bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-invasive Detection of Ketum Users through Objective Analysis of EEG Signals
Authors: Nawayi Siti Habibah , Vijean Vikneswaran , Salleh Ahmad Faizal , Rashid Abd Rusdi , Planiappan Rajkumar , Lim C C , Fook CY , Awang Ardeenawatie Saidatul
Published: November 2021

Ketum leaves are traditionaly used for treatment of backpain and reduce fatigue. However, in recent years people use ketum leaves to substitute traditional drugs as they can easily be obtained at a low cost. Currently, a robust test for ketum detection is not available. Although ketum usage detection via test strip is available, however, the method is possible to be polluted by other substances and can be manipulated. Brain signals have unique characteristics and are well-known as a robust method for recognition and disease detection. Thus, this study has been done to distinguish between ketum users and non-users via brain signal characteristics. Eight participants were chosen, four of whom are heavy ketum users and four non-users with no health issues. Data were collected using the eegoSports device in relaxed state. In pre-processing, notch filter and Independent Component Analysis (ICA) were used to remove artifacts. Wavelet Packet Transform (WPT) was used to reduce the large data dimension and extract features from the brain signal. To select the most significant features, T-Test was used. Support Vector Machine (SVM), K-Nearest Neighbour, and Ensemble classifier were used to categorize the input data into ketum users and non-users. Ensemble classifier was found to be able to predict the testing instances with 100% accuracy for open and closed eyes task with Teager energy and energy to standard deviation ratio as the features.
Electromyography Signal Pattern Recognition for Movement of Shoulder
Authors: Norali A N , Anas M N , Zakaria Z , Asymawi M , Abu Bakar A H , Chong Y F
Published: November 2021

Pectoralis major and deltoid are two muscles that are associated with the movement of the shoulder. Electromyography (EMG) signal acquired from these two muscles can be used to classify the movement of the shoulder based on pattern recognition. In this paper, an experiment for EMG data collection involves eight healthy male subjects who perform four shoulder movements which are flexion, extension, internal rotation and external rotation. Feature extraction of EMG data is done using root mean square (RMS), variance (VAR) and zero crossing (ZC). For pattern recognition, the classifiers that are used are Support Vector Machine (SVM), K-Nearest Neighbour (KNN), Linear Discriminant Analysis (LDA) and Quadratic Discriminant Analysis (QDA). Classification results shows highest accuracy on ZC feature using an SVM classifier with cubic kernel. The study on shoulder movement using EMG of pectoralis and deltoid muscles could be extended on arm amputees based on hypothesis that the EMG signal could be utilized for control of robotic prosthetic arm.
Segmentation of Tumour Region on Breast Histopathology Images for Assessment of Glandular Formation in Breast Cancer Grading
Authors: Nor Rahim P A S , Mustafa N , Yazid H , Xiao Jian T , Daud S , Rahman K S A
Published: November 2021

Breast cancer is the most silent killer among cancers nowadays. NHG system is widely accepted worldwide as a gold standard in providing the overall grade to breast cancer. One of the breast cancer features used in the NHG system is tubule formation. Assessment of tubule formation requires pathologist to identify tumour regions. However, colour variation on breast histopathology could influence tumour regions detection on breast histopathology images. Manual identification of tumour regions using microscope may also vary between pathologists. Thus, automatic segmentation is crucial to segment tumour regions. In this study, a simple approach of segmentation was proposed to segment tumour region on breast histopathology images. The proposed segmentation involved three stages: pre-processing, segmentation and post-processing. The proposed approach using GHE and median filter in the pre-processing stage; Otsu thresholding in the segmentation stage and; morphological operation and pixel removal in the post-processing stage was found able to segment the tumour region with average segmentation accuracy of 90.4 %.
Medical imaging and analysis of dedifferentiated chondrosarcoma using CT, MRI and ultrasound
Authors: Rasheed M E H , Youseffi M , Jamil M M A , Ibrahim T N T , Parisi L
Published: November 2021

Chondrosarcoma (CS) is a type of bone cancer that arises from the malignant transformation of chondrocytes and spreads metastatically to the surrounding bone tissue. CSs tend to grow and spread slowly, dedifferentiating into high-grade tumours; however, the cancer may grow rapidly too. What causes chondrosarcoma is not known, though it may arise from a benign tumour or bone conditions. Typically, CS tumours originate from the bones of the axial skeleton, but they may also occur in other parts of the body. CS patients usually experience aching pain around the tumour, especially at night or during physical activity, and it slowly deteriorates. Medical imaging tests play an important role in the diagnosis of CS; nevertheless, a tissue biopsy is required to confirm its diagnosis. The role of medical imaging is also vital in guiding and monitoring treatments. Surgical resection of the tumour is commonly the primary treatment for most types of CS due to its resistance to chemotherapy and radiation therapy. This work presents the case of a deceased middle-aged male subject with dedifferentiated CS of the right chest wall, including analysis of medical images involving both ionising (computed tomography) and non-ionising techniques (ultrasound and magnetic resonance imaging), in addition to treatments the subject received, along with their outcomes. Five generations of the subject’s family were investigated in detail and the subject was found the only cancer case in his family. Furthermore, the subject did not benefit from any treatments he underwent, and he died within two years from the diagnosis.
Study of Electrostatic Field Responses of Locally Marketed Face Masks in the Philippines
Authors: Esmeria J , Fernandez P N , Oyong G G
Published: November 2021

The face mask is the first line of defense against infectious particulates and droplets that may cause illness. Currently in the Philippines, the wearing of face mask is compulsory whenever citizens leave their residences as mandated by the government to mitigate the spread of COVID-19. The wearing of face masks has become a new normal among Filipinos. This created market opportunities for different types which became commonly and immediately available for purchase. This study aimed to differentiate the effectiveness of locally available face masks in terms of electrostatic filtration capability. Twelve different types of face masks grouped into five categories – surgical, fabric, N95 variants, foam type, and novelty type – were evaluated. Electrostatic fields were measured from each face mask including pore sizes via scanning electron microscopy. Moreover, by utilizing the estimated charge and mass of the SARS-CoV-2 virion, the transmission rate was simulated using COMSOL Multiphysics®. It was observed that face masks with negatively charged materials combined with small pore sizes afforded less particle transmission. The results of this study are of timely significance in potentially laying out public awareness in the selection and utilization of face masks that can provide foremost shielding against viral transmission.
A Numerical Study on Indoor Air Quality (IAQ) Designs for Hospital Waiting Room in The Context of COVID-19 For Hot and Warm Humidity Climate
Authors: Rahman Y M N , Razlan Z M , Nazrin Y M , Razali N A A , Izham M I , Ibrahim I , Desa H , Zulkepli N N , Azizan M A
Published: November 2021

COVID-19 is a virus originated from Corona Virus which can severe acute respiratory syndrome (SARS) symptoms such as chest pain, dry cough, fever, and difficulty breathing. The AC and ventilation system is not only important for the thermal comfort occupants but to ensure the room is safe and free from infectious virus. Thermal comfort is important measurement in indoor space which influenced by temperature, Relative Humidity (RH), airflow velocity and others. This research was executed and focused on lecture room in Bilik Persatuan 10, Universiti Malaysia Perlis (UniMAP) instead of real hospital waiting room. It comes with the room dimensions 11.87m (Length) × 5.17m (Width) × 2.93m (Height) for the numerical study. In addition, Computational Fluid Dynamics (CFD) analysis is used to investigate the air flow pattern and temperature distribution inside the room. By using software Ansys FLUENT 19, field experimental and simulation work can be compared which have 14.55% difference in temperature distribution. It is expected by increasing the air velocity of the AC inlet diffuser influence the pattern of airflow in the room, but average temperature remains same for all these conditions.
Comparing and Analysis of Test and Evaluation Methods for Connected Vehicle Communication Antenna System
Authors: Zhu Tong , Ji Guotian , Jiang Guokai , Ding Yifu , Feng Jiaxu , Wang Changyuan
Published: November 2021

With the development of Connected Vehicle, various of on-board applications and functions rely on stable, reliable and fast-response wireless connections furtherly, making it more urgent and widespread for vehicles to be equipped with relevant antenna systems such as positioning and communication. There are many types of vehicle antenna systems, together with a wide range of installation locations and a complex electronic environment which brings a huge challenges to the development of antenna manufacturers and the matching of automobile OEMs. In order to carry out the R&D, matching and testing of the vehicle antenna system better, various parties have proposed a multi-dimensional test and evaluation methods, but there is still a lack of horizontal evaluation between them. This paper analyses the requirements of automotive antenna system evaluation, sorts out and compares the technical paths of various common solutions, summarizes the characteristics and differences of various solutions, and provides a research foundation for further optimizing the vehicle-level antenna system test and evaluation program.
Current Status and Prospects of Gas Turbine Technology Application
Authors: Li Jiangpeng , Liu Ziti , Ye Ruoxuan
Published: November 2021

The gas turbine is widely used in various fields, including powering aircraft, ships, trains, and electrical generators. This paper reviews multiple researches about two usages of gas turbines, including power generation and propulsion in aerospace. To be specific, two types of gas turbines have been considered in the power generation section. The first one is the micro-scale turbine, and its working principle has been introduced in section 2.1.1. In addition, six diverse kinds of gas turbines, sorted by a different manufacturer, are introduced in 2.1.2, and it has been found out that, compared to its counterpart, EnerTwin is obviously more sustainable. At the same time, both of them generally cost the same. The second type of gas turbine is used in a combined cycle power plant (CCPP), a popular power station. The working principle of CCPP is introduced in 2.2.1, while several optimization methods are illustrated in 2.2.2, including solar thermal power methods and other novel methods. The result indicates that the most popular method of optimizing the combined cycle gas turbine is integrating an additional unit. One of those outstanding technics is the integrated solar-combined cycle, contributing to 64% of fuel saving with 2.8% of output reduction.
Research on small lightweight electromagnetic interference measurement system based on patrol unmanned aerial vehicle
Authors: Liu Pingyuan , Wu Nian , Yao Junwen , Ke Xianbin , Bie Shiguang , Liu Feng
Published: November 2021

Unmanned aerial vehicle (UAV) has been widely used in power system inspection. Most of the existing UAVs are equipped with visible and infrared cameras for fast full spectrum photography and fault monitoring of transmission lines. When the transmission line has defects such as aging, broken strand and serious corrosion, the traditional image recognition, infrared and other observation methods can not identify these defects well. In order to realize the rapid detection and judgment of broken strand, this paper analyzes the characteristics of electromagnetic interference of transmission line, and constructs the electromagnetic interference measurement system based on patrol UAV. The research results of this paper can realize the real-time detection and alarm of broken strand, and provide technical support for line inspection.
Development of the Line Protection Measurement and Control Device based on Domestic MCU
Authors: Zhao Chengxuan , Wang Yuantao , Ni Chuankun , Chen Hu , Xu Yunlong , Ma Wei , Su Yaxin
Published: November 2021

In this paper, the dual MCU hardware architecture of protection measurement and control device was presented by analyzing the current situation of domestic MCU and chip selection. The problems existing in ADC sampling accuracy and ADC integral non-linearity were studied. The design scheme of high-precision ADC acquisition system based on dual MCU architecture was proposed, which could meet the requirements of technical specifications by using oversampling and adaptive processing of sampling nonlinear area. In terms of reliability, the EMC performance of the device was promoted by the improvement of outlet and ADC acquisition circuit.
Transmission line condition assessment technology based on multi-source Parameter Fusion
Authors: Dai Wentao , Wang Minzhen , Guo Jiankai , Li Zheng , Qiao Dongliang , Shang Ziwen
Published: November 2021

Aiming at the shortcomings of current transmission line state evaluation, which refers to the isolation of scalars and the low accuracy of evaluation methods, a transmission line state evaluation technology based on multi-source parameter fusion is proposed. This paper collects and selects characteristic data such as line test inspection information, operation and maintenance records, and power grid operating parameters as indicator quantities. The membership function is used to express the distribution state of the index quantity, and the distribution state is used as the data to establish a comprehensive evaluation model of the line operation state based on the long- and short-term memory network. The data tag is used to train the deep network to establish the mapping relationship between index parameters and operation state. Experiments show that the evaluation accuracy of the proposed method is significantly higher than that of the traditional shallow method, which can provide theoretical guidance for the operation and maintenance of overhead transmission lines.
Complete characteristic curve processing method based on improved backpropagation neural network and Logarithmic curve projection
Authors: Liu Baonan , Zhou Jianzhong
Published: November 2021

The calculation of transient process is the basis of the design and construction of pumped storage power plant, which directly affects operation stability of pumped storage units. However, for satisfying the design of uniform and smooth flow in both directions, the complete characteristic curves of pumped turbine show a significant S feature, which brings difficulties to the interpolation calculation in the transient process as there are crossover and overlap phenomenon in pump and turbine working conditions. In this paper, a transformation method for complete characteristic curves based on logarithmic curve projection and improved backpropagation neural network is presented to solve the above problem. Furthermore, the feasibility and accuracy of the method are verified through the comparison of load rejection condition with on-site measurement, the results show that the proposed method overcomes the multi-value problem that exists in the original curve, in especial makes the small opening region well expressed. The simulation based on the transformed curve reaches a high similarity of transient process with the field test, both in the trend and extreme values, which provides great convenience for the calculation of transient process.
The Heat Transfer Coefficient Predictions in Engineering Applications
Authors: Wan Junchi
Published: November 2021

Most engineering applications have boundary layers; the convective transport of mass, momentum and heat normally occurs through a thin boundary layer close to the wall. It is essential to predict the boundary layer heat transfer phenomenon on the surface of various engineering machines through calculations. The experimental, analogy and numerical methods are the three main methods used to obtain convective heat transfer coefficient. The Reynolds analogy provides a useful method to estimate the heat transfer rate with known surface friction. In the Reynolds analogy, the heat transfer coefficient is independent of the temperature ratio between the wall and the fluid. Other methods also ignore the effect of the temperature ratio. This paper summarizes the methods of predicting heat transfer coefficients in engineering applications. The effects of the temperature ratio between the wall and the fluid on the heat transfer coefficient predictions are studied by summarizing the researches. Through the summary, it can be found that the heat transfer coefficients do show a dependence on the temperature ratio. And these effects are more obvious in turbulent flow and pointing out that the inaccuracy in the determination of the heat transfer coefficient and proposing that the conjugate heat transfer analysis is the future direction of development.
Demonstration and Optimization of Floor Height of 220kV GIS Room in the Indoor Substation
Authors: Li Yan , Wu Peng , Xing Lin , Wang Ning , Cheng Rong , Hu Yuan
Published: November 2021

With the development of cities, the construction of indoor substations and the use of gas insulated switchgear (GIS equipment) are becoming more and more widespread. In this paper, the height of 220kVGIS room in the indoor substation is demonstrated and optimized. On the basis of the collection and analysis of the basic data of each major equipment manufacturer, the height of GIS room is analysed from the expansion, maintenance needs and pressure test, which are two limiting factors. Finally, the optimal height of 220kVGIS room is determined.
Compressed Air Energy Storage and Future Development
Authors: Guo Jingyue , Ma Ruiman , Zou Huiyan
Published: November 2021

Power generation around the world is changing dramatically as a consequence of the demand to lower greenhouse gas releases and present a mix of power supplies. Energy storage technology is considered to be the fundamental technology to address these challenges and has great potential. This paper presents the current development and feasibilities of compressed air energy storage (CAES) and provides implications for upcoming technology advancement. The paper introduces various primary categories of CAES (Advanced Adiabatic-CAES, Liquid Air Energy Storage and Supercritical CAES). Compared with other energy storage technologies, CAES is considered a fresh and green energy storage with the distinctive superiorities of high capacity, high power rating, and long-term storage, and shortcomings of low power density, high transportation losses, and geological restriction. CAES is regarded as a promising technology that is able to be applied in renewable energy production, cogeneration, and distributed energy and microgrid systems. It’s also considered to be integrated with other technologies, such as renewable energy, gas turbine, solid oxide fuel cells, and other systems in the future.
Simulation Experiment on Energy Tower Coupled with Buried Pipe System of Ground-source Heat Pump for Cross-season Heat Storage
Authors: Wang Jianhui , Liu Ziqiang , Liang Yingkai , Peng Guohui , Wang Weiyu , Liu Wei
Published: November 2021

It is proposed to use energy tower instead of solar collector system to store heat for buried pipe system of ground-source heat pump in summer, so as to solve the problem that soil temperature is too low due to unbalanced cold and heat load of GSHP in cold and severe cold area. The simulation results show that the thermal storage power of energy tower is affected by soil temperature and environmental temperature. The lower the soil temperature, the better the thermal storage effect of energy tower system for soil. The thermal storage power and environmental temperature change in a positive relationship. It is proved that the application of cross-season heat storage is feasible for energy tower coupled with buried pipe system of ground-source heat pump in cold and severe cold area.
A Novel Control Method of Low-voltage-ride-through Technique for Asymmetrical Hybrid Energy Storage System
Authors: LI Xiaomeng , Gao Ze , Zhang Zhen’an , Rao Yufei
Published: November 2021

Low-voltage-ride-through (LVRT) capability is an important criterion for the stability of cascaded multilevel energy storage system (ESS). Based on asymmetrical hybrid ESS, a coordinated operating method is proposed to maintain the phase angle of positive-sequence-voltage of battery cells and capacitor cells. To deal with the asymmetrical chains among three phases, its influence on the power distribution is eliminated by modifying the command of battery cells, then the traditional zero-sequence-voltage injection is feasible for asymmetrical situations. Proposed methods can stabilize the dc-side voltage of capacitor cells, maintaining the output current. Finally, the correctness and effectiveness of proposed methods are proved by experiment.
Study on control strategy of output stability of wind-solar reservoir thermal system
Authors: Li Shengshan
Published: November 2021

In view of the landscape reservoir heat output coordinated control demand, based on the topology of the hybrid energy storage system of the three ports heating model, using the sunlight with the electricity output of the complementary and heat accumulation can be regulatory, intends to research a kind of based on photo-thermal storage heat and scenery electricity heating output port control method, in order to achieve the goal of fast and smooth regulating heat output fluctuations, The coordinated output control of integrated wind-landscape storage and heat collection is realized.
Smart grid oriented Internet of Things technology and application analysis
Authors: Zhou Wenting , Xiao Jingfeng
Published: November 2021

In the development of modern society, the Internet itself with the characteristics of diversification and virtualization, has played a good application value. The Internet of Things can realize the interaction and construction of related network resources through the effective integration of physical and virtual bodies. It makes the overall information network communication and power industry structure to achieve the corresponding transformation and industrial upgrading, and ultimately promotes the transformation of social production structure. This provides good convenience for people and promotes the development of the whole society.
Transient overvoltage characteristics in submarine cables of multi-terminal flexible HVDC transmission system
Authors: Feng Man , Li Tao , Liu Jinjuan
Published: November 2021

The overvoltage transient characteristics of submarine cables are one of the key technologies for submarine power transmission. This article takes the submarine cable of Zhoushan Multi-terminal Flexible HVDC Transmission Project as the research object. The MMC-HVDC simulation models at both ends of converter stations are built in PSCAD. The parameters and equivalent models of the flexible HVDC cables are determined, and the submarine DC cable operating overvoltage is calculated by using statistical methods. The simulation results show that the maximum overvoltage of the submarine cable, that is, the maximum overvoltage of the conductor to sheath, the sheath to the armour, and the armour to the ground are 400 kV, 7.27 kV and 0.45kV respectively. The maximum overvoltage when it occurs faults on grid-side or valve-side appears in the middle of the submarine cable. Maximum overvoltage of HVDC single pole grounding fault appears at the connection point of land cable and submarine cable. The simulation results and the discovery of features in this article provide reference in the design, selection, and testing of submarine power transmission equipment.
Online Monitoring of Transmission Line Operation Based on Power Internet of Things
Authors: Zhang Xiaohua , Xue Wenxiang , Wang Shuyuan , Lu Yi , Wang Hui
Published: November 2021

Current monitoring methods of transmission line operation status can not obtain real-time data of distributed distribution transmission line, which leads to a large error in monitoring results. Therefore, a multi-state on-line monitoring method based on power Internet of Things is proposed. Using the gateway of power internet of things to set up network control access mode, build edge computing model, and using AD chip of ADS8365W5300 to obtain the real-time data of massive distributed distribution network, then make a decision on the fault after processing and analyzing the data. This paper constructs an edge computing model which can complete the data processing and analysis in the edge node, and designs the deployment of the edge computing model. By evaluating the faults in the dynamic incremental fault set, the risk state of transmission line in the danger control area is obtained, and a multi-state on-line monitoring method is designed. The experimental results show that the proposed method can monitor the transmission line running state accuratel
Research on the Formation and Solution of the Bullwhip Effect of Electricity Material Reserve
Authors: Zeng Wenlong , Peng Fei , Hong Qiaozhang , Liu Jinsheng
Published: November 2021

With the deepening of the power system reform together with the transformation and development of power companies, the importance of supply chain management has become increasingly prominent. As an important part of the power supply chain management of power companies, the accuracy of electricity material reserves has an impact on the entire process of the company’s supply chain. This article analyzes the reasons for the bullwhip effect in the process of electricity material storage, points out the harm caused by the bullwhip effect, and proposes ways to weaken the bullwhip effect such as improving the accuracy of demand reserves, strengthening inventory management.
Insulator filth monitoring and situation awareness based on ultraviolet pulse and least square method
Authors: Liu Tao , Qu Bo , Li Guolong
Published: November 2021

To monitor the filth state of insulators in time, a method based on ultraviolet pulse method is proposed to monitor the filth status of insulators, which can detect the early corona discharge of insulators by detecting UV signals and determine the degree of insulator filth. On this basis, the response characteristics of spot area to electrical pulse signal are studied and theoretical analysis is carried out, the relationship between spot area and electrical pulse signal amplitude is studied, and the correlation curve is obtained. By observing the change law of image size with the observation distance in ultraviolet image. the experiment found that the image size of UV channel and the image size of visible light channel increased or decreased in approximate proportion with the observation distance and proposed a new method to estimate the “discharge imaging area ” of discharge on the surface of the insulator by using the image information of the visible light channel. According to the discharge “relative spot area mean”, one minute time “number of large spot area image frames” two ultraviolet imaging parameters used to characterize the filth discharge characteristics, combined with the ambient humidity to establish a fuzzy logic reasoning model of the filth state, to achieve the assessment of the filth state of the insulator. By using the proposed UV image processing method, the accuracy of insulator filth detection is improved.
Dynamic data processing method based on generalized least square method
Authors: Yang Zhaoxin , Gu Zhenghua , Zhang Wenqing
Published: November 2021

In this paper, a time domain-processing method is introduced for the dynamic calibration based on Hopkinson bar and shock tube. With a group of accelerometer and pressure sensor data processed in our work, the algorithm for establishing dynamic mathematical model is described in detail. “Generalized least square method for special whitening filter” and the simulation results are given. It shows that this method has the characteristics of simplicity and accuracy, and is especially suitable for the establishment of difference equation model in the data processing of dynamic calibration experiment.
Research on Intelligent Metrological Verification Technology Based on Internet of Things
Authors: Yu Meng , Liu Jianmin , Li Xiaowen , Wang Nana , Wang Fan
Published: November 2021

Intelligent metrological verification is of great significance to improve the accuracy of equipment. Especially in the current situation of rapid increase in residential electricity consumption, electric energy meters have received widespread attention from the society as an important device that affects electricity trade settlement. In this research, this article will be based on the technological environment of the Internet of Things. After the analysis of the intelligent metrological verification system, the key technical means will be highlighted, including automatic sealing technology, automatic connection and disconnection technology, and cycle simulation system design. This article provides support for the verification system construction of the metrological center.
Smart substation network quality monitoring and fault prediction
Authors: Li Chao , Peng Qi , Wang Dehui , Luo Linglu , Zuo Huanhuan
Published: November 2021

The smart substation communication network is the basis for information sharing of various devices in the substation. Its operation status has an important impact on the safe operation of the substation and even the power grid. Therefore, real-time status monitoring of the smart substation communication network is becoming more and more important. Aiming at the problems of single dimension, insufficient real-time performance and manual fault analysis in existing substation communication network state monitoring technology, this paper proposes a method of smart substation communication network state monitoring and fault prediction based on network communication quality. This paper uses switch ACL technology and coloring technology to obtain communication quality indexes such as bandwidth utilization, delay, and packet loss rate in real time; based on a multi-dimensional evaluation algorithm, a comprehensive evaluation model of network communication quality is constructed; the model of the relationship between abnormal network communication quality and failures is established. Finally, real-time monitoring of network communication quality and fault prediction are realized. The application analysis in a typical 110 kV substation shows that this method can effectively evaluate the network communication quality and accurately predict failures, and can guide operationer and maintenaner to quickly restore the normal operation of the communication network.
Topology identification method of distribution network based on branch active power
Authors: Liu Biqi , Wang Danni , Li Yunpeng , Qiao Lin , Chen Shuo
Published: November 2021

Because of low measurement redundancy and frequent switch changes, it is difficult to identify the correct topology structure. In this paper, a topology recognition method of distribution network based on branch active power is proposed. Firstly, branch active power residual algorithm is used to identify the topological structure. The topology obtained by this method has the highest matching degree with the real-time measured data. Then genetic algorithm is used to optimize the inverse recognition of power grid topology. The numerical example shows that the method is reasonable, effective, rapid and simple. It also has good adaptability with a large number of measurement errors.
An optimization method of clock synchronization for large-scale regional power network based on IEEE 1588
Authors: Zuo Yue , Wang Xingcai , Zhang Bo
Published: November 2021

At present, mobile devices generally use GPS, Beidou and other satellite time service methods to obtain time, but the clock synchronization based on IEEE 1588 protocol still has deviation. To solve this problem, a clock synchronization method is proposed to improve IEEE 1588 protocol. Based on the analysis of IEEE 1588 protocol, the clock deviation and frequency deviation which affect the synchronization accuracy are modeled. The second-order Kalman filtering algorithm is used to recursively deduce the clock deviation and frequency deviation, and the Allan variance is used to verify the noise characteristics and constantly correct the clock deviation. Finally, the improved effect is verified by relevant experiments. The results show that the improved system can improve the synchronization accuracy.
Application of Trusted Computing Technology in Active Defense of Smart Substation
Authors: Chen Liandong , Yang Tao , Li Gang , Liu Xin , Lu Ning , Cheng Kai , Xin Xiaopeng
Published: November 2021

Nowadays, most security systems mainly use firewall, intrusion detection, virus killing and other technologies to defend against external attacks. This passive defense mode has low efficiency and high false positive rate, and active defense technology can solve these problems to the greatest extent. At present, the intelligent substation is in the development stage with weak security. After a large number of terminals are connected, although the operation efficiency of the whole station is improved, it also brings more risks. This paper takes the access security of terminal equipment in intelligent substation as the research object. By mining the security vulnerabilities of substation, an active defense method based on trusted computing is proposed, the applicability and efficiency of trusted computing technology in the field of substation active defense are proved and the effectiveness of the method is verified to realize the trust guarantee of the whole process of terminal access to intelligent substation.
Application of millimeter wave radar in safety obstacle avoidance of crane in electric power construction
Authors: He Wei , Hu Shenglei , Pan Wang , Zhang Lijuan
Published: November 2021

When the traditional electric construction crane safely avoids obstacles, obstacles are only detected according to the parameter estimation results, which is greatly affected by the external environment and takes a long time to avoid obstacles. Aiming at the above problems, the safety obstacle avoidance method of electric construction crane based on millimeter wave radar is studied. The millimeter wave radar is used to obtain the millimeter wave radar detection signal for crane safety obstacle avoidance. According to the impulse response of millimeter wave radar detection echo, the obstacle location mark and distance estimation are carried out, and the distance and azimuth information between the crane and the obstacle are calculated. By optimizing the safe obstacle avoidance path of electric construction cranes, the safe obstacle avoidance of electric construction cranes can be realized. Through comparative simulation experiments, it is verified that the design method takes less time to avoid obstacles, has higher efficiency, and does not collide with obstacles in the workspace in the process of movement, which verifies the effectiveness of the method.
Intelligent Driving Detection System Based on unmanned Driving Background
Authors: Wang Hongqi , Chen Shouman , Wen Yahong , Zhou Chaofan
Published: November 2021

Unmanned driving is the future development direction of the automobile industry, and intelligent driving detection is one of the important research topics. In order to improve driverless technology and traffic safety, this design is based on FPGA technology to design a driving detection system, combined with off-chip SDRAM’s high-speed, large-capacity cache and image processing related algorithms, and it will achieve the function of acquiring target image, cache, detection and display. Finally, the FPGA development board is used to test the driving detection system, which demonstrates that this driving detection system can better improve the safety monitoring problems in unmanned driving. At the same time, the system’s frame rate is close to 55pfs, which has practical significance and application value.
Analysis and Design Based on the Operation Mode of Power Electronic Transformer in Smart Grid
Authors: Ma Runzhuo
Published: November 2021

Power electronic transformers(PET) are the key energy conversion equipment in the operation of modern smart grids, the main function of PET is to achieve the conversion of AC voltage to AC voltage, while taking into account the DC ports. This article mainly studies three-stage power electronic transformers based on three-phase uncontrolled rectifier, full-bridge isolated DC-DC converter and three-phase inverter. The operation mechanism and actual working process of the three parts of the PET are analyzed respectively, and the transformer is simulated and analyzed based on the Matlab/Simulink simulation platform. The rectifier converts the AC voltage on the grid side into a rippled DC voltage; the DC-DC converter transforms the obtained DC voltage, taking into account the access of the DC ports; the inverter converts the obtained DC voltage into AC voltage through unipolar modulation and connects to the grid. The experimental results show that the PET constructed in this way can operate safely and stably, which has good voltage conversion and electrical isolation functions, and can be connected to DC loads.
Intelligent alarm data noise reduction for power systems based on singular value decomposition
Authors: Chen Chen , Man Hongren , Liu Xiu
Published: November 2021

The noise types of power system intelligent alarm data are complex. When reducing the intelligent alarm data, the profile noise statistics of the noise data are large, resulting in the actual noise reduction value is too small. To solve this problem, a power system intelligent alarm data noise reduction method based on singular value decomposition is designed. The selected normalized decomposition matrix iteratively processes the original matrix, the singular value decomposes the power system alarm data, sets an estimation quantity within the paradigm of the alarm data, controls the noise profile noise statistics, characterizes the noise alarm data structure, uses the SC algorithm to process the cluster basis vectors in the noise data structure, and constructs a repeated iterative convergence process to realize intelligent data noise reduction processing. The original alarm data within a known power system is used as test data, the power system alarm window is set, and the power system alarm data singular values are circled. The data mining-based alarm data noise reduction method, the regularized filter-based alarm data noise reduction method and the designed data noise reduction method are applied to the noise reduction process, and the results show that the designed data noise reduction method has the largest noise value and the best noise reduction effect.
Remote acquisition of insulator icing flashover signal based on frequency optimization of ring-shaped intelligent current sensor
Authors: Lv Qiancheng , Tian Bing , Liu Zhong , Wang Zhiming , Yin Xu , Sun Hongdi , Luo Bofeng
Published: November 2021

In order to improve the safety of power grid operation and avoid the hidden danger in the process of power supply, a remote acquisition method of insulator ice-covered flashover signal based on the frequency optimization of ring intelligent current sensor was proposed. According to principle of take electricity by capacitance, transmission line, current sensor, current sensor B and double rectifier circuit composed of parallel resonant magnetic circuit for electric model. By monitoring the current sensor and current sensor B the secondary side of induction electromotive force, magnetic core KaiQi gap equivalent permeability values, such as through the calculation of current sensor parameters of iron core and coil number of turns. In this paper, the current sensor is optimized to improve the power monitoring effect, and the remote acquisition of the flashover signal of insulator icing is realized. The experimental results show that. This monitoring method can effectively monitor the maximum load power, load resistance and load voltage of the model when the current value is different. In the face of impedance branch resonant, resonant and open air gap and other circumstances, can effectively monitor the power taking situation, a wide range of applications.
Research on output power quality control technology of three-phase inverter
Authors: Zhang Yinfeng , Shao Ying , Lei Kang , Wang Kongxian
Published: November 2021

With the wide application of new energy and distributed generation system, high-performance inverter plays an important role as the key link of power system access. Its performance determines the quality of output power. Therefore, the output power quality control technology of three-phase inverter has become one of the important research directions in this field. This paper introduces the current main inverter power quality control methods, summarizes and compares the advantages and disadvantages of a single control method, and points out that the composite control method is the development trend of inverter output power quality control technology.
Influence of antenna half-power beam width on equipment under test volume in radiation disturbance measurement
Authors: Zhou Yi , Zhang Dong , Xu Xiaoguang , Li Jun
Published: November 2021

Through the study of the latest radiation disturbance measurement standards, the difference between test volume and equipment under test volume was compared and analyzed. Different types of antennas will be used in the radiated disturbance measurement in terms of the different frequency range. Various antennas have kinds of directional characteristics. This article analyzes the influence of antenna half-power beam width on the equipment under test volume, especially on the height, from three frequency ranges. Furthermore, taking the typical horn antenna as the starting point, as well as the formula of volume with antenna half-power beamwidth, the relationship between equipment volume and frequency is calculated. Finally, the influence of antenna half-power beam width on the equipment under test volume is obtained.
Thermal Analysis of Main Components in The Design of High-power Tetrode
Authors: Zhong Haoran , Chen Wenbo , Gong Xueyu , Wu Honghu , Yang Puqiong , Luo Yongjie
Published: November 2021

High-power tetrode is a key component in ion cyclotron resonance heating system, as the final amplifier component to increase the RF power to the megawatt level. Thermal analysis is of important significance to the development and use of high-power tetrodes. In this paper, the trajectory of particles during the operation of the tetrode is obtained by CST particles studio, and its energy conversion is analyzed through the simulation results. Then the grid, anode, and support structure of the tetrode are analyzed thermally in Ansys Workbench, and the results are helpful to the design of the heat dissipation structure of the tetrode.
Muti-level voltage synthetic voltage direct power flow controller
Authors: Cao(Cao) Xinwei , Zhang(Zhang) Youjun , Sun(Sun) Zhengzheng
Published: November 2021

Aiming at the defects of DC energy storage elements, complex structure and large volume of unified power flow controller (UPFC), the paper combines flying capacitor multilevel technology and voltage vector synthesis technology with unified direct power flow controller. A three-level direct power flow controller (3L-DPFC) and a new control strategy are proposed. By obtaining the power parameters of the receiving end and substituting them into the derived calculation formula, the compensation voltage can be deduced to adjust the phase and amplitude, and the change relationship between the compensation voltage and the power parameters of the receiving end can be calculated through multiple groups of data, so as to adjust the active power flow and reactive power flow in the power grid. Compared with the unified direct power flow controller, it has the advantages of no DC energy storage element, small volume, simple structure, and the voltage stress of each switch is reduced by half, which reduces the failure rate and economic cost of the controller. In the paper, the topology and control strategy of three-level synthetic DPFC are described in detail, and its buck AC conversion theoretical analysis is verified by simulation.
Study on Environmental Adaptability of Metal Plate Fuel Cell
Authors: Wang Hailiang , Feng Junxiao , Li Lanyun , Tu Zhengkai , Zhou Bo , Wang Guanqiong , Xu Qinshu , Xu Jianping , Gao Jinghui
Published: November 2021

As a main task of national key project (2018YFC081000)“emergency power under the special environment systems research and application demonstration”, Study on Environmental Adaptability of Metal Plate Fuel Cell.the paper focus on the key technologies needed to be developed of researching PEMFC system to adapt to the special environment of high temperature, high humidity, high salt, high cold and high altitude;this topic reviews the impact of plasma exchange membrane fuel cell and climate environment on such emergency power supply equipment, and uses Au@TiN as a metal bipolar plate of proton exchange membrane fuel cell. After a series of tests, it proves the excellent operation characteristics of the fuel cell reactor in “4-high” environment.the study showed that after constant 1.0 V (vs SHE) potential polarization, the size order of different coating corrosion currents is: gold plated> stainless steel> carbonization;In a high altitude environment, the optimal air intake parameters are obtained by numerical simulation and optimization of air pressure, air volume, wind speed, air excess coefficient and other parameters;In a high-temperature environment, the problem of the metal bipolar fuel cell supply system can be solved by improving the flow structure of the air side to increase the heat exchange area and the air capacity;In the high-cold environment, the shutdown pulse sweep scheme is adopted, and the rapid start of hydrogen battery supply system is realized by using hydrogen catalytic reaction assisted heating.