bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Energy System Evaluation Method Based on Minimum Cross-Entropy and Prospect Theory
Authors: Wang Yongli , Yuan Bo , Teng Yue , Wang Yinuo , Liu Hang , Wen Ming
Published: February 2023

An integrated energy system can improve the reliability and flexibility of the energy supply, and has good economic and environmental benefits. Integrated energy system evaluation is of great significance to the implementation of an integrated energy system project. The integrated energy system evaluation method is presented based on the minimum cross-entropy model and the prospect theory. Firstly, the minimum cross-entropy model is used to obtain the comprehensive column vector of each evaluation index. Secondly, the index weight is determined according to the different weight methods. Finally, through the establishment of positive and negative prospect value matrices, according to the comprehensive prospect value, the advantages and disadvantages of integrated energy system schemes are sorted. The effectiveness of the proposed method is verified by hotel-integrated energy system data.
MIM Waveguide Coupled Resonator Sensing System in the Background of New Energy
Authors: Liu Jilai , Zhang Xiaoyu , Shen Lifang , Zhu Chuanhui , Yan Shubin
Published: February 2023

In this article, we design a MIM waveguide-coupled resonator system. This resonant cavity has a semicircular ring cavity with the square cavity (SRSC). The effect of that Fano phenomenon on this sensing property on this system is explained in detail by using the finite different time domain method and finite element analysis method. This sensor was analyzed by COMSOL Multiphysics 5.4a simulation software to explore the influences of the structural arguments to the sensitivity. After structure optimization, a sensitivity of the sensor can reach 1640 nm/RIU, and the figure of merit (FOM) of this system is 41. This has great application prospects in the field of integrated optical circuits and biosensing.
Research on Gamma Spectroscopy System While Drilling Based on DSP and FPGA
Authors: Zhang Jianfeng , Yang Zhen , Li Yonghua
Published: February 2023

The traditional gamma energy spectrum measurement system performs filtering, shaping, amplification, baseline recovery, stacking discrimination, peak hold, and low-speed ADC sampling on the pulse signal output by the gamma-ray detector. It generates energy spectrum curves. There are problems such as large dead time and pulse signal accumulation. A high-speed digital processing chip (FPGA) and a high-speed ADC are used to perform full pulse sampling on the amplified ray pulses directly. The high-speed digital processing chip (DSP) directly realizes the pulse signal recognition, which remarkably improves the efficiency of signal acquisition and is very suitable for developing the drill gamma spectroscopy system. Scholars have studied the pulse digital Gaussian shaping algorithm and the trapezoidal shaping algorithm in gamma-spectroscopy while drilling to explore this phenomenon. In this case, a gamma-ray spectrum measurement while drilling system based on DSP and FPGA is designed. It realizes the functions of full-pulse high-speed sampling and energy spectrum curve generation for the narrow pulse signal input to the detector. It also converts the energy spectrum curve. It is transmitted to the host computer through the serial port for energy spectrum analysis.
Study on Calculating Method of the Super-transient Reactance of Permanent Magnet Motor and Analysis of Influencing Factors
Authors: Shi Bin , Guo Yujing
Published: February 2023

This paper takes a salient pole permanent magnet wind generator as the research object and summarizes the calculation method of its super-transient reactance parameters. The analytical method and parameter identification method are selected to analyze the influencing factors of the direct axis super-transient reactance parameters. Finally, the variation law of direct axis super-transient reactance parameters with the number of parallel branches, short pitch ratio, and diameter of damping windings is obtained, which provides a certain reference for the dynamic performance evaluation of permanent magnet motors.
Analysis of the Influence of Distributed Generation on Distribution Network Voltage
Authors: Zhang Xiuqi , Guo Kai , Wang Liqiang , Cong Yu , Wang Qi
Published: February 2023

This paper introduces the development and application background of distributed generation and analyzes its technical characteristics. According to the relationship between distributed generation and traditional distribution networks, the models of different types of distributed generation are equivalent to PQ, PI, PV, and PQ (V) nodes. Besides, this paper analyzes the impact of distributed generation on the voltage of the distribution network from the perspective of position and capacity. It points out the direction for further research.
Study on the method of detecting oil pipeline clogging by fluid oscillation theory
Authors: Zhu Sha , Xu Ying , Zu Chunyang , Li Yuexiang , Yu Zifeng
Published: February 2023

In order to solve the problem of pipeline clogging detection, a mathematical model of pipeline clogging detection is established by applying fluid oscillation theory. The amplitude of each component harmonic in different periods is expressed by Fourier series, and then the clogging attenuation parameters of each harmonic are obtained. According to the ratio of harmonic of two separate components and the plugging attenuation parameter, the plugging position and magnitude are determined respectively. Through the analysis of numerical simulation and experimental results, it can be concluded that the method of using fluid oscillation theory to detect pipeline blockage is correct.
Experimental study of static wind force on typical substation post disconnect switchgear three-post structure under different wind angles
Authors: Li Peng , Liu Sikai , Liu Huibin , Cheng Yongfeng , Liu Bin , Gao Chunhui , Zhang Xinwei , Liang Jiayu , Huang Huaizhong , Liu Qian
Published: February 2023

As a wind load-sensitive structure, the wind characteristics of typical post-disconnect switchgear in substations are of great significance to the design of the wind resistance of the structure. To study the static wind characteristics of the three-post structure of post-disconnect switchgear, this paper conducts high-frequency force balance (HFFB) wind tunnel tests on the three-post model of post-disconnect switchgear and obtains information on the variation law of the static wind force coefficient of the model with the wind angle and the most unfavorable wind angle. The results show that the model drag coefficient, combined force coefficient, and skewed wind load factor are M-shaped and symmetric at about 90° under different wind angles, and the most unfavorable wind angles are 60° and 120°; the lift coefficient and torsional moment coefficient are antisymmetric about 0°, and the overall values are small. In general, the model is mainly subjected to along-wind static wind force, and the static wind force distribution is influenced by the skewed wind and changes uniformly. The model mainly produces a bending effect under the action of static wind force, and the torsion effect is not obvious.
Research on accurate thermal network calculation model of modular permanent magnet motor
Authors: Guo Yujing , Xu Ruihai , Liu Xipeng
Published: February 2023

This paper proposes a thermal network model for calculating the modular permanent magnet motor’s temperature rise. Analyzing the actual heat flow path of motor Joule loss and considering the circumferential heat conduction of winding, the local three-dimensional thermal network model of winding is constructed. Based on the model, the motor parts’ steady and dynamic temperature rise is calculated and verified by the FEM. The thermal network model also applies to motors with short winding ends and complex stator yokes.
Multi-objective Optimization Method for Hybrid Energy Storage Capacity of Wind Farm Based on Source-load Interaction
Authors: Li Wenwei , Zhu Long
Published: February 2023

The traditional method for multi-objective optimization of a wind farm’s hybrid energy storage capacity does not fully consider the impact of source-load interaction on wind power consumption capacity, resulting in a high total system operation cost. Therefore, a multi-objective optimization method for the hybrid energy storage capacity of the wind farm based on source-load interaction is proposed. According to the topological structure of the system, a multi-objective optimization model is constructed. The constraint conditions of the optimization model are studied. By synthesizing the constraint conditions, multiple objective functions are aggregated into a single objective function. The model is solved by using the ordinal optimization theory to get the optimal solution of the objective function. The experimental demonstration adopted the proposed method to improve the wind power system’s energy storage capacity. The results show that the operation cost of the system is lower after the proposed method is adopted to improve the wind farm’s hybrid energy storage capacity. Therefore, it can be proved that the total operation cost of the system can be decreased by integrating the interactive load into the hybrid energy storage optimization’s wind farm capacity.
Research on Power-Frequency Overvoltages of 220 kV Offshore Cable Transmission System in Liaoning Province
Authors: Duan Wei , Gu Borui , Kong Minru , Li Han , Pu Lu , Zhao Xuefeng , Ju Zeli
Published: February 2023

Since power-frequency overvoltages can influence the safe operation of the submarine cable transmission system greatly, it is indispensable to calculate the overvoltages that may occur during actual situations. In this study, the power-frequency overvoltages of the offshore oil-gas field group’s submarine cable transmission system are calculated through PSCAD/EMTDC. Among the different conditions considered, the maximum power-frequency overvoltage is 1.134p.u., which occurs in the case of single-phase fault earthing at the cable joint in L4. The result fulfills the limit of relevant regulations for the 220 kV transmission system, indicating that the submarine cable transmission system can operate safely and effectively, which can provide important guiding significance for the construction and operation of the system.
Net Power Prediction for High Permeability Distributed Photovoltaic Integration System
Authors: Cao Huafeng , Yang Liu , Li Hu , Wang Kun
Published: February 2023

The large-scale grid-connected access to distributed PV power generation has posed a great challenge to the new power system. Distributed PV power output and power load have strong uncertainty and volatility, which increases the difficulty of distribution network net power prediction to a certain extent. To improve the prediction accuracy of distribution grid net power, the paper proposes a combined distribution grid net power prediction method based on XGBoost and RBF neural networks. The combination of the two neural network algorithms into the power prediction model makes up for the lack of learning ability of the single neural network model for the input features of net load prediction, and can greatly improve the generalization ability and prediction accuracy of the model. The experimental results show that the described method improves the net power prediction accuracy of the distribution network and outperforms the comparison model.
Resilience enhancement strategy of multi-energy coupling distribution network considering movable energy storage equipment
Authors: Dou Zhenlan , Zhang Chunyan , Dai Renjie , Wei Siming , Zhang Jihang , Wang Lingling , Jiang Chuanwen
Published: February 2023

With the deepening of energy transformation, multi-energy coupling has become an effective method to alleviate the energy gap and improve the energy utilization rate. As a bridge connecting users and the power system, the distribution network is becoming multi-energy coupling as well. Therefore, to ensure a stable supply of power, heat, and other energy sources, it is of great significance to study the resilience improvement of multi-energy coupling distribution networks. This paper proposes a strategy for improving the resilience of multi-energy coupling distribution networks considering movable energy storage equipment (MESS) configuration. Firstly, the multi-energy coupling distribution network model is established, and the mathematical model of each piece of equipment is established considering the coupling of the power grid and heat grid. Secondly, based on the loss of load probability (LOLP), considering the importance of the load, it is expanded to the loss of important load probability as an index to evaluate the resilience of distribution networks. Thirdly, a distribution network resilience improvement model based on the configuration and operation of the MESS is established, and the optimal configuration capacity and operation strategy of the MESS is solved by taking the minimum operation cost as the objective function, i.e., the configuration cost of the MESS, the load shedding cost and the cost of wind and PV abandonment. Finally, based on the IEEE-33 node distribution network, a multi-energy coupling distribution network model is built, which verifies that the method proposed in this paper can effectively reduce the total cost and improve the resilience of the multi-energy coupling distribution network.
Tuned Mass Damper Design of Substation Post Switchgear in Gale Area
Authors: Cheng Yongfeng , Huang Huaizhong , Li Peng , Gao Chunhui , Liu Huibin , Liu Bin , Liang Jiayu , Liu Qian , Liu Sikai
Published: February 2023

Post switchgear of substation in a gale area is a typical wind-sensitive structure. In order to reduce the wind-induced response of substation post switchgear in a gale area, in this paper, according to the theoretical formula of the optimal frequency ratio and the optimal damping ratio of TMD given by Den Hartog, a tuned mass damper (TMD) is proposed to reduce the vibration of the first-order vibration mode outside the plane of the structure. The Simulink simulation model of the simplified structure with TMD is established and the fluctuating wind speed of the equipment is simulated by the Kaimal wind speed spectrum. The wind vibration control effect of TMD is checked, and the rationality of the TMD design is verified.
Analysis of the Impact of Carbon Emission Trading Mechanism on the Electricity Market under Dual Carbon Targets
Authors: Guiyuan Xue , Yin Wu , Wenjuan Niu , Chen Chen , Xiaojun Zhu , Jian Tan
Published: February 2023

To achieve the goals of sustainable development and energy conservation and emission reduction, a model is constructed through system dynamics to explain the mechanism of the carbon emissions trading system and analyze the impact of the carbon emissions trading system on China’s electric power based on analyzing the relationship between the carbon market and the electricity market. The role of the market and the simulation of its policy effects it. The results show that the carbon emissions trading system has an impact on the on-grid electricity price, the installed capacity of renewable energy, and the installed capacity of thermal power generation in China’s power market. The establishment of a reasonable carbon emissions trading mechanism will have a positive impact on the development of China’s electricity market, which plays a long-term and effective role.
A Framework Design to Improve the Operation Capability of Cyber Security for Electric Power Dispatching and Control Systems based on the Concept of SOC
Authors: Li Xiaomeng , Zhao Jingcheng , Cao Yaofu , Liu Junwen , Yan Junlu , Li Huimin
Published: February 2023

Benefiting from the vision of the Security Operation Center (SOC), this paper proposes a construction plan for a cyber security operation center for the electric power dispatching and control system. This solution integrates and analyzes various data such as ledger database, knowledge database, and historical alarm database in the power dispatching and control system, and realizes the functions of alarm handling, risk assessment, and emergency response for the existing security management platform. Through the risk evaluation experiment, it is verified that our scheme has the function of overall interacted active security defense, and can effectively improve the cyber security risk resistance of the power dispatching and control system.
High-precision Positioning Method for BD3 System Based on Adaptive Optimization
Authors: Yu Zhiwen , Chen Zhiwei , Zheng Wenjie , Zhao Ruifeng , Xu Zhanqiang
Published: February 2023

It is of great significance to locate faults quickly and accurately in power distribution system to improve system reliability and recover quickly. With high positioning accuracy, strong anti-interference ability in mountainous areas and cities, and the ability to provide all-weather and all-round services, the BeiDou-3 (BD3) navigation satellite system has broad application prospects in power systems. Using the filtering principle of normalized least mean square (NLMS) filter, a high-precision positioning method for BD3 system based on adaptive optimization is propose to eliminate the pseudo-range error caused by electromagnetic interference. Simulation results show that NLMS-based adaptive pseudo-range filtering method can availably decrease the pseudo-range error caused by high proportional electromagnetic interference in the power system, achieve adaptive optimization of power system device positioning, and improve positioning accuracy.
Circuit Breaker Identification Based on SSD
Authors: Li Yuhuan , Yang Fan , Li Yan , Tan Changshu , Liu Zijun
Published: February 2023

The circuit breaker is a device that cuts off and connects the load circuit in the power system, cuts off the fault circuit, prevents the accident from expanding, and ensures safe operation. Detecting circuit breaker failures is necessary to ensure power systems’ safety. Before fault identification, the circuit breaker must be identified and positioned first. In this paper, a circuit breaker identification technology based on SSD is adopted, and SSD is used to identify the circuit breaker and mark the voltage name quickly.
The strategy of VSG rotational inertia adaptive inverter dual-output seamless shore power connection
Authors: Fan Huaigu , Xiao Leming , He Yumin , Yang Hewu
Published: February 2023

This paper introduces the seamless power supply of the inverter dual output virtual synchronous generator(VSG) model based on the characteristics of ship generator grid connection and transfer load. By establishing VSG mathematical model, it introduces the advantages and deficiencies of VSG adaptive control of inertia (ACI), and the improved adaptive control of inertia(IACI) is proposed. Then, the setting method of VSG frequency tracking coefficient, rotational inertia and other parameters is given. Finally, we provide experimental proof for the ACI and IACI control effects.
Dynamic Equivalent Software Design for AC/DC Hybrid Power System
Authors: Huang Guanbiao , Su Yinsheng , Wang Changxiang , Zhao Ligang , Zhou Tinghui , Zhen Hongyue , Xu Yuan , Mao Zhenyu , Tu Sijia
Published: February 2023

This paper proposes a new software design method of dynamic equivalents for the AC/DC hybrid power system. First, some critical issues of dynamic equivalents for the AC/DC hybrid power grid have been intensively investigated. Then, in consideration of the function requirements, this paper builds a general framework for the dynamic equivalent software, which follows the design routine of the separateness of modules and data switching, and flexible extensibility. Finally, a new software tool for dynamic equivalents is developed with OOP technics and unified modelling, and a case has been studied to validate the performance of the newly developed software.
A Model Predictive Control Method for Efficiency Optimization of Permanent Magnet Synchronous Motors
Authors: Wang Tianyi , Li Haitao , Zhang Zhenbin
Published: February 2023

As one of the important forms of AC motors, permanent magnet synchronous motors (PMSM) are widely used in wind power generation systems, new energy vehicles, and other fields. To improve the operating efficiency of PMSM, a new model predictive control method considering controllable losses is proposed. After building the PMSM loss model, an accurate variable prediction method is derived. By incorporating the controllable loss prediction value into the cost function, the system operation efficiency is dynamically improved. Moreover, this method configures a weight coefficient for the loss penalty term, to obtain a trade-off between efficiency and transient time. The simulation results show that the efficiency, stator current THD, and MTPA capability of the proposed method are superior to the traditional model predictive control method.
An N-1 security analysis method of distribution network based on minimum isolation area information matrix
Authors: Gao Lingjun , He Huaqin , Wu Canxiong , Zeng Weiwei , Chen Yaodong , Zhang Wei
Published: February 2023

To solve the problem of fast online analysis of distribution network operation safety, an N-1 security analysis method of distribution network based on minimum isolation area information matrix is proposed. Firstly, the minimum isolation area information matrix model is established to describe the switch and distribution transformer information in the minimum isolation area of all feeders in the distribution network. Then the real-time load information matrix of the minimum isolation area is used to determine the total load to be transferred downstream of the fault. Secondly, the active power margin of the switch in the load transfer path is described by the load transfer path switch information matrix and the switch capacity information matrix. Finally, the recoverable power supply downstream of the fault area is analyzed by comparing the minimum margin information matrix and the total transfer load. This method can quickly realize the N-1 safety analysis of the distribution network and identify the minimum isolation areas and weak links that do not meet N-1. It can meet the needs of on-site, real-time online calculation and analysis.
Distributed state estimation method of distribution networks based on LSTM
Authors: Jiang Sicheng , Yang Shuhang
Published: February 2023

In this paper, long-short-term memory (LSTM) is introduced into the distributed state estimation (DSE) method, and the state prediction value obtained by LSTM is used as the new measurement in each sub-area. The state prediction value obtained by LSTM is used as a sign to judge whether the measurement in each sub-area at the current time is abnormal, which avoids unnecessary bad data detection when the measurement is normal. Through the simulation of IEEE33 bus distribution network system, it is verified that the proposed method can effectively identify bad data and has high computational efficiency.
Application Analysis of Low-voltage Storage and Charging Integration Cabinets in the Pilot Program of Guesthouse in Zhangjiajie City
Authors: Liu Kai , Nie Bin , Zhuo Jiaquan
Published: February 2023

Based on a guesthouse in Zhangjiajie as an example, this paper carried out the installation, design, and pilot construction of low-voltage storage and charging integration cabinets to construct the new courts-level power system. In doing so, it also analyzed the regulating effect and efficiency measurement of integrated energy storage systems in the new low-voltage and courts-level power system during the sharp, peak, shoulder, and off-peak periods of the guesthouse, so as to provide a reference for more innovative practices and application of the storage and charging cabinets, and put forward the commercial promotion mode of these cabinets suitable for guesthouses in Zhangjiajie.
Comparing Explicit and Implicit Methods for Estimating the Region of Attraction
Authors: Yuan Guoqiang , Li Yinghui , Xu Haojun , Xu Jihui , Gao Jianguo
Published: February 2023

The region of attraction (ROA) is an important tool in investigating control and dynamic systems. Numerous computational methods have been proposed for estimating the ROA within the Mathematics, Power systems, and Control community. These methods employ different methods such as invariant manifolds, linear differential inclusion, level set methods, the sum of squares decomposition, and many others. This paper provides new insights into these methods and divides them into two classes: explicit and implicit. The explicit methods discretize the ROA (or the boundary of the ROA) into a finite union of geometric elements and store them directly. The essential idea of the implicit methods is to present the ROA implicitly, meaning that it is feasible to find the ROA as the level set of some function of the state space variables. The key point is the iteration and optimization of this implicit function. The explicit and implicit methods are compared and discussed by investigating some numerical examples. In particular, we consider the determination of the boundary of the ROA using the stable manifolds, and the estimation of the ROA as backward reachable sets using a Hamilton-Jacobi-Isaacs partial differential equation.
Study on SOC Estimation of Li-ion Battery Based on the Comparison of UKF Algorithm and AUKF Algorithm
Authors: Guo Yi , Chen Yuhang
Published: February 2023

In this study, a state of charge (SOC) estimate technique for lithium-ion batteries is presented using an adaptive traceless Kalman filter (AUKF). First, the battery’s second-order RC equivalent circuit model is created, and its parameters are identified. Next, in contrast to the traceless Kalman filter (UKF) algorithm, which ignores the time-varying characteristics of the system noise when estimating the lithium-ion battery’s state of charge, the AUKF-based SOC estimation method is formed from the perspective of adaptive noise adjustment (SOC). The results of testing the AUKF algorithm in real-world settings demonstrate that it has great estimate accuracy and stability and that its estimation outcomes outperform those of the UKF method.
Short-term Wind Speed Prediction Based on Improved Auto Encoder
Authors: Yin Yikun , Shang Zengyi , Li Fengxia , Shao Hailin
Published: February 2023

In order to improve the wind power consumption level of the new power system with new energy as the main body, it is necessary to accurately predict the wind speed. The key is to refine the dynamic trend of the wind power system and the potential physical structure in the wind speed sequence. Firstly, on the basis of the library Koopman dynamics theory and the encoder structures, a physically constrained spatio-temporal neural network is built, which generates the linear evolution moment of the nonlinear variables of the wind farm. Secondly, the system trend is approximated by the linear evolution matrix, and the forward and backward dynamics are fully considered in the prediction process. Then, the bidirectional correlation prediction mechanism and the cost function adapted to different objects are set to reduce the requirements for the reversibility and stability of the prediction sequence. Meanwhile, the hidden vector of feature space is visualized to show the feature interval dependency in the system. Finally, the effectiveness of the proposed method is verified by the wind speed measurement data of Prince Mountain in Beipiao. The results show that the proposed method has high prediction accuracy, strong generalization ability, and high interpretability for strong random and strong fluctuation wind speed series.
Open capacity calculation method of distribution network
Authors: Li Jianyu , Wang Jie , Lin Yujie , Yang Binhao , Wu Chengjian
Published: February 2023

At present, there are few methods for quantitative calculation of installed load or new energy for distribution network equipment. Based on this, this paper proposes a calculation method for the open capacity of the distribution network. Firstly, the calculation methods of the open capacity of a 10 kV distribution transformer, 10 kV lines, and high-voltage substation three-level distribution network based on the conventional situation and new power system are studied, respectively. Then the calculation methods of the open capacity of the distribution system based on the conventional case and the new power system are studied, respectively. Finally, the empirical region is selected, and the research results are used for case analysis to verify the effectiveness and operability of the research results.
Research on fault reconstruction of ship regional distribution System based on improved genetic algorithm
Authors: Long Qiannan , Shi Weifeng
Published: February 2023

To ensure that the power supply can be restored quickly when the ship’s power system fails, the fault reconstruction method of the system is studied. Taking the number of switching operations and load loss as the objective function, the traditional genetic algorithm is improved by introducing a Tent population initialization, adaptive crossover probability, and mutation probability to realize the fault reconstruction of the ship regional distribution system. Two reconstruction examples show that the improved genetic algorithm can effectively solve the reconstruction problem of the ship’s regional distribution power system, and has good convergence speed and accuracy, which can ensure the stable operation of the ship power system.
Non-intrusive Load Identification Algorithm Based on Stacking Modeling
Authors: Miao Weiwei , Zeng Zeng , Teng Changzhi , Zhang Rui , Li Shihao , Bi Sibo , Wang Jijun , Zhou Haocheng , Li Fubao , Zhang Yongze
Published: February 2023

The non-intrusive power load identification relies on the smart meter’s voltage, current and power signals, which can realize the classification and monitoring of the domestic electric load. The load identification algorithm is the core of the system. Non-intrusive power load intelligent identification systems are generally based on a single model for aggregation, and commonly used models include hidden Markov models, graphical models and deep learning models. Usually, a single model is only effective in identifying certain types of electrical loads, and its universality and generality need to be improved. Improving the decomposition accuracy of the model is the main purpose of implementing non-intrusive powerload monitoring. The stacking integration algorithm is used to optimize the non-intrusive powerload monitoring model. The stacking integration model is divided into two layers. The base model initially decomposes the load and realizes the load accuracy through the meta-model. Experiment results show that the non-intrusive load identification algorithm based on Stacking modeling proposed in this paper can accurately decompose the minute-level sampled data. Compared to a single model, the decomposition accuracy of this method is improved by 8.2%.
Prediction for Tokamak High-power Pulse Load based on Elman Neural Network
Authors: Wang Junjia , Chen Hui , Hu Hejun , Huang Yiyun
Published: February 2023

A dynamic load prediction model of the Elman neural network is suggested to increase the reliability of the tokamak high-power pulse prediction. The method enhances the network’s capacity to process dynamic input by employing a dynamic back-propagation algorithm. A comparison of the simulation prediction results and measured data, depending on the measured data of the EAST (the experimental advanced superconducting tokamak) power bus, shows that the prediction results of Elman are more accurate than the traditional BP neural network, which can describe the impact of the fusion device’s pulsed load on the power grid better and increase the precision of stability analysis.
Comparison of SAGA and GA in Wind Turbine Layout Optimization Based on Modified Two-dimensional Wake Model or Jensen Model
Authors: Yang Wanqing
Published: February 2023

In this paper, Simulated Annealing Genetic Algorithm (SAGA) and a new two-dimensional wake model called 2D_k Jensen model are adopted for optimal wind turbine layout (WTL) in the wind farms and are compared with Genetic Algorithm (GA) and Jensen model, respectively, aiming to minimize the investment cost and maximize the wind power generation as much as possible. The influence of the radial distribution of wake on the equivalent wind speed in the wake superposition region is considered. In the case of single wind direction and single speed, total output power and energy extraction efficiency are both improved when SAGA is applied to the two model conditions respectively, especially for the WTL using the 2D_k Jensen model, these two aspects are significantly improved by 13.75% and 24.10%, respectively, and the objective function is reduced by 19.05%. The results demonstrate that SAGA is more conducive to solving the practical configuration optimization of wind turbines, compared with the original GA.
Research on adaptive active power coordinated control strategy of Zhangbei Flexible DC Grid project
Authors: Song Yantao , Zhong Qidi , Xiao Kun , Gao Zijian , Wu Qingfan , Song Wei
Published: February 2023

Zhangbei Flexible DC Grid project with grid characteristics is different from the previous multi-terminal flexible DC project. Zhangbei Flexible DC Grid project uses a DC breaker (DCB) to isolate DC line faults. Limited by the current domestic research and development level of high-voltage DCB, it does not have overload operation capacity. Against this problem that the overload of DCB endangers the safety of equipment and system after a permanent fault of the DC overhead line, the adaptive power coordination control strategy is proposed when the sending end converter station is connected to the new energy station and the AC grid respectively, The feasibility and rationality of this strategy are verified by the RTDS real-time simulation system of Zhangbei Flexible DC Grid project and provides technical reference for the long-term upgrading and transformation of Zhangbei Flexible DC Grid project.
Optimizing direct normal irradiance prediction of BP neural network based on Logistic Sparrow search algorithm
Authors: Lu Jun , Bai Wangwang , Feng Zhihui , Cai Ping , Chen Baoqi
Published: February 2023

With the wide application of photothermal power stations in power systems, Direct Normal Irradiance(DNI) prediction is very important to improve the economic benefits of photothermal power stations and the utilization of solar energy. The short-term prediction of wind power by traditional Sparrow search algorithm (SSA) optimized BP(SSA-BP) neural network is prone to fall into local optimum, slow convergence rate, and low prediction accuracy. A short-term DNI prediction method based on the Logistic Sparrow search algorithm (Logistic-SSA) optimized BP(Logistic-SSA-BP) neural network is proposed. This paper takes a photothermal power station in Northwest China as the research object. Firstly, the Pearson correlation coefficient is introduced to analyze the environmental data set with a strong correlation with the direct illumination radiation index as the input of the model, so as to avoid redundant data affecting the prediction of the direct illumination radiation index. Secondly, the SSA algorithm and Logistic-SSA algorithm are used to improve BP neural network. Finally, the measured historical data of the photothermal power station is used to simulate the prediction models. The simulation results show that the prediction model based on Logistic-SSA-BP has better prediction accuracy than SSA-BP, and is more in line with the production and operation requirements of the photothermal power station.
A Substation Live Detection Method on Communication Protocol Data Parsing and Data-level Fusion of Neural Networks
Authors: Zhang Yanyan , Ning Xuefeng , Li Long , Chen Yunan , Xi He , Wang Shaorong
Published: February 2023

In this paper, a data parsing method based on database communication protocol technology and a data fusion method based on the neural network are proposed, which solves the shortcomings in the data communication process of the substation, and provides an intelligent method for data analysis and fusion. The data parsing, transforming method, process, and implementation scheme based on the communication protocol is described in this paper. Firstly, the digital expression method of the data message is proposed. Secondly, the message recognition method based on the feature field is introduced. Through the analysis and heuristic of the feature fields, the protocols of the messages are determined. then the data interface relationships in the system are stored in a separate database. When the parsing process is completed, we use data pre-processing, data cleaning, data integration, and other methods to fuse the data of each source. Finally, the unstructured data fusion method based on the VGG-19 model is used to fuse the data. At the same time, this paper also describes the scheme of some principles step by step and introduces the relevant technical details.
Research on Power Grid Short-term Load Forecasting Method Based on Data Mining
Authors: Bi Yanbing , Su Yanlong , Yang Jun , Wang Yuling , Hu Yu , Pan Shitong
Published: February 2023

Because the abnormal location of the power grid load is mismarked, the average relative error increases in the process of forecasting. This paper proposes to study and analyze the method of short-term load forecasting based on data mining. It preprocesses the load characteristic clustering and related data, marks the abnormal position of a power grid within a calibrated mining range according to the load fluctuation state, and defines the short-term load forecasting range. It also constructs a data mining power load forecasting model through the acquired real-time forecasting data and information, designs layered and staged load forecasting links, and corrects and calculates by adopting data mining. The prediction residual error is obtained. The stage prediction standard is further determined, and the prediction processing is realized. The final test results show that the data mining short-term load forecasting test group designed in this paper has a small fluctuation range, indicating that the prediction error has been greatly controlled in the practical application process. The prediction error is small, the accuracy is improved, and it has practical application value.
A State-of-Charge estimation method of Lithium battery based on BP neural network
Authors: Wei Wang , Xiangdong Meng , Han Liu , Gang Li
Published: February 2023

In the proposal of Dual-Carbon plan and the rapid development of clean energy generation, the energy-storage has become an important development direction in the power field. In this paper, the key parameter of the lithium battery-based energy-storage system—SOC estimation method are studied, the second-order resistance-capacitance model of the lithium battery is analysed. The equivalent circuit model of the lithium battery is established. The calculation basis of SOC in lithium battery is determined. The SOC estimation method of the battery is realized by BP neural network. The availability and performance of the advanced method is proved by the simulation analysis results based on the public lithium battery data.
Optimization of a salt gradient solar pond for air heating application
Authors: Verma Sunirmit , Das Ranjan
Published: February 2023

In this study, it is demonstrated that when a solar pond is used for an air heating application like crop drying, domestic space heating, greenhouse heating etc., it is important to account for pumping power in the calculations. When air is the working fluid, the magnitudes of extraction and pumping power are comparable. Therefore, a new parameter is defined in context of solar ponds used for air heating, namely, effective power (defined as power extracted minus pumping power). At first, using a steady-state analysis, a closed form solution is derived for extraction power. The pertinent expression for pumping power is taken from the literature. Thus, an analytical expression for effective power is obtained and thereafter, an optimization analysis has been carried with the objective of maximizing this effective power. The analysis is used to calculate optimum values of air mass flow rate and pond’s non-convective zone thickness at which maximum effective power is registered. The corresponding maximum effective power and the associated air outlet temperature are also calculated. This work thus is believed to prove useful for designing of solar ponds that are used for air heating applications in a manner to ensure maximal system performance.
Analysis of axial windage loss in air gap of high-speed motors under high Taylor number
Authors: Song Yuchen , Cao Jiwei , Zhong Chengbao , Chen Jialiang , Li Liyi
Published: February 2023

In the field of ultra-high-speed motors, windage loss rises rapidly with the increase of rotational speed, and even becomes the main part of motor loss. However, most researches of windage loss are based on empirical formulas, which has a narrow scope of application. These formulas could not guarantee the accuracy when calculating large Taylor number flow in high-speed motor air gap, especially under axial ventilation condition. This paper focuses on the interaction between Taylor vortices and axial flow, analyses the influence of Taylor number on the behaviour of Taylor vortices and windage loss under non-axial and axial ventilation. First, another form of friction coefficient related to rotation speed is proposed using dimension analysis. Second, the scale of Taylor vortices is estimated and how it affects windage loss is discussed. Finally, a deceleration experiment taking a 250krpm induction motor is used to verify the accuracy of the proposed windage loss model.
Safety evaluation on devices of high-pressure hydrogen refueling stations
Authors: Shi Zhuoming , He Pengfei , Wang Benjin
Published: February 2023

Hydrogen refuelling stations are established in various places nowadays. With the development on the hydrogen refuelling under higher pressures, the risk of hydrogen leakage on the devices, specifically the compressor and the dispenser, draws increasing concerns for these stations. In this paper, different cases of hydrogen leakage and combustion are evaluated for these devices with respect to various conditions, based the prototypes designed for a high-pressure hydrogen refuelling station in China. The results show that the limited hydrogen flow in the compressor ensures that no serious accident will occur after leakage. As for the dispenser, the cases for internal leakage on the main tube and the external leakage on the nozzle hose are studied and compared. According to the results, the harmful and lethal distances are obtained. Also, the effect of wind speed on the gas diffusion field and the temperature field are quantified by the simulation. It can be stated that the severity of ignition will increase with consideration of the wind. The results can be beneficial to the timely detection of the possible hydrogen leakage of the devices, and to the optimized layouts for the design of stations.
An auxiliary design system for industrial heat supply system considering carbon reduction benefit
Authors: Ren Jiayi , Wang Fei , Fan Zikai , Han Siwei , Zheng Jiaqi
Published: February 2023

Decarbonization of industrial process heating plays a crucial role in China’s carbon neutrality strategy. Traditionally, industrial users make decision on heat supply system design based solely on economy, with little regard for carbon emission. This study proposes an auxiliary design system to help the designers choosing proper industrial heating supply scheme considering carbon reduction benefit. Through traversal the existing scheme database, all feasible solutions are screen out and then evaluated by calculating an proposed comprehensive economy evaluation index. The comprehensive economy evaluation index takes carbon reduction as revenue since industry users will be able to trade their carbon emission rights at the carbon markets though CCER programs in the future. Future carbon price given by the carbon price prediction module is used to calculate the revenue user can get from carbon reduction. Grid emission factor prediction module makes prediction for changing grid emission factor, which is also involved in the evaluation to consider the benefit from continuously increasing green power in the future. A case study is given with heating demand data of a food factory to shown that the proposed method can reflect the value of carbon reduction, which helps to promote low-carbon technologies in the future.
Research Progress of Electroplated Micropore for Interconnection Technology
Authors: Sun Zhaoning , He Guanghui , Zhao Zhenbo , He Xiao , Zhao Hao
Published: February 2023

Electroplated micropore interconnection is one of the core technologies to realize the electronic connections of the high-density multilayer Printed circuit board (PCB). The quality of electroplated copper layer is a key factor for the reliability of PCB and electronic components. Focusing on the acid copper plating process, this paper expounds the development of the electroplating solution and additives, the mechanisms of electroplated copper deposition and hole filling mechanism, and the process control of electroplating, which will provide a reference for the in-depth study of the electroplating micropore interconnection technology.
Modification and performance evaluation of Konjac gum in drilling fluid
Authors: Shan Hou
Published: February 2023

Because of the rock carrying property of drilling fluid, it is usually necessary to add bentonite and polymer into the drilling fluid to improve the viscosity of the drilling fluid. However, bentonite and polymer will seriously affect the rheological property, sand carrying property, drilling speed, degassing effect, etc. of the drilling fluid. Therefore, it is necessary to develop a new environment-friendly low viscosity cutting agent for drilling fluid. In this paper, konjac gum was modified by metal complexation. Some modified konjac gum were studied. The effects of different dosages of modified konjac gum on the rheological properties of drilling fluid were analyzed through infrared spectrum characterization, thermogravimetric analysis and compatibility evaluation. The experiment proved that heavy metal cations and inorganic flocculant polyaluminum chloride/iron can coordinate with konjac gum, to form a cation konjac glucomannan chelate system, which enhances the three-dimensional network structure of the molecule; The shielding effect of metal cations will weaken the electrostatic repulsion between -O- in konjac glucomannan and compete with each other, thus affecting the rheological properties. The modified konjac gum not only improves the rheological property of its aqueous solution but also improves its water solubility. The operation process is simple and green.
The Design of a Mechanical Temperature-driven Shut-off Valve
Authors: Zheng-Cun Zhou , Chun-Bai Cui , Xiao-Bin Zhu
Published: February 2023

The structural design of a mechanical temperature-driven shut-off valve used in the water and steam sampling device of a power plant is designed using a Iventor drawing software. A NiTi shape memory alloy with high temperature-sensitivity is used as the driven spring to control the opening and closing of the valve. In addition to the design of the structures and common parts of the shut-off valve, the mechanical calculation and parameter-design of the driven spring are also carried out. The valve is unimpeded and can take water-steam samples under the normal state. When the temperature exceeds a 49 oC, the valve will be shut off due to the driven spring extends and the water intake will stop. When it is necessary to take water-steam samples again, it can be reset manually.