bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Characteristics of CMOS Inverter based on Multisim and Cadence
Authors: Xu Haoran , Ding Jianghua , Dang Jian
Published: November 2021

Known as complementary symmetrical metal oxide semiconductor (cos-mos), complementary metal oxide semiconductor is a metal oxide semiconductor field effect transistor (MOSFET) manufacturing process, which uses complementary and symmetrical pairs of p-type and n-type MOSFETs to realize logic functions. CMOS technology is used to build integrated circuit (IC) chips, including microprocessors, microcontrollers, memory chips (including CMOS BIOS) and other digital logic circuits. CMOS technology is also used in analog circuits, such as image sensors (CMOS sensors), data converters, RF circuits (RF CMOS), and highly integrated transceivers for various types of communications. Based on multisim 14.0 and cadence, the characteristics and performance of CMOS inverter are studied by simulation.
Wireless power transfer system based on frequency and impedance matching hybrid adjustment against system detuning
Authors: Yuan Zhengnan , Fu Pengcheng , Lu Guangshuai , Cao Pengfei
Published: November 2021

System detuning caused by a variation in the distance between the transmitting and receiving terminals can greatly reduce the transmission power and efficiency of a magnetic resonance-coupled wireless power transmission (WPT) system, which limits the WPT application scope. This paper proposes a magnetic resonance coupling wireless power transmission system, which is based on jointly and continuously adjustable frequency compensation (CAFC) and two-transistor-controlled variable capacitor circuits (TCVCs). Therefore, this system can reach the resonant state by using CAFC and two-TCVCs when the transmission distance is changed. The proposed system can adaptively adjust combinations of the operating frequency and equivalent compensation capacitor’s capacitance to achieve impedance matching avoiding the phase difference caused by the imaginary part of the impedance, thus maintaining stable transmission efficiency under the condition of transmission distance variation. Compared to the traditional magnetic coupled resonant circuit based on impedance matching or variable resonant frequency, the proposed system achieves higher efficiency and stability and dynamic distance adaptation.
Research and classification of wireless power transfer with relative application
Authors: Qiu Muchen
Published: November 2021

In this paper, wireless power transfer (WPT) will be discussed in its research and application. The basic information like the reason why devices choose to use wireless power and the concept of typical WPT types is introduced. The wireless power transfer system can be divided into 5 diverse types by the theory of power transmitting, and the working principle will be introduced separately. Then, the detail of WPT via magnetically-coupled resonance is mainly discussed, including the analyzing methods, optimization scheme and the current problems. Finally, this paper give two examples on medical use and mobile phone battery charging. Using the technology of WPT, the problem of the medical tiny robots battery charging is solved, and it provides a more convenient method of charging the mobile phones without the cables. The wireless power transfer technique has potential advantages and broad prospects, which is of vital significance in power transfer development.
Characteristics and Applications of Superconducting Magnetic Energy Storage
Authors: Huang Yuyao , Ru Yi , Shen Yilan , Zeng Zhirui
Published: November 2021

Energy storage is always a significant issue in multiple fields, such as resources, technology, and environmental conservation. Among various energy storage methods, one technology has extremely high energy efficiency, achieving up to 100%. Superconducting magnetic energy storage (SMES) is a device that utilizes magnets made of superconducting materials. Outstanding power efficiency made this technology attractive in society. This study evaluates the SMES from multiple aspects according to published articles and data. The article introduces the benefits of this technology, including short discharge time, large power density, and long service life. On the other hand, challenges are proposed for future study. The high energy requirement of the cooling system and carbon emissions are some of the drawbacks of SMES. It’s found that SMES has been put in use in many fields, such as thermal power generation and power grid. SMES can reduce much waste of power in the energy system. The article analyses superconducting magnetic energy storage technology and gives directions for future study.
Application of Digital Twin Technology in Energy and Power Industry
Authors: Liang Xueqing , Du Shuming , Zhao Xiaofan , Liu Chao
Published: November 2021

Constructing digital twin of physical entity and analyzing twin data, and transfer learning method can be used to transfer the characteristics of twin to physical entity for analysis. This paper mainly studies the application of digital twinning technology in the energy and power industry. Aiming at the energy saving and control problem of building energy demand terminal, the fuzzy adaptive PID control algorithm is used to simulate the indoor HVAC system and lighting system, so as to solve the indoor temperature and illumination intensity are greatly affected by the weather, time-varying and unpredictable factors. By comparing with the conventional PID, we can see that the fuzzy adaptive PID controller adjusts faster, the output duty ratio is more accurate, and can achieve better control effect.
Hierarchical Control Strategy for Microgrid Based on Finite-time Consensus Algorithm
Authors: Tang Binfeng , Huang Ying
Published: November 2021

In order to overcome the shortcomings of centralized control strategy for microgrid, a hierarchical control strategy based on finite-time consensus algorithm is proposed in this paper. Based on the droop control, the control strategy uses the finite-time consensus theory of multi-gent system to solve the optimal power generation value of the system, and adjusts the droop coefficient to make the power generation power of the power supply the optimal value. Then the compensation of frequency and voltage is introduced by multi-agent technology to stabilize the system frequency and voltage at rated value.
A Smart Grid Planning Method with Coal-to-electricity Based on Multifactor Adaptability
Authors: An Jiakun , Yang Shuqiang , Wang Tao , He Chungaung , Jia Hongjie , Mu Yunfei , Dong Xiaohong , Zhao Yang , Tan Xiaolin , Guo Wei
Published: November 2021

In order to reduce coal pollution and improve air quality in winter, many cities in northern China began to promote coal-to-electricity, and a series of policy subsidies were released accordingly. With the implementation of coal-to-electricity, the characteristics of power network has been changed significantly and the traditional planning method is no longer applicable. To meet the needs of coal-to-electricity engineering, a smart grid planning method with coal-to-electricity based on multifactor adaptability is proposed in this paper. First, the coal-to-electricity load characteristics is analysed, and typical parameters is proposed based on the actual operation data, which considers the impacts of different types of equipment and breaks through the modelling difficulties of coal-to-electricity characteristics. Then, a smart grid planning method with coal-to-electricity based on multifactor adaptability is set up, which combines the influence of transmission capacity for each equipment, the investment capacity for each participant, and the social acceptance of the electricity price. Based on this model, the technical, economic, and environmental benefits of coal-to-electricity modification are coordinated. The application shows that the proposed method is concise and effective and provides useful suggestions for determining the coal-to-electricity scale, network planning and compensation policy, which supports the implementation of coal-to-electricity.
Research on Data Acquisition Technology of Distribution Automation Based on Internet of Things Communication Protocol
Authors: Wu HuiChao , He MingYi , Wei HaiZeng
Published: November 2021

With the gradual application of the Internet of Things technology in the field of distribution automation, distribution terminals gradually adopt the Internet of Things protocol to communicate with the master station system of distribution automation. while the master station system of distribution automation supports the access of the traditional power dedicated protocol terminal, it faces how to solve the problem which how to access the distribution terminal of the network communication protocol. This paper proposes the MQTT protocol data acquisition architecture based on the existing master station system of distribution automation system. Through the research on the transmission characteristics of power distribution service data and MQTT protocol, the message structure of the MQTT protocol carrying power service data and the source maintenance process of the equipment model are designed., It realizes the direct collection of the terminal data of the distribution Internet of Things in an object-oriented way, gives full play to the value of the existing distribution master station, reduces investment costs, and saves system maintenance workload.
Research on Multi-point Hopping Communication System in Power Network Based on Information Fusion Model
Authors: Yu Lifeng , Hu Kaibo , Lv Jiachen , Xia Zhiling
Published: November 2021

Multi-source heterogeneous information will cause access burden to the power network, resulting in poor performance of multi-point hop communication. Therefore, a multi-point hop communication system based on information fusion model is designed. The IEC61970/61968CIM is selected as the integrated bus general data acquisition scheme of the information fusion model. The local-global distributed information fusion mechanism is used to realize the communication of the power multi-point hop communication system. In this paper, the artificial neural network algorithm is used to fuse local information features, and according to D-S evidence theory, the global decision-level fusion is carried out from both the spatial domain and the time domain. Through the information fusion model, the multi-point hop communication information in the power network realizes efficient transmission. The experimental results show that the application of the system in the power network to implement multi-point hop communication, the packet loss rate is less than 0.25%, the transmission delay is less than 30ms, and the communication performance of the power network is improved
Design of distributed timing task scheduling system for smart grid
Authors: Tang WenSheng , Wang JinZhi , Fan Tao
Published: November 2021

With the rapid development of information technology and the growing scale of enterprise development, more and more enterprise application systems appear due to business scenarios, requiring the system to execute the specified business operations at the planned time, which is the demand of “timed tasks”. The rapid growth of business volume makes the number of timed tasks also increase massively, and the importance of timed task application scenarios requires more and more strict guarantee of reliable triggering of tasks. In this paper, to address these problems, we design and implement a distributed system providing timed task scheduling service based on Quartz, an open source lightweight job scheduling framework, and realize business modules such as timed task control service, trigger execution, lock grabbing trigger, unified configuration management, task load balancing and log management. The system has been tested and put into operation, and has completed the requirements well and achieved the design goals.
Research on residual current detection system of substation alternating current power supply
Authors: Li You , Xia Chuanfu , Zhuang Yuan , Liao Baoquan , Huang Shuai
Published: November 2021

Residual current monitoring of substation is essential to prevent electrical fire and plays an important role in the safety of substation. This paper studied residual current detection technology of substation AC power supply, and proposed a residual current detection system composed of three devices: sensing terminal, management terminal and monitoring terminal. The design could solve some difficult problems such as the secondary line caused by equipment installation, fault wave recording, fault location analysis, and early warning based on analysis of big data. The study could improve the intelligent level and maintenance efficiency of residual current monitoring in substation.
Intelligent detection method of abnormal state of power equipment based on infrared and visible image information
Authors: Liu Tao , Qu Bo , Li Guolong
Published: November 2021

Infrared thermal imaging cameras are usually used to detect the thermal state of the equipment. According to the heat radiation situation and temperature value emitted by the equipment, the thermal failure of the equipment is inferred, and whether the equipment is working is verified properly. This paper analyzes the thermal imaging principle of infrared technology and the characteristics of infrared images, and quantifies the surface temperature indicators of insulators. Through infrared and visible light image information, the pollution degree of insulators can be detected, and the abnormal condition of the equipment can be checked. The evaporation of moisture on the surface of the insulator mainly depends on the assumption that the surface heats up. A method for analyzing heat on the surface of wet-contaminated insulators is proposed, and the judgment conditions for arc generation in the drying zone and the drying zone and the heating models of the insulators in different operating conditions are established. The computer simulation results reveal the distribution of heat on the surface of insulators under different operating conditions, and the influence of the occurrence of drying zone and drying zone arc on leakage current and heating. The infrared thermal imaging test results of wet-contaminated insulators show that the model is reasonable and provides theoretical support for infrared thermal imaging detection of insulator contamination levels.
Research on the optimal strategy of pumped storage power station to provide multiple time-scale reserves
Authors: Li Xiaomeng , Yu Xiaopeng , Gao Ze
Published: November 2021

In the background of peak carbon emissions and carbon neutrality, renewable energy generation (REG) will become the main generation form in the future power system. Simultaneously, the randomness and volatility increase the reserve requirement in the different time scale. Increasing importance has been attached to energy storage in the aspect of reserve, as energy storage has the advantages of power flexibility and relatively low reserve cost. Trading off the benefits of energy storage in the energy market and the reserve market to maximize its benefits is of great significance to the economic operation and investment of energy storage. In this regard, taking the pumped storage power station (PSPS) as an example, this paper establishes an optimal decision-making model for PSPS to participate in the energy market and to provide reserve services. In addition, an optimal decision model for PSPS to provide multiple reserve services is established. The analysis finds that the power reserve capacity provided by PSPS at different time scales have little impact on each other, but their storage capacity requirements are mutually restricted. Case studies show that the total revenue of the PSPS is significantly increased through providing reserve service. The PSPS may even bid all its capacity to provide reserve service when the compensation price reserve reaches a certain level. In addition, the total revenue of PSPS when providing multiple time-scale reserves is higher than that when providing reserve service at single time scale.
Research on the Application of Renewable Energy in DC Data Center
Authors: Bai Xingyu
Published: November 2021

With the rapid development of the information technology industry, the demand for data centers is gradually expanding. As the foundation of carrying many information technology services, data centers have been built and put into use on a large scale. At the same time, the characteristics of huge energy consumption are more obvious. Due to the defects of low utilization rate, heavy pollution and limited reserves of traditional fossil fuels when supplying energy for data centers, the development of green renewable energy has become an inevitable demand. This paper studies the key technologies involved in supplying power to DC power supply data center with renewable energy, and makes a case to compare the DC power supply system and the AC power supply system. This paper also pays attention to the technology of energy storage in data center, and makes an analysis to prove the advantages of energy storage data center. In addition, this paper studies and summarizes the application of multi-station integration technology and other issues.
Energy Storage Planning of Park Energy System Based On Multi-Dimensional Digital Twin Technology
Authors: Xiong Tianlong , Yang Chao , Cheng Qing , Yang Xianlong , Lin Shu
Published: November 2021

The existing energy storage planning methods have the problem of imperfect equipment mathematical model, resulting in small installed capacity of renewable energy. An energy storage planning method of Park energy system based on multi-dimensional digital twin technology is designed. This article explains the basic connotation of multi-dimensional digital twin technology and park energy system, and obtains feedback information. Combined with the energy consumption of industrial users, the park’s electricity load is predicted. We used the multi-dimensional digital twin technology to construct the mathematical model of the equipment, extracted the energy conversion law, optimized the energy storage mode of the energy system, and achieved zero heat emission. Case analysis results: the average installed capacity of renewable energy after optimization is 2349.6 kW, 626.6 kW higher than that before optimization, indicating that the energy storage planning method integrating multi-dimensional digital twin technology has a broader application prospect.
Lithium battery loss model and economic optimal control strategy for secondary frequency regulation in power system
Authors: Zhang XiaoChi , Sha Xu , Zheng ZhiTong , Gong Jie , Li Yuan , Sun Kai
Published: November 2021

Lithium battery energy storage system (ESS) has fast response speed, but it is in service for a long time. Therefore, in the research of secondary frequency regulation, it is necessary to establish a battery model that can reflect the short-term polarization and estimate SOC accurately under long-term service. Therefore, we propose a method of variable parameter loss model of lithium battery suitable for secondary frequency modulation of power system and optimize its control strategy based on the relationship between the independent variable SOC and the internal electrical parameters of the battery. Firstly, we discretize the state equation of single cell to obtain the PNGV model with variable parameters. Then the SOC estimation method is improved by using the modified extended Kalman filter method. Finally, we did an analysis about the economy of the ESS participating in secondary frequency regulation by using the loss model, and the optimal control strategy is designed. The HPPC experiment of the ESS unit is designed by Simulink, and the accuracy of the simulation and experimental curves has been analyzed. Finally, the economic differences between the traditional control strategy and the optimal control strategy considering loss are compared. The results show that the error of the variable parameter model in the fitting experiment is no more than 0.41%, and the accuracy of SOC estimation is 12.96% higher than that of the traditional estimation. The economy of the optimized control strategy is 15.38% higher than that of the traditional control strategy.
Capacity configuration optimization and analysis for multi-energy complementary microgrid in hydropower station considering the renewable energy accommodation
Authors: Gao Yang , Liu Bin , He Jinyu , Zhang Kai , Liu Li , Jin Li , Ren Juguang
Published: November 2021

Aiming at the problems of large short-term fluctuation, strong randomness and difficulty to consume of renewable energy generation, it is an important way to integrate abundant wind and photovoltaic (PV) power into hydropower stations to promote the consumption of renewable energy sources (RES). A hydro-wind-PV and energy storage multi-energy complementary microgrid (MECM) model is proposed to meet the demand of load supply and RES consumption. Firstly, according to the characteristics of load and resource endowment, the MECM is established in a hydropower station. Secondly, according to the two different objectives of load self-sufficiency and RES consumption, the mathematical model for the capacity configuration optimization of MECM was proposed. Finally, combined with the practical case study, the effectiveness and practicability of this scheme are verified, and different configuration schemes are discussed based on different objectives.
Research on key technology of 3D digitization for secondary system of power grid based on model application analysis
Authors: Liu Qingquan , Li Tiecheng , Zang Qian , Ren Jiagnbo , Zhao Yuhao , Hao Xiaoguang
Published: November 2021

In order to solve the problems of long development time, poor expansibility and small application scope in the digital design of secondary system of intelligent substation at present, this paper puts forward the 3D assembly techniques based on the expanded model by analyzing the integration of secondary model files of intelligent substation. In the design process of this method, the relationship between primary equipment and secondary equipment, the mapping between logical circuit and real circuit are fully considered. By using standard family library techniques, file analysis techniques and automatic mapping techniques, the coupling between physical model and logical relationship is realized. Taking the actual 220kV intelligent substation as the pilot, the three-dimensional model in secondary system simulation analysis, online monitoring and the application of fault diagnosis shows that the techniques can effectively improve the efficiency of three-dimensional design and maintenance of secondary system.
Online cleaning method of power grid energy anomaly data based on improved random forest
Authors: Chen Ke , Wang Hongkai , Ying Zhangchi , Zhang Chengxin , Wang Jiaqi
Published: November 2021

Aiming at the problem of high root mean square error of traditional power grid energy anomaly data online cleaning, a power grid energy anomaly data online cleaning method based on improved random forest is designed. Firstly, an outlier data recognition model of isolated forest is designed to identify outliers in the data. Secondly, an improved random forest regression model is established to improve the adaptability of random forest to mixed abnormal data, and the data trend is fitted and predicted. Finally, the improved random forest data cleaning method is used to compensate the missing data after removing the mixed abnormal data, so as to clean the abnormal energy data of the power grid. The experimental results show that when the amount of power grid energy anomaly data increases, the cleaning root mean square error of the experimental group is significantly lower than that of the control group. The method in this paper solves the problem of high root-mean-square error in the online cleaning of abnormal data of traditional grid energy.
A FPGA-based parallel method of bridge data compression
Authors: Zhang Jianlong
Published: November 2021

With the rapid development of computer technology, sensor technology, and communication technology, people have gradually designed and continuously improved the health monitoring system of bridge structure. Due to the uninterrupted long-term work of the bridge monitoring system, the long-term operation of a large number of sensors will generate massive amounts of data, and a lot of data to be transmitted from the data collector at the bridge site to the data monitoring center requires the use of a wireless network with limited speed, which will consume a lot of time, thereby bring such negative effects as reducing transmission efficiency, reducing throughput, increasing transmission costs, and affecting the entire bridge inspection system. This paper proposes a parallel compression method of LZSS data based on FPGA, which can compress the incoming data from the sensor system in parallel in the data acquisition system to improve the transmission efficiency, increase the throughput, and reduce the transmission cost.
Short term wind power interval prediction based on VMD and improved BLS
Authors: Zhao Yang , Wen Chuanbo
Published: November 2021

Aiming at the problem of wind power interval prediction, a short-term wind power interval prediction model based on VMD and improved BLS is proposed. Firstly, the complex wind power time series are decomposed by variational mode decomposition to reduce the non stationarity of wind power. Then an improved broad learning system (BLS) is established to predict the power and error of each component, and a weight is given to the prediction error of each component. The sparrow search algorithm (SSA) is used to optimize the weight, and the width of the prediction interval is obtained by adding the power and error prediction values. The experimental data show that the proposed model improves the accuracy of prediction interval.
Research on Synchronization Mechanism of Artificial Intelli-gence Model Based on Belief Measure and Its Application in Pumped Storage Power Station
Authors: Dong Jinliang , Zhang Xu , Li Haijiang , Song Wenzhi , Guo Jinglin
Published: November 2021

For the security monitoring of pumped storage power station, a model synchroniza-tion mechanism for cloud edge cooperation framework is proposed. The method uses the belief function to describe the threshold and uses the ping-pong operation strategy to update the model alternately, which solves the problem of artificial intelligence model synchronization and update of edge equipment. The cloud is based on Baidu BML platform, the edge uses customized servers, and the average model update cycle is about three months.
A New Hybrid Magnetic Coupler for Large Misalignment Tolerance in Inductive Power Transfer System
Authors: Hao Zhongxiu , Fu Pengcheng , Cao Pengfei
Published: November 2021

Wireless charging has been widely used in a variety of applications. However, pad misalignment can influence system parameters that can lead to increased losses as well as reduction in power throughput. In this article, a new coupler based on solenoid-quadrature coils (SQ) is proposed. By combining with hybrid compensation networks, this coupler can stabilize the system mutual inductance within a certain offset range in order to keep power throughput at a certain level. As a result, this coupler can greatly improve the anti-misalignment capability of the wireless charging system. A 20W prototype is developed and tested in the lab. The experimental results validate that the proposed hybrid SQ-SQ coupler system has an improved misalignment performance.
Effect of F Functional Modification on the Stability and Electronic Structure of Borene
Authors: Sun Cuicui , Liu Mengmeng
Published: November 2021

Since the discovery of graphene, two-dimensional materials have quickly won widespread attention in the academic community. Borene is a two-dimensional isomer of boron and the lightest element Dirac material. It becomes the latest and promising two-dimensional material due to its unique structure and electronic properties. In the periodic table, B is a close neighbor of C and has a certain similarity with C. It can also form a hexagonal honeycomb structure. An additional B atom is added to the center of the ring to form a triangular lattice borene. The triangular borene has surplus electrons and belongs to a multi-electron state, which is equivalent to a metastable structure. In this paper, the first principles are used to study the F functionalized modification of the triangular borene. The aim is to transfer the surplus electrons in the system, and probe its structural stability and electronic structure characteristics. The study found that functional modification significantly improved the stability of borene. This can provide feasible ideas and practical guidance for the experimental synthesis of stable boronene.
Design and Analysis of CFETR CS Coil and Pretension Structure
Authors: Liang Zitong , Jin Langzhou
Published: November 2021

The coil and the pretension rod play important roles in the central solenoidal coil system of Tokamak. Therefore, the analysis of the coil and the pretension rod in the normal operating environment is essential for the facility’s construction. In this paper, the 3D model of the two parts mentioned above is built based on SolidWorks. Subsequently, the simulations are carried out to revert the real operation environments following the fields, loads, and boundary conditions. Then, we compare the official analysis results of the corresponding parts in the central solenoidal system of the China Fusion Engineering Test Reactor (CFETR) based on the results from COMSOL. Compared with the official analysis, the error is about 1.3% for the maximum magnetic field and about 0.53% error for the outer part, respectively. As for the pretension rod, simulations are carried out based on the finite element analysis software ABAQUS. The Von mises and the maximum principal stress are 140.1 MPa and 168.4 MPa, which is much lower than the material’s yield stress (205 MPa). The safety factor is 1.78, larger than the critical failure value 1. According to our results, the rationality of the CFETR central solenoidal coil system design is re-examined and verified.
Application of molecular dynamics simulation in self-assembly
Authors: Fang Mingjia
Published: November 2021

During the past few years, numerous studies have been done in self-assembly. Among most of these studies, Molecular Dynamic Simulation is widely used to construct the experiment model. This work firstly introduced three practical applications of MD simulation in self-assembly. Then, two main kinds of simulation are discussed including all-atom simulation and coarse-grained simulation, together with the way of thoughts before the simulation start. It is found that researchers always start with the whole analysis of the substances that need to be studied. It helps to confirm the appropriate model that can apply in the simulation naturally. Besides, depended on the principles that need to be studied, the way of establishing the simulation system varies, ranging from separation experiment in both types of simulation to the change of essential parameters. Furthermore, the adoption of L-J potential in MD simulation proves to be a wise option on account of its convenient and simple model. It is remarkable that, considering some small details like the differences between implicit and explicit solution, classical Martini force field is replaced by Dry Martini force field.
Performance and Optimization Study of R290 as Alternative Refrigerant for R22 in Low Temperature Heat Pump System
Authors: Zhang Yun , Liu Cichong , Li Wanyong , Shi Junye , Chen Jiangping
Published: November 2021

This paper mainly studies the replacement performance of R290 in R22 low temperature heat pump system from the experimental point of view. By comparing the performance differences under different working conditions, it is found that when R22 is directly extracted from the original system and filled with R290, the heat capacity and COP of the system are attenuated, and the compressor discharge temperature and pressure of the R290 system are higher than those of the original R22 system in low temperature environment. Through the analysis of the system components, it can be considered that the main reason for the above phenomenon is that the compressor displacement of the R22 system is too large and does not match the R290 system. Therefore, in order to meet the safety requirements of the system and improve the overall performance of R290 in the low temperature heat pump system at the same time, it is considered to replace the compressor with a smaller displacement which is more matched with R290 in the system. The experimental results show that the compressor displacement optimization of the R290 low temperature heat pump system can effectively reduce the exhaust temperature and pressure of the system and improve the overall performance of the system. The COP of the optimized R290 low temperature heat pump system is 6.5% higher than that of the original R22 system, and the exhaust temperature in the low temperature environment is reduced by 36% to below 80 C.
A control strategy for battery/supercapacitor hybrid energy storage system
Authors: Xie Congzhen , Wang Jigang , Luo Bing , Li Xiaolin , Ja Lei
Published: November 2021

In DC microgrid (MG), the hybrid energy storage system (HESS) of battery and supercapacitor (SC) has the important function of buffering power impact, which comes from renewable energy sources (RES) and loads. This paper proposes a HESS control strategy with DC bus voltage self-recovery function. High and low frequency power decomposition based on virtual droop control, and DC bus drop voltage is compensated by added proportional integral regulation. The relationship between DC bus voltage recovery and super-capacitor (SC) state of charge (SoC) recovery is analyzed. The system can realize stable energy storage, supply under frequent load power impact. The effectiveness of the proposed control strategy is verified by simulation in MATLAB/Simulink.
A clock synchronization method in power dispatching based on BeiDou navigation system
Authors: Lian Hongbo , Wang Xingcai , Zhang Shuo
Published: November 2021

This paper introduces the problems of poor signal condition of a single time source in time synchronization or error in time source switching in the power system. It adopts the two-clock mode timing scheme of BeiDou 2 synchronous satellite and GPS synchronous satellite to ensure the stable output of the main clock within a certain accuracy. The system takes full advantage of the field programmable gate array (FPGA) hardware method, aligns the internal clock lock signal with the input second pulse phase, and proposes an improved method for the problem of large clock synchronization deviation based on the network, which proves the effectiveness and superiority of the system to accurately output the pulse and provide reliable time synchronization for the power dispatching system.
Research status of thermal management of hydrogen energy proton exchange membrane fuel cell
Authors: Liu Jibao , Cui Huanyong , Gao Lei , Wang Jiangtao , Wang Meiyan , Li Fajia
Published: November 2021

The working principle and advantages of proton exchange membrane fuel cell using renewable energy hydrogen as fuel are introduced, the importance of fuel cell thermal management is emphasized, and the performance influencing factors, heat source and design requirements of proton exchange membrane fuel cell are summarized. According to the current research status of fuel cell related thermal management, the methods of simulation analysis of fuel cell with the help of mathematical model are summarized, and the existing problems and solutions of fuel cell heat dissipation and cold start are summarized.
Recent progress for different inertial confinement fusion schemes: a systematical review
Authors: Qian Yihong , Huang Botao
Published: November 2021

The pursuing of controlled fusion energy has been continuously developed for more than half a century. Inertial confinement fusion (ICF) is one of two major approaches to actualize controlled fusion. Here, we systematically reviewed several typical forms of ICF on the part of their physical principles and encountering technical barriers currently. Besides, some great simulation results of the implosion for each ICF scheme are shown, and the simulation algorithm of Vlasov-Fokker-Planck (VFP) is introduced. In addition, several instabilities in the fusion process are analyzed. These results offer a guideline for future ICF research.
Application of Step Motor Servo Control Technology in Integrated Thermal Management of Advanced Fighter System
Authors: Hu Mingliang , Yu Erjun , Yan Wen
Published: November 2021

The integrated thermal management of advanced fighter jets directly affects the combat performance of the aircraft. This paper develops a set of multi-cycle integrated thermal management control system, based on the stepper motor drive servo valve. The stepper motor control system is integrated in the aircraft Remote Execution Unit (REU). The controlled information, such as flow, pressure, temperature, is collected and combined through the Remote Interface Unit (RIU). Through the IEEE-1394 bus, feedback achieves deterministic transmission between control-action-response, and through inverse time protection, the high reliable power drive can be achieved. The open-loop vector micro-stepping driving strategy of the stepper motor is designed, simplifying software and hardware designs. The experimental results show that the strategy developed in this paper can better realize the characteristics of two-phase current sine wave, have better acceleration performance, improve the controllability of the opening and closing angle of the stepping motor servo valve, and satisfy the comprehensive thermal management of advanced fighters.
Effect of rapid thermal shock cycle on the thermomechanical reliability of 20Sn-80Pb solder bumps
Authors: Chen Shiqi , Gan Guisheng , Xu Qianzhu , Jiang Zhaoqi , Huang Tian , Liu Cong , Ma Peng
Published: November 2021

The influence of rapid thermal shock(RTS) cycles on 20Sn-80Pb solder bumps was studied. In the study, 20Sn-80Pb solder bumps were prepared by desktop nitrogen lead-free reflow soldering machine. The prepared 20Sn-80Pb solder bumps were used for RTS test in the temperature rang of 0°C ~ 150°C. One cycle of RTS is 24 seconds, and the temperature rise and fall rate of RTS is 12.5 C/s. The result indicated that when the cycle of RTS reached 1500T (here T is cycle, the same below), the shear strength of Sn-80Pb solder bump dropped by drastically 48.6%. Whereas, when the cycle of RTS reached 5500T, 20Sn-80Pb solder bumps’ shear strength decreased to 18.35 MPa, which increased by 7.5% compared with that of l6.97 MPa at 4500T. With the increase of RTS cycles, 20Sn-80Pb solder bumps’ shear strength was a decreasing trend and the fracture mechanism changed from ductile fracture to ductile-brittle mixed fracture, which could be subject to the thickening of the interfaical IMCs and the stress concentration caused by the growth of interfacial IMCs. To understand the changes of the mechanical properties of 20Sn-80Pb solder bumps, the influences of RTS on the crack and interfacial IMC of 20Sn-80Pb solder bumps were studied in details.
Analysis and Prevention of Boiler fire-extinguishing Caused b y the Thermal DCS Fault
Authors: Zhao Mingliang , Guo Shuai , Song Zhiyu , Liu Xiu , Guo Ping
Published: November 2021

The number 4 boiler of a certain power plant happened the boiler fire extinction events. Because of main and auxiliary DPU switched failure, more piece of card took off the network and malfunctioned, both of PAF(Primary Air Fan) stop, which triggered MFT, that lead to the boiler fire-extinguishing. Aimed at the course of the boiler fire-extinguishing and the measure that had been adopted, this paper expounds in detail, analyzes the cause of the incident and other aspects of the problem that the incident exposed to, finally, in view of the existing problems and potential sa1fety hazard, this paper gives specific recommendations.
Crustal Structure Study in Lampung Region Using Teleseismic Receiver Function Analysis
Authors: Puhi A R , Ariyanto P , Pranata B , Prayitno B S
Published: November 2021

Lampung region is seismically and volcanic active because located in subduction zone of Indo-Australian and Eurasian plate. We applied receiver function and stacking H-k analysis to estimate the crustal structure in Lampung region. We used teleseismic earthquake data (epicenter distance 30°-90°) and M>6 recorded at 3 seismic broadband stations owned by Agency for Meteorology Climatology and Geophysics (BMKG). Those stations are PSLI (located on Sebesi Island approximately 20 km from Anak Krakatau) represented volcanic arc zone, KASI (located on Kota Agung, Lampung) represented Sumatran Fault Zone and KLI (located on Kotabumi, Lampung) represented back-arc basin. Crustal thickness estimated at PSLI station 32-36 km, KASI station 36-40 km, and KLI station 30-36 km. Furthermore, in 3 stations P wave velocity estimated 4.1-11 km/s, S wave velocity 2.2-6.2 km/s, while vp/vs value estimated 1.7-2.05. We estimated Anak Krakatau volcano’s magma chamber beneath PSLI station in depth 16-30 km, Great Sumatran Fault structure in depth about 8-14 km beneath KASI station, and thick sediment layer about 4 km near surface beneath KLI station. This study result is expected to explain more detail crustal of Lampung region and can be useful for developing of BMKG’s seismic monitoring systems and other geophysical fields in future.
Comparison Study of Crustal Structure in Aceh Region based on Volcanic Arc System using Receiver Function Method
Authors: Mahardiana R I , Ariyanto P , Pranata B , Prayitno B S
Published: November 2021

Aceh region has a very complex crustal structure from the forearc ridge to the backarc basin. This study aims to determine the velocity model of P and S waves and the depth of Moho discontinuity. This research was conducted using teleseismic earthquake data (30°-90° from the station) with M>6 from four seismic stations belonging to the BMKG in Aceh region. The stations are qualified based on the volcanic arc system zone. Furthermore, the velocity model determined by result of forward modelling, while the depth of the Moho layer estimated by migrated receiver function from time domain to the depth domain. At station SNSI that represented the forearc ridge zone, the depth of Moho is ±28 km, at station TPTI represent the forearc basin is ±16 km, while at zone with higher topography, namely volcanic arc zone represented by station KCSI, the Moho depth was identified at ±38 km, and the backarc basin represented by station LASI with ±40 km depth of Moho. This variation occurs because the composition of the earth’s layers below the station is diverse also different topography for each station.
Geothermal Reservoir Identification in Way Ratai Area Based on Gravity Data Analysis
Authors: Sarkowi M , Wibowo R C , Karyanto
Published: November 2021

Gravity research in the Way Ratai geothermal prospect area was conducted to determine geothermal reservoirs, heat sources, and the structure of the geothermal reservoir. The research carried out includes 3D inversion modeling of gravity data. The Bouguer anomaly in the study area has 50 mGal to 120 mGal with low anomalies located in the southeast (Ketang and Kelagian), Northeast (Gedong Air, Sungai Langka, Gunung Betung) areas, and in the Pesawaran mountain area. The high anomaly is in Merawan – Hanuberak – Padang Cermin, Sumbersari and Kaliawi. The horizontal gravity gradient map analysis shows a pattern of fault structure trending northwest-southeast and southwest-northeast, according to the main fault structure in the area. 3D inversion modeling obtains a density distribution between 1.8 g/cc to 3g/cc with a low-density distribution in the south, Mount Pesawaran/Ratai, Gunung Betung, and Sidoharum. The location of the manifestation is 9 km southeast of the Mount Ratai/Pesawaran summit. The existence of geothermal reservoirs is estimated to be in the Lubuk Badak and Miwung Hills areas which are located between the peaks of Mount Ratai/Pesawaran and geothermal manifestations. This is supported by the low-density distribution in the area and the resistivity map from audio-magnetotelluric data.
Getting to Know the Last Five Years Trend on Microcontroller Research: A Bibliometric Analysis
Authors: Yantidewi M , Jatmiko B , Sucahyo I , Kholiq A , Lestari N A , Deta U A
Published: November 2021

A microcontroller is a compressed microcomputer manufactured to control embedded systems in office machines, robots, home appliances, motor vehicles, and several other gadgets. This device has played significant and essential roles in daily human life. Unfortunately, an in-depth analysis related to microcontrollers has not been found. Hence, it is compulsory to conduct a comprehensive analysis to understand better the research themes and trends in a specific scientific scope. This study aims to determine the extent of the research development on microcontrollers carried out throughout 2017-2021 through bibliometric analysis. From the bibliometric analysis that has been performed, we can conclude that research on microcontrollers is dominated by sensors, algorithms, voltage, and power. On the other hand, research that shows the relationship between solar panels and microcontrollers is still lacking. With this finding, it is hoped that researchers will focus their research on potential topics that are rarely looked at.
Radiation Profile of 2.45 GHz Bi-Circular Loop Antenna using Parabolic Reflector Made of Frying Pan (Wajanbolic)
Authors: Annovasho J , Rahayu V , Ardimas A , Firdaus R A
Published: November 2021

This study aims to determine the dimensions of the antenna and reflector which can optimally work at a frequency of 2.45 GHz. A good antenna is an antenna that has high directive capability, high performance, and inexpensive. In this work, the proposed antenna model was a Bi-Circular Loop (BCL) with a reflector using a frying pan (Wajanbolic). The methods were used in this research for instance computational simulation, fabrication, and characterization. Simulations were carried out using the Finite Different Time Domain (FDTD) technique. The simulation results were compared with the measurement process. In the first simulation, four reflectors sizes could qualify as antennas, namely diameters of 309.00 mm, 335.00 mm, 364.00 mm, and 381.00 mm. The four reflectors sizes were optimized by changing the radius parameter of the BCL antenna. The best results were obtained on the reflector with a diameter of 364.00 mm and a BCL radius of 17.38 mm. The simulation results showed a radiation profile consisting of an RL value of -35.69 dB and a gain value of 16.40 dBi. Based on the fabrication and measurement of the antenna, the RL value was -54.75 dB and the directional antenna gain was 16.00 dBi. An antenna with such performance can be used as a point-to-point Wi-Fi transmitter.
Determination of Resonance Parameters of The PANI Thin Film Fabricated using Spin Coating Method
Authors: Putri N P , Al Azis F , Kamasi D D , Sakti S P
Published: November 2021

This study aims to determine the resonance parameters of polyaniline thin films to better understand the viscoelasticity properties of polyaniline films. The spin coating method was used with varying solvent concentrations and rotating speed of spin coater during the deposition Polyaniline (PANI) thin film on a quartz crystal microbalance (QCM). To determine the resonance parameters of the PANI thin film, the impedance and QCM frequency measurements were first carried out before and after coated with PANI. The modelling used is a modified BVD model, and the determined resonance parameters are C0, C1, L1, R1, L2 and R2. From the results of the analysis using the GRG Nonlinear solver program, it was found that solution concentration and rotational speed in the spin coating process has a significant effect on resonator parameters of PANI thin film. The best solution concentration from this study was 2% DMF with a rotational speed of 2,000 rpm. This is because in these conditions it provides a minimal damping effect on QCM.