bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Research on the Domain and Potential for Further Electrification of Rural Domestic Energy Consumption
Authors: Feng Kaihui , Li Qionghui , Huang Bibin , Yan Hu 
Published: March 2020

Abstract
As energy production and the consumption revolution continues to deepen in the 21st century, the world is entering a new phase of electrification. On the supply side, there are now more and more clean energy sources of electricity such as wind and solar that are being developed and utilized. On the consumption side, electrical energy is continuing to replace fossil fuels. As electric engines, electric cooking and electric heating become more common, electricity will increasingly displace coal and oil. Currently, energy consumption levels are low in rural China, especially in the domestic sector, constraining rural-urban integration and development as well as improvement in the energy consumption of rural regions. Electrification is an effective way to make rural energy consumption cleaner and less carbon-intensive. It can significantly reduce pollution and emissions, thus improving the quality of life and the environment. The present paper discusses the main applications of electrification in rural energy consumption. As rural-urban integration continues to develop, rural energy consumption levels will gradually converge with urban energy consumption levels. The present paper proposes areas where there is potential to increase electrification in rural domestic energy consumption, providing a reference for improving rural domestic energy consumption, bearing significance for energy transformation and mitigation of rural environmental pollution.
Research on the Effect of Plant Boundary Conditions on Noise Attenuation in UHV Substations
Authors: Ni Yuan , Wang Yanzhao , Wang Meishun , Zhou Bing , Hu Jingzhu , Zhang Jiangong 
Published: March 2020

Abstract
Accurately analyzing the influence of the terrain environment of the plant boundary on noise transmission and attenuation can not only give guidance for the substation site selection and station layout optimization, but also provide theoretical basis for noise abatement after the substation has been put into operation. In this paper, by applying sound level meters to test the sound pressure of the main equipment in the substation and the noise around the plant boundary, the noise characteristics of main transformers and shunt reactors, as well as the noise distribution around the plant boundary were analyzed, thus concluding that the noise at the plant boundary is mostly derived from the main equipment within the substation. While taking the layout of the Zhebei UHV Substation as an example, this paper chose the SoundPLAN software to simulate and calculate the noise attenuation law under seven terrain conditions outside the plant boundary, and finally such a proposition as the low-lying terrain and the raised hilly terrain can best interrupt the noise transmission was made. The conclusions of this paper can provide a theoretical reference for site selection of new substations and optimizing the terrain structures of substations in operation.
Research on High Efficiency Air Cooling Method of High Power Density Power Electronic Equipment
Authors: Liang Jinhua , Xu Haiping , Gong Chen , Yuan Zengquan , Zhang Zuzhi 
Published: March 2020

Abstract
High power density is a trend of power electronic equipment development, but high power density will inevitably lead to high power consumption per unit volume. Due to the limitation of environmental conditions, some equipment can only use air cooling method, but the conventional way of air-cooled cooling is difficult to meet the requirements of reasonable temperature rise. Therefore, a new type of thermal resistance model is put forward, by using the good isothermal performance and high thermal conductivity of the heat pipe, the surface embedded composite heat dissipation substrate is made, which greatly reduces the diffusion thermal resistance, at the same time, and uses a new type of thermal conductivity material to reduce the contact thermal resistance. In order to improve the efficiency of thermal design, several mathematical inequalities are established, and the calculation of thermal resistance is transformed into a single objective optimization problem with multiple constraints. MATLAB is used to solve many discrete solutions, and then the finite element simulation software is used to further optimize. Finally, the temperature rise test of the prototype shows that the heat dissipation efficiency is increased by three times.
Power Saving Management Based on Simulation of Domestic Air Conditioning Operation
Authors: Liu Fang , Zhou Hui 
Published: March 2020

Abstract
With the continuous increase of building area and the improvement of people’s economic level, the penetration rate of air conditioners in China has continued to rise. Scientific residents’ air-conditioning behavior not only helps users save power, but also has important significance for rational planning on the power demand side, smooth operation of the power grid, and alleviating the contradiction between power supply and demand. This paper combines the thermal comfort theory of the human body with the thermal balance theory of the room, and establishes the thermal balance equation and thermodynamic model of the air-conditioned room. Different air-conditioning behavior models are designed for simulation. Through simulation, according to the simulation results, this paper puts forward air conditioning behavior recommendations for residents with different living habits in different cities in the north and south.
Multi-state household appliance identification based on neural network
Authors: Zhang Ying , Xu Jiali , Du Zehua , Dong Xifeng 
Published: March 2020

Abstract
In the current non-intrusive load monitoring process, the states switching of some multi-state appliances is difficult to be correctly identified by the switch event detection method, and the energy consumption statistics due to poor multi-state identification of the electrical appliances are not accurate. This paper proposes a multi-state household appliance load identification method based on convolutional neural network and clustering model. First, a convolutional neural network is used to construct an appliance type identification model. Then, a multi-state identification model is established to identify the state of different multi-state appliances. The experimental results show that the proposed method achieves multi-state identification of electrical appliances and has good engineering and practical value.
The calculation method of optimized AC choppers capacity in islanded MMC-HVDC system
Authors: Wang Shanshan , Qin Shanmeng , Zhao Bing , Sun Yuanyuan , Yin Rui , Zhao Yuetong , Yang Panbo 
Published: March 2020

Abstract
In order to ensure the safety of renewable energy generation integration system through islanded MMC-HVDC, the AC choppers with the same capacity as sending end converter station are equipped in current projects. However, considering the actual operation needs, it is not necessary to equip so many AC choppers. The optimal capacity of the AC choppers can be calculated according to the most serious fault. The calculated capacity can meet two requirements. One is the renewable energy generation units just start to cut off when the DC voltage reaches the overvoltage limit value. Another one is to minimize the cost and floor area of the AC choppers. It can ensure that the converter station devices is not be damaged in the condition of lowest economic cost. A three-terminal and a four-terminal renewable energy generation integration system through islanded MMC-HVDC are built in PSCAD, which verifies the correctness of the theoretical analysis.
Fault location method for neutral ungrounded system based on C- type travelling wave method
Authors: Fan Haiyan , Qi Jincheng , Sun Zhilian , Zhao Fayun , Guo Ningming 
Published: March 2020

Abstract
In China, the 10kV distribution network operates with neutral ungrounded. Due to the influence of high transition impedance and branches, the problem of fault location has not been effectively solved. The characteristics of C-type travelling wave method at neutral ungrounded system are analyzed in this paper. Multi-point fault location method based on C-type travelling wave method is proposed. By actively injecting high-voltage pulses into the circuit and using multiple measuring devices to detect the reflected wave of the fault point, the effect of high-impedance- grounded and branch points on the reflected wave of the fault point is effectively reduced, and the success rates of reflected wave detection of the fault point are improved. The validity of the method is verified by simulation.
A Fast Energy Equalization Control Strategy of Flywheel Array System Based on Fuzzy Power Distribution Control
Authors: Ren Jingpan , Ma Hongwei 
Published: March 2020

Abstract
Flywheel array is a kind of energy storage device with good performance, but there is still no suitable power distribution strategy which hinders its development. This paper proposed a flywheel array energy distribution control strategy based on fuzzy control. This control strategy takes the balance of residual energy among the flywheel units as the target, and by establishing appropriate fuzzy control rules to allocate the power required by the array. This method solved the problem of residual energy imbalance among each unit in flywheel array and improved the reliability of the flywheel array. Simulation results based on Matlab/Simulink verify the effectiveness of the proposed strategy.
Investment Effectively and Benefit Evaluation of Transmission Technology Project Based on DEA
Authors: Qi Xia , Wang Mianbin , An Lei , Geng PengYun , Wang Jianjun 
Published: March 2020

Abstract
With the advancement of power reform, the profit model of the power grid enterprise will undergo major changes. It is requiring the grid enterprise to control its own costs more precise. As a routine maintenance work to ensure the safe and stable transportation of electric energy, the grid technical transformation project has a great impact on the grid operation cost. Due to the many factors involved in the project, it is generally difficult to estimate the investment efficiency and often based on experience. It is difficult for the power grid enterprise to make a scientific and objective assessment of the investment efficiency of the technical transformation project. Firstly, this paper constructs the evaluation index system of investment efficiency of the grid technical transformation project from input-output perspective, and then the DEA method is chosen. Through the analysis of a case study, it proves the effectiveness of the proposed index system and method, and some advices are also given.
Analysis of Electromagnetic Interference in Shielded Cables by Ground Potential Difference in Substation
Authors: Fu Longhai 
Published: March 2020

Abstract
At this stage, with the continuous improvement of the substation voltage level and the use of related intelligent equipment, the electromagnetic environment is gradually complicated, which seriously threatens the safety and reliability of the operation of the high-voltage transmission system.In view of this, based on the analysis of the theory of substation ground potential difference, this paper studies the specific causes of electromagnetic interference of shielded cables in substation ground potential difference, and then proposes the main measures to prevent the rise of substation ground potential, and the anti-interference ability of shielded cables. It is of great practical significance to improve the anti-jamming ability of shielded cable.
Summary of calculation methods of PMSM iron loss based on finite element analysis
Authors: Zhou Jincheng , Hu Bowen 
Published: March 2020

Abstract
Since the birth of the motor, the accurate calculation of the iron loss of the motor has always been a big problem in the field of motor design.Too many factors affect the change of the iron loss of the motor, which is the main reason why it is difficult to accurately calculate the iron loss of the motor.The traditional magnetic circuit method and the finite element method are the two main ways to calculate the iron loss at present. In this paper, various iron loss calculation models in the finite element method are summarized and introduced,and the advantages of each model are compared.
Optimization of scanning path under ion beam cleaning process based on thermal effect
Authors: Zhang Shouzhen , Yuan Zheng , Pan Xiaobing , Su Hongchun , Wang Zhibin , Zhang Wei , Gong Lihong 
Published: March 2020

Abstract
Ion beam figuring (IBF) is an advanced machining technology for high precise optical component. For brittle materials with high thermal expansion coefficient such as KDP crystal, thermal effect is an intractable problem due to the accumulative heat introduced by incident ions on optical surface. Asymmetrical heating induces rapid changes of thermal stress and once the thermal stress exceeds the mechanical strength, the component may crack or break. In this paper, the number of scanning rows was factorized to various combinations with times of scanning and the number of moving rows. Temperature field and thermal stress of each combination were simulated using finite element analysis software ANSYS. Comparing with the results, the much better combination was found. With optimized scanning path, peak of thermal stress is lower than that of traditional scanning path. Especially, peak of tensile stress on X-distance and Y-distance were reduced obviously. At last, a law for optimization was established: when times of scanning and the number of scanning rows are equal or approximately equal, the thermal stress appears lower.
Research on thermal effect of KDP crystal under ion beam cleaning
Authors: Yuan Zheng , Zhang Shouzhen , Pan Xiaobing , Wang Zhibin , Su Hongchun , Zhang Wei , Gan Jianfeng 
Published: March 2020

Abstract
KDP crystal is difficult to fabricate for high precision. because it is brittle soft and with high heat expansion. Magnetorheological finishing (MRF) has been used to machine KDP for high precision. However, iron powders are easily embedded into KDP surface. Ion beam figuring (IBF) can clean iron powders embedded and enhanced laser-induced damage resistance. However, the thermal effect introduced by incident ions is a headachy problem. Temperature fields have been calculated by finite element simulation and measured by experiments. Thereof temperature fields of optical component bombarded by low energy ion beam were estimated and this estimate method is proved to be correct and feasible by comparing results of finite element simulation and experiments. And then, thermal stress of KDP under ion beam irradiation was calculated and discussed. Distributions of temperature and stress on KDP surface are accordant with beam current distribution. Temperature and stress rise quickly under ion beam irradiation, while decreases rapidly without ion beam irradiation. Peaks of temperature and thermal stress tend to periodicity. The period corresponds the period of ion beam moving spasmodically and fleetly in Y direction. Tensile stresses are not visible at X/Y/Z direction, but compressive stress at X direction is larger obviously than that of Y/Z direction.
Matching Method of Lunar Remote Sensing Image Based on Laplacian
Authors: Zhan Liang , Ma Jun , Sang xuejia , Luo Dan , Chen Xuehua 
Published: March 2020

Abstract
In recent years, there is an emerging interest in the exploration of the lunar surface. We can use many images of the lunar with different resolutions sent by more and more satellites that launched to the Moon. However, research on the lunar image matching still faces various difficulties. Significantly differing from the complex physical structure of the Earth’s surface, the lunar surface is mainly craters, ridges and mountains, and its simple physical structure directly leads to the difficulty of extracting the same name points; satellite sensors are easily influenced by multiple factors while imaging, such as the shooting angle of the forward-looking and backward-looking linear array, the sun’s angle of incidence, which is likely to cause some differences in the brightness of the images, and it makes the image matching choose the appropriate image enhancement method. In this paper, taking Chang’e II CCD lunar image as an example, firstly we propose a method of extracting the same-name point of lunar images based on Laplacian and image grayscale matching, and compare it with the commonly used SIFT + RANSAC algorithm, the accuracy rate and processing speed rate increases by 4.55% and 58.3% respectively, which verifies the scientificity and rationality of this method. Our work provides a new idea for the study of lunar image matching technology and lays foundation for the image-based lunar surface research and development.
Study on Influence Factors of Series-Parallel Compensation Device Voltage Control
Authors: Zhang Zhanjun , Dong Ji , Dong Yao , Wang jianfeng , Yang Huaijian 
Published: March 2020

Abstract
Aiming at the power quality problem of voltage sag in distribution network, the control factors and effects of dynamic voltage restorer (DVR) and distribution static synchronous compensator (DSTATCOM) are studied to flexibly configure DFACTS devices and improve the voltage quality of distribution network. Firstly, the basic principle and compensation strategy of DVR and DSTATCOM are elaborated. Then, the performance influencing factors of two compensation devices are deduced. The influence of voltage sag amplitude, system capacity and load capacity is discussed. It is concluded that the voltage compensation performance of DVR is directly related to load capacity and voltage sag amplitude, while DSTATCOM is directly related to system capacity and voltage sag amplitude. Finally, the effectiveness of the proposed method is validated by comparing the control effects of the two compensation devices on voltage sag under different voltage sag magnitude, system capacity and load capacity, which provides a theoretical basis for the reasonable access of DVR and DSTATCOM in distribution network.
Gas sensor fault diagnosis based on Convolutional Neural Network
Authors: Sun Yongyi , Liu Yangyang , Ji Fang , Li Gang , Ma Yanjun , Li Jin , Yang Lixin , Zhang Hongquan 
Published: March 2020

Abstract
Gas sensor often fails due to the influence of temperature, humidity, lighting, dust and toxic gases, and causes unreliable phenomena. Therefore, the fault diagnosis of gas sensors is considered as a weak link. Feature extraction and classification play an important role in gas sensor fault diagnosis. However, there are many problems in traditional feature extraction methods. For example, 1) requirements for expert experience, 2) sensitivity of changes in mechanical systems, 3) limitations of new feature extraction. Therefore, it is meaningful and attractive to develop a method that can discover and learn fault-sensitive features of gas sensors from the original data and classify them effectively according to the sensitive features. Convolutional neural network(CNN) has been widely applied in image analysis and voice recording, and has achieved great success. However, gas sensor fault diagnosis is rarely applied. This paper focuses on using CNN to learn fault features from data, extract features automatically, and then classify them effectively. Experiments show that the CNN method provides a effective solution for gas sensor fault diagnosis.