubo , Liu Yunlong , Huang Guoxian , Lei Kun , Sun Mingdong
Published: February 2021

Based on the environmental functional area allocation, point and non-point sources, hydrology and water quality data of Hun River, SWAT model is built and used to calculate the hydrological, water quality and environmental capacity processes in the river channel. The results showed: (1) When the upstream water quality concentration was limited to the grade III of the national surface water quality standard, the environmental capacity of total phosphorus (TP) in Hun River is about 582.01 t/a. (2) According to the results of water environmental capacity in different water periods, the environmental capacity of Hun River is seriously overloaded in the flood season, although annual value is satisfied the standard. For the strong driving effect on the pollutants transport in the river by the intense rainfall in flood season, the concentration in flood season exceeds the water quality standard of grade III. (3) To strengthen the environmental management of Hun River, it is necessary to monitor non-point sources in the cultivated land, standardize the fertilization measures, and improve the rural sewage pipe networks and related facilities.
Construction stability analysis of large section highway tunnel portal section based on numerical analysis
Authors: Wang Fuhua , Li Jun , Ding Libo , Wang Yetao , Song Zhanping
Published: February 2021

the entrance portal of No.8 tunnel of F3 bid section of E60 highway in Georgia is shallow buried and under unsymmetrical pressure, which leads to high risk and difficulty in tunnel construction. Tunnel 8 is designed based on ADECO-RS (analysis of controlled deformation in rock and soil). In order to understand the stability characteristics of tunnel portal in the whole section construction process and determine reasonable and feasible engineering countermeasures, the numerical simulation analysis of tunnel construction process is carried out. We not only studied the relationship between the stability of the slope at the entrance and the stability of the whole tunnel body under the actual stratum conditions, but also studied the mechanical and deformation characteristics of the surrounding rock and supporting structure of the tunnel.The numerical analysis results show that the stability characteristics of the portal slope directly affect the overall stability of the tunnel portal section; due to the disturbance of tunnel excavation, a large range of plastic zone appears at the interface of rock and soil at the portal section, resulting in large settlement deformation of vault. The collapse and deformation of the upper soil layer with poor engineering properties will cause excessive additional load on the supporting structure of the tunnel.Therefore, advance support measures should be taken to control the excessive deformation of vault. At the same time, due to the influence of asymmetric pressure, the supporting structure of the shallow buried side and the deep buried side of the tunnel appears obvious asymmetric pressure state. It is suggested to strengthen the stiffness of the shallow buried side support structure and adopt the asymmetric support structure to ensure the safety of the support structure.
Comparative study between acoustic wave transmission method and low strain reflection method to detect the integrity of piles
Authors: Yang Wanli , Bian Li , Wang Hao , Hu Shaokai , Kong Dexiang , Zhao Jinping
Published: February 2021

More than 400 friction piles of a highway bridge in northern China were detected by both acoustic transmission method and low strain reflection method,while the integrity levels of the piles were judged different by the two methods, they were finally identified by means of drilling core-taking or drilling television. The misjudgment of the acoustic transmission method and the low strain reflection method are counted, and classified statistics were conducted according to the location and type of defects, while the reasons of misjudgment are analyzed. Some suggestions for the comprehensive application of the acoustic transmission method and the low strain reflection method are put forward, which can be for the reference of the testing technician.
On the activation strategy of villages and towns from the perspective of catalyst- Take Jingfu Town, Santai County, Mianyang City as an example
Authors: Li Yuanyuan , Ge Yifei , Tan Yuwen , Peng Xinhai , Huang Qi
Published: February 2021

With the continuous development of society, as a transitional level between rural and urban areas in urban system, towns are facing a series of problems such as ignoring ecological environment, unreasonable planning content and lack of public space. In this paper, from the perspective of "urban catalyst", taking Jingfu town of Santai County as the research object, the concept of catalyst is introduced by investigating the existing problems of the site and respecting the local natural and cultural environment. It has a certain reference value for the activation and development of urban and rural towns to integrate and update the site resources, select the appropriate space of catalyst to promote the activation of surrounding areas, and promote the sustainable renewal of small towns through the framework of catalyst space system.
Research on Credit Evaluation of Construction Market EntitiesBased on Conditional Random Field
Authors: Zhenyu Zou , Jingchun Feng , Zhecheng Huang , Ke Zhang , Lei Zou
Published: February 2021

This paper firstly judges the change of credit level of the credit subject from the dynamic perspective of "state-behavior". Then, according to the conditional random field theory, the data of credit behavior and credit status are taken as random variables in the conditional random field to construct multiple characteristic functions representing the relationship between the credit behavior and the credit status. And finally, the credit evaluation system based on the conditional random field is constructed. In summary, this paper constructs a credit evaluation framework of market entities from the credit evaluation system and conditional random field credit labeling, which can be used in the construction of market credit dynamic supervision for reference.
Overview of the application of digital construction in airport construction
Authors: Jia Zhiguo , Lv Jihong
Published: February 2021

Aiming at the current application status of digital construction in various industries in China, this paper analyzes the GIS and BIM technology used in the existing digital construction, and summarizes the application of GIS and BIM technology in the digital construction in the airport construction industry, which also analyzes the application value and development prospect of digital construction in the area of airport construction.
Influence of overloaded vehicles on pavement life based on WIM data
Authors: He Yulong , Li Jing , Xu Xiao , Li Ao , Liu Hua , Jiang Tianlin , Shi Kaixin
Published: February 2021

In this paper, the weight distribution characteristics of overloaded vehicles and the influence of overloaded vehicles on pavement service life are studied based on WIM data. Based on the vehicle weight data collected from weight in motion station, the vehicle weight distribution function of different axle type trucks and the weight overload ratio distribution function of different axle types are obtained by fitting. Equivalent single axle loads of the pavement under different weight limits are calculated based on the vehicle weight distribution function, and finally the pavement life growth factors under different weight limits are determined. The calculation results show that: the maximum overload ratio of two-axle vehicle can reach 340%; the number of six-axle overloaded vehicle accounts for more than 50% of the total number of overloaded vehicles, which is the largest proportion. Pavement life can be improved effectively by limiting load, and the road life growth factor shows a quadratic parabolic trend to increase with the decrease of load limit value. For two axle trucks with serious overload, the pavement life can be increased by more than 15 times with a strict load limit value.
Preparation of Nano-porous aerogels by supercritical drying
Authors: Zhili SUI , Zhaoguang LI , Fenghong ZHANG , Xiangyong ZHANG
Published: February 2021

Nano-porous silica aerogels are synthesized by two steps by the supercritical condition. By synthesized process, tetra-ethyoxysilane is used as raw material, isopropanol and H2O which is distilled after ion exchange was used as solvent, HCl and NH4OH are used as hydrolysis and condensation catalysts, glycerol is used as drying control chemical agent. Silica aerogels are obtained by supercritical drying condition after aging, surface modification and exchanging solvent. The effect of water, PH, temperature, and so on, are analysed at supercritical drying condition. The resulting aerogels are characterized by means of X-ray diffraction and scanning electron microscopy. It is found that the aerogels made by this method have high porosity, specific surface area and the structure is sponge with narrow particle and pore size distribution.
Application of digital construction whole process monitoring and management technology for airport asphalt pavement
Authors: Kong Fandong , Liu Kaidi , Cao Cheng , Du Xiaoyu , Jiao Huanjing
Published: February 2021

The construction and management of airport asphalt pavement project has the characteristics of large construction scale, high technology, many professionals involved, and high quality requirements. The traditional monitoring and management method that relies on manual on-site inspections and records is vulnerable to many factors such as environmental conditions and the ability of the implementer. It is difficult to ensure real-time monitoring of construction quality and data backtracking. With the rapid development of various advanced technologies such as global navigation satellite system(GNSS), geographic information system(GIS) and internet of things(IoT), digital construction monitoring and management technology for airport asphalt pavement has emerged as the times require. Digital construction technology is implemented through professional testing equipment, data collection, data integration, and system installation. It covers the entire construction process of airport asphalt pavement from the background management of the mixing plant, the transportation management of vehicles to the field management of paving and compaction. The technology monitors the construction quality, guarantees the construction progress, improves management efficiency, and saves costs, which has great social and economic benefits.
All-in-one Power Conversion System for a Smart Factory
Authors: Kim DongJin , Kwon WanSung , Kim YongSu , Park Jaehyo , Seo SangWon , Park JongWoo
Published: February 2021

This paper investigates the incorporation of a PV-ESS linked, all-in-one power conversion system (PCS) at a small factory, in an attempt to improve the factory’s resilience against the increase in load due to facility expansion. The aforementioned factory was installed with 210kWh PV and 550kWh ESS, both of which were simultaneously managed by 250kW hybrid power conversion system. This independent operation of the factory through the PCS was proven to be efficient and economical, because of the reduced power usage and the sale of surplus electricity.
Substation operation ticket system based on natural language analysis and intelligent reasoning
Authors: ming Chen , dekai Chen , yupeng Jiang
Published: February 2021

[Background/Reason] The operation ticket system is an important measure to ensure the safety of substation operation. At present, the issuance and review of substation operation tickets rely on manual operation knowledge and experience, and there are problems such as low work efficiency, lack of standardization, and human error. The risk of grid operation is reduced. [Method/Process] This paper proposes a substation operation ticket system based on natural language analysis and intelligent reasoning. It uses typical/standard operation tickets as the basic corpus and builds a natural language analysis model based on manual labeling to achieve compliance with the operation tickets. Sexual inspection, deduction and comparison of equipment status. Finally, combining the primary wiring diagram of the substation and the operation ticket to construct the equipment relationship knowledge map and the equipment operation knowledge map, use the Neo4j graph database for storage, and realize the intelligent drafting of operation tickets based on the graph search method. [Results/Conclusions] The research results have been implemented and applied in three substations in a certain area, verifying that the system has a high degree of intelligence and versatility, and can effectively solve the existing problems of standard invoicing and audit errors, and improve operation The work efficiency of personnel and the safety control level of power grid substation operation.
Tree Barrier Prediction of Power lines based on Tree Height Growth Model
Authors: Jinqiu Wu , Hanjun Liu , Jiakai Yang , Yuhao Chen
Published: February 2021

Aiming at the problem that the hidden trouble of tree barrier seriously threatens the safe operation of power lines, the typical tree species in the corridor of power lines in Guangdong area are investigated and studied. Firstly, a tree height growth prediction model based on Richard’s equation is established. The correlation deviation test results show that the model can accurately predict the tree height. The hidden trouble of tree barrier under line and the hidden trouble caused by wind deviation of wire are analyzed. Finally, the model for predicting the clearance distance from tree to power lines is established. By predicting the clearance distance between wire and tree, the functions of real-time detection of hidden trouble of tree barrier and risk assessment and prediction of tree barrier are realized. It avoids the flashover fault caused by the excessive growth of trees, and ensures the safe and stable operation of power lines.
Research on Market Mechanism and Scheme Design of Yunnan Demand Response
Authors: Ma Gaoquan , Zhang Fan , Ding Wenjiao , Yang Dongyuan , Huang Yifan , Gao Ciwei
Published: February 2021

In order to cope with the changes of participants, working mechanism and business model after the deregulation of power sales side under the new situation, and to improve the current situation of seasonal and periodic power shortage in Yunnan Province, the implementation scheme of Yunnan demand response is sorted out and its characteristics are analysed from the aspects of participation mode, implementation form and response type. Based on the lack of basis for the demand response subsidy price and the imperfect transaction mechanism in Yunnan demand response market mechanism construction, this paper proposes a price mechanism design scheme of charging seasonal peak electricity price for peak shaving demand response, collecting funds according to the grid electricity of power generation enterprises during valley filling period, and dynamically adjusting the price according to the change of supply side cost caused by demand response. Additionally, the trading mechanism of demand side response participating in day ahead market and real-time market is also proposed.
Local Autonomous Optimization based Virtual Power Plant Dispatch Strategy
Authors: Zhao Jianli , Zhang Shaodi , Gao Ciwei , Ma Sisi , Wei Siya , Zheng Hongjuan
Published: February 2021

The load of central air conditioning can be transferred or reduced through reasonable control and has become an effective alternative resource for the adjustable capacity of power grid. In the demand response mode, the central air-conditioning load can be aggregated to form a virtual power plant to participate in the unified grid dispatching operation. In this paper, the virtual energy storage model of the central air-conditioning system is built based on the integrated thermal inertia. The paper also proposed the internal coordination control mechanism based on multiple agents. Furthermore, the regulatory potential of the central air-conditioning system is evaluated from the perspectives of adjustable power and sustainable time according to the virtual energy storage characteristics. The virtual power generation unit is constructed by means of comprehensive coordinated control so as to realize the standardized unified modeling of central air conditioning system. Finally, This paper proposes the strategy of virtual generating unit dispatch based on local autonomous optimization and the operation strategy of virtual power plant participating in grid peak regulation. Through the strategy the distributed optimal control of power generation resources is realized in virtual power plant and the pressure on virtual power plant operators is released. This paper has guiding significance for virtual power plant to participate in the actual dispatching operation of power network.
Comprehensive evaluation method of micro-energy harvesters for power supply of outdoor wireless sensors
Authors: Guo Luyang , Wang Shouxiang , Chen Haiwen , Yang Aichao , Liang Bin
Published: February 2021

There have been many solar or wind micro-energy collection technologies for outdoor wireless sensors, but it is difficult to compare them horizontally and choose the appropriate scheme. To overcome this problem, this paper proposes a comprehensive evaluation method of micro-energy harvesters which includes an evaluation matrix composed of three types of indexes and the corresponding test method. After the evaluation matrix is obtained by testing, a CRITIC-based weight calculation method is used to get a comprehensive score. Finally, ten commonly used solar or wind micro-energy harvesters in five typical regions are compared horizontally by the proposed method. The results show that the evaluation method can comprehensively consider various factors, and harvesters with higher comprehensive scores tend to have more balanced performance in all aspects. Furthermore, in regions with rich wind resources, the wind and solar harvesters have complementary time-domain characteristics.
Research on Optimal Planning Method of Distribution Network Considering Emergency Power Supply Configuration and User Differentiated Reliability Requirements
Authors: Zhang Zhen , Li Congli , Li Junjie , Gao Mengke , Deng Jiaming , Li Peng , Wang Zixuan
Published: February 2021

Considering the configuration of emergency power supply in the distribution network and the differentiated reliability requirements of end users, the optimization planning model is proposed in this paper, which can harmonize economy and reliability. The model aims at the optimal total cost of the distribution network, considers the user’s differentiated reliability indicators, solves the results of the location and capacity of distributed power sources and emergency power configuration. Finally, the optimal solution is selected by the particle swarm algorithm into the program. Three scenarios are set on the IEEE-33 node system for simulation testing. The results show that this method can effectively meet the consequence.
Research on frequency modulation of DFIG wind turbines auxiliary power grid based on improved frequency control
Authors: Zhang Hongpeng , Tian Zengyao , Li Dan , Wei Jingxiao , Liu Siqi , Ye Peng
Published: February 2021

With a large number of DFIG wind turbines connected to the power grid, in order to improve the frequency fluctuation caused by its decoupling, this paper first analyses the current situation of DFIG wind turbines participating in the primary frequency modulation of power grid, and establishes the corresponding model based on the above analysis. According to the commonly used inertial control methods, a frequency modulation method for auxiliary power grid of DFIG wind turbines based on improved frequency control strategy is proposed. Through the simulation of actual power grid model, the grid frequency fluctuation has been effectively alleviated after adding frequency control link to DFIG wind turbines, and it is concluded that the higher the wind power penetration, the more significant the frequency improvement effect.
Unit Commitment with Tunable Frequency Response from Wind Turbine Generators
Authors: Liu Juelin , Yu Juan , Rui Song , Huang Junkai , Xuebin Wang , Li Wenyuan
Published: February 2021

Based on the natural inertia on the rotors, wind turbine generators can provide both inertia response and primary frequency response to support the system frequency stability. In this paper, by considering the coordinated optimization of frequency response, a unit commitment with tunable frequency response from wind turbine generators is proposed. The relationship between inertia response and primary frequency response is analyzed. A frequency response correlation constraint is proposed to eliminate the second frequency nadir. Considering the system frequency stability constraints and the feasible region of frequency response provided by wind turbine generators, a security-constrained unit commitment model with tunable frequency response is established. According to the actual operation mode of the power system, a bi-level algorithm is adopted to calculate the frequency response parameters of wind turbine generators. The simulation result of the GB 2030 system demonstrates that the proposed method can reduce operating costs while ensuring system stability.
An Operation and Maintenance Training Platform for Distribution Terminal Unit
Authors: Pan Zhiyuan , Li Hongwei , Wang Jing , Peng Ganrong , Li Guanghong
Published: February 2021

Distribution terminal unit is an important part of distribution automation. The application and maintenance of distribution terminal unit is directly related to the operation effect of distribution automation. In order to improve the technical level of power company maintenance personnel, the distribution terminal unit operation and maintenance training platform is designed. It is also beneficial to understand the principle of distribution terminal unit, the action process of distribution automation, and master the daily operation and maintenance operation of distribution terminal unit. According to the actual faults in the distribution automation, the platform realizes the primary fault simulation of the distribution network and the secondary fault simulation of the distribution terminal unit. Then the maintenance personnel will carry out operation and maintenance operation to remove the fault. Its application improves the level of operation and maintenance operators.
Power Transformer Condition Assessment Method based on Improved Rough Fuzzy K-means Clustering
Authors: Li Chunpeng , Hu Xinyuan , Guan Guofei , Li Zhongwen , Luan Qiqi , Jiang Feng
Published: February 2021

As an important equipment of power transmission and transformation, power transformer plays a direct role on the reliability of power supply. Considering the low proportion of power transformer fault data and the overlap boundary with normal data, an imbalance measurement of cluster size is introduced and a power transformer state assessment based on rough fuzzy k-means clustering is proposed. The developed method can not only judge the type of fault that has occurred, but also predict the possible future faults of power transformers. The effectiveness of the designed method is verified by experimental comparative analysis.
Research on transformer condition evaluation technology based on vibration signal analysis
Authors: Hao Ma , Chuang Yao , Minghui Duan , Jufang Wei , Xin Zhang , Cong Zhao
Published: February 2021

In order to analyze and judge the looseness defects of transformer core and winding, the causes and characteristics of core and winding vibration were analyzed theoretically. It could be seen that the resonance frequency and frequency spectrum distribution of vibration signals at different measuring points were not the same.The vibration signals of different measuring points of the transformer shell under the conditions of normal core and winding looseness and different degrees of looseness were tested experimentally. Then the method for judging the looseness defect of core and winding based on the content of fundamental frequency signal was proposed, which had advantage in effectiveness and convenience. Finally, the further research direction was pointed out to promote actual using.
A collaborative planning method of distribution network including EV charging piles and Distributed Generations
Authors: Yang Haiyue , Liu Dong , Yu Lu , Liu Eryong , Mei Xiaohui , Wang Shouxiang
Published: February 2021

With the growing penetration rate of distributed generations (DGs) and large number of unordered charging electric vehicles (EVs), the distribution network (DN) is facing more challenges than before. Therefore, the DN planning integrated of EVs and DGs is the primely problem. Firstly, an traffic network model and a distributed power supply output model are established to simulate the actual traffic network flow distribution through the principle of user equilibrium flow distribution. Secondly, an improved adaptive free search algorithm is proposed to coordinate site selection planning of EV charging pile and DG considering the factors of economy and users’ satisfaction of charging. Finally, taking the modified IEEE 33-node distribution network as an example, the proposed model and algorithm are simulated and verified. The simulation results show that the proposed model and programming method are feasible and effective.
Fault recovery strategy of distribution networks with multiple EHs for reliability improvement
Authors: Jin Qiang , Ma Weijing , Hu Ping , Qi Xiaoguang , Zhang Xianliang , Pan Yongchao , Zhang Lu
Published: February 2021

It has become a trend that user-side electricity/heat/gas energy supplies and loads are connected to the distribution network with energy hubs (EHs). The integrations of EHs bring new opportunities for the improvement of power supply reliability of distribution networks. For the distribution network with multiple EHs, a fault recovery strategy for the improvement of power supply reliability is proposed in this paper. Combining the models of EHs and radial distribution network, the typical structure of distribution network with multiple EHs is analyzed. Considering the scope of the fault and EH optimal dispatching, a failure recovery strategy for reliability improvement of distribution network with multiple EHs is proposed. With the objective of minimum power outage losses and operating costs, an optimal scheduling model for multiple EHs island operation is established. The analysis of the calculation example shows that the grid-connected operation of EH can improve the reliability of distribution network, and the optimal dispatch of the EH can effectively reduce the loss of power outage during the failure.
Optimal Restoration Strategy Based on Resilience Improvement for Power Transmission Systems Under Extreme Weather Events
Authors: Yu Z.Y. , Li Z.P. , Qian T. , Huang K.C. , Chen X.Y. , Tang W.H.
Published: February 2021

In the past few years, extreme weather events have threatened operations of power systems. The improvement of resilience for power system becomes crucial. This paper proposes an optimal restoration strategy, considering the resilience index of power transmission systems in restoration processes. Firstly, a typhoon is taken as an example to establish an extreme weather event impact model to obtain the failure probability of lines. Then Monte Carlo method is used to generate fault sets. For each restoration time point, the optimal restoration model is used to acquire the maximum recovery loads. The resilience index of system can be obtained by the resilience assessment methodology during restoration. Finally, the proposed strategy is compared with distance-based strategy in IEEE 6-bus system, which demonstrates the superiority of the proposed strategy.
Incentive-based Demand Response for a Virtual Power Plant
Authors: Li Yingyi , Luo Zhe , Liu Lifeng , Sun Ke , Yang Xuan , Huang Tian’en
Published: February 2021

With the development of Energy Internet, the virtual power plant (VPP) has been regarded as a creative and attractive form to realize the integration of different energy resources. The VPP could make advantages of demand-side participation and distributed energy resources (DERs) to eliminate the peak loads and thus to maintain the stability of power grid. Here, an incentive-based demand response (DR) scheme is designed to model the energy transactions in the VPP internal market. This scheme considers different attitudes of different kinds of consumers according to their DR bid offers. Especially, we also introduce the dissatisfaction function to model the impact of load reductions on the enthusiasm of consumers. With the objective to minimize VPP operation costs, the proposed scheme is formulated as an optimization problem with guaranteeing the interests of consumers. The experimental results show that the proposed incentive-based DR scheme could encourage consumers to reduce more load demands by offering corresponding incentive prices, which helps to decrease the total operation cost of the VPP and also improve the profits of consumers.
Forecast and Analysis of Regional Energy Demand Based on Grey Linear Regression Forecast Model
Authors: Zhang Mingli , Li Zhongwei , Song Kun , Guan Duojiao , Zhang Na , Ye Peng , Li Dadong , Man Linkun , Xu Xilin
Published: February 2021

Energy is an important material basis for guaranteeing and promoting economic growth and social development. In order to predict the future energy demand for regional energy in Liaoning Province, this paper uses the gray forecast model to make reasonable predictions on regional energy in Liaoning. This paper first establishes a gray prediction model, analyzes the applicable environment and conditions of the gray prediction model, and secondly uses the gray prediction model to predict the energy of Liaoning Province from 2010 to 2019, and compares it with the actual data and elastic coefficient method. It shows that the prediction accuracy based on the gray prediction model is significantly higher than that of the traditional elasticity coefficient prediction method, which proves the scientificity and effectiveness of the model for regional energy demand prediction. Finally, on this basis, this paper uses the grey prediction model to analyze the energy of Liaoning Province from 2020 to 2029. The method and data can provide reliable data basis for the planning of Liaoning power grid and the evolution of the future power grid.
Research on agile generation method of electromagnetic transient simulation model based on multiple information sources
Authors: Li Tao , Huang Miao , Liu Jun , Jiang Zheng , Wen Xu
Published: February 2021

Based on electromechanical transient simulation data, an electromagnetic transient simulation model can be quickly generated through a computer program. However, electromechanical transient data are not sufficient to describe completely the corresponding electromagnetic transient simulation model. In view of this, the paper proposes an electromagnetic transient simulation model generation method that integrates multiple information sources. First, the data characteristics of electromechanical transient simulation software PSD-BPA and electromagnetic transient simulation software PSCAD/EMTDC are introduced. Then, considering the difference between electromechanical transient and electromagnetic transient model data, a method to quickly generate PSCAD/EMTDC simulation data is established. This method is based on the electromechanical transient simulation data, and takes into account those information which is not available in the electromechanical transient data but needed in the electromagnetic transient in the conversion process, so that the converted model is more detailed and accurate. Finally, this method is used to model and analyse an actual fault. The simulation results show that the method proposed in the paper is effective and credible.