bluuebunny/crossref_metadata_2025 huggingface dataset:
Active optimization method of wind farm operation parameters remote test equipment based on Data Mining
Authors: Ma Rui , Xia Xuwei , Liu Jia , Huang Mingyu , Li Yongliang , Zhu Dongge
Published: February 2021

The function of remote test equipment for wind farm operation parameters is complex, which requires timely and accurate equipment tuning in complex environment. In order to achieve the above requirements, an active optimization method of wind farm operation parameters remote test equipment based on data mining is proposed. Combined with the data mining technology, the remote test characteristic data of wind farm operation parameters are collected. In order to grasp the operation status of the equipment timely and accurately, the remote test equipment is used for dynamic adjustment, and the real-time data update model of remote test is established and installed. Finally, the experimental results show that the active tuning method based on data mining for wind farm operation parameters remote test equipment is significantly higher in the actual application process, and fully meets the research requirements.
Analysis on Current Situation of Yunnan’s Demand Response and Research on Improvement Methods
Authors: Ma Gaoquan , Wang Bangcan , Xie Mengfei , He Peishan , Huang Yifan , Gao Ciwei
Published: February 2021

At present, the implementation of DSM fails to effectively alleviate the seasonal and periodic power shortage in Yunnan Province, and it is still dominated by the active regulation of power grid companies, lacking of market-oriented mechanism. Based on the experience of Jiangsu and Shandong Province in demand response, this paper puts forward several problems in Yunnan Province, such as the lack of basis for formulating demand response subsidy price, the platform construction has not yet realized the power data access of main power users, the implementation of demand response is imperfect and lacks market-oriented mechanism. On this basis, improvement methods are proposed, including distinguishing the capital sources of peak shaving and valley filling demand response, promoting the construction, development and operation and maintenance of the demand response platform of Yunnan energy investment group, and actively organizing enterprises to apply for DSM demonstration enterprises and products in the industrial field.
Accelerated Aging Experiment of IGBT under Pulsed Power and Reliability Studies
Authors: Mao Yinhao , Sun Zhaolong , Yuan Zhifang , Pan Xiaochen
Published: February 2021

Pulsed power technology gives full play to the characteristics of high pulses in the form of short pulses, and gradually occupies a certain position in industrial applications. It needs to ensure stability and durability while ensuring that the working parameters are met, the switching performance is particularly important., therefore, the reliability study of IGBT power module becomes an inevitable requirement for reliability evaluation in engineering. This article mainly introduces the experimental method of the accelerated aging experiment of IGBT under pulsed power conditions. The electro-thermal simulation is carried out through PLECS and the low-power experimental platform is built to obtain experimental data. Finally, the experimental data is analyzed, and the change rule of the failure characteristic parameters with the aging process under the pulse power condition and the IGBT failure standard different from the typical operating condition are obtained.
Research on Self-Configuration Technology of Intelligent Recorder Based on Graph and Model Integration
Authors: Chen Xu , Zhang Chi , Huang He , Xu Peng , Yang Jingchao , Xu Zhongnan
Published: February 2021

Intelligent recorder configuration related to smart operation and maintenance of secondary equipment has a large workload and a long configuration cycle, and it is difficult to guarantee and verify the correctness. Based on analysis of intelligent recorder function model including smart operation and maintenance, fault recording, network message analysis. This paper defines the requirements of self-configuration of intelligent recorder. On this basis, it puts forward the information model foundation that self-configuration depends on, including primary equipment model, correlation model between primary and secondary equipment, relays’ ICD information model, intelligent recorder acquisition unit, management unit model, and finally gives the self-configuration technique scheme in order to effectively improve the configuration efficiency of the intelligent recorder based on graph and model integration configuration, by which the RCI model file of the intelligent recorder and the SVG graphic file of the protection panel are formed.
Emergency control strategy of power system transient instability based on DBN
Authors: Qiang Ziyue , Wu Junyong , Li Baoqin , Zhang Ruoyu , Qin Liuyun
Published: February 2021

In order to satisfy the real-time emergency control decision-making after power system transient instability, an emergency control strategy based on deep belief network is proposed in this paper. Firstly, the DBN instability degree prediction model is established to fit the mapping relationship between generator power angle characteristics and transient stability coefficient; secondly, according to the fitting instability degree index, the sensitivity of generator tripping is solved to determine the generator tripping control action bus; finally, according to the emergency control optimization model and transient stability constraints, the optimal generator tripping strategy is solved and verified in New England 10-machine and 39-node system. The results show that the proposed method has high prediction accuracy and
efficiency, which can make the unstable system quickly resume stable operation.
Research and implementation of condition monitoring and evaluation for process switch of intelligent substation
Authors: Liu Haitao , Zhang Shuang , Xue Fei , Niu Jian , Xu Zhongnan , Han Yehong
Published: February 2021

There are some problems in the regular inspection of switch, such as lack of real-time, lack of maintenance and over maintenance, this paper proposes a method for monitoring and evaluating the status of process layer intelligent switches . According to IEC61850 standard, the information model of switch is established to obtain the status information of the switch. The status information data is analyzed through the monitoring model of over-limit, synchronization, mutation and trend warning, and the status of switch is quantitatively evaluated by the fuzzy comprehensive evaluation algorithm. The example shows that this method can effectively evaluate the state of switch, which provides application technical support for state maintenance of process layer intelligent switches.
Data-driven management mechanism of demand response resources in active distribution networks
Authors: Yin Jianbing , Xu Zeyu , Chen Lin , Li Dairui
Published: February 2021

As power distribution networks have been transferring from passive to active, conventional physical-driven models are incompetent to deal with the challenges of flexible and fast-changing operating conditions. Alternatively, data-driven methods, especially deep learning methods, have unique advantages in tackling those challenges. To this end, the paper first introduces the opportunities brought by the massive amount of data in active distribution networks (ADNs). Then the paper employs neural networks to identify load categories and their potential capacity of demand response to interact with ADNs. Furthermore, a generalized dispatch framework is presented to coordinate flexible loads for peak-valley electricity alleviation, with long-short-term-memory networks as an example. Last, the paper sheds light on the limitations of deep learning applications such as data cleaning and cybersecurity attacks.
Integrated pricing mechanism for combined electric and heat systems considering heat time delays.
Authors: Xie Pingping , Mao Tian , Xuan Peizheng , Zou Jin , Lu Siyu
Published: February 2021

Combined electric and heat systems can significantly improve fuel efficiency and reduce carbon emission by making use of complementary properties of electricity and heat. However, many current papers on the energy market mechanism do not consider the heating price, while some do not address the challenges of heat time delays on prices, which may impede the benefits of system operators as well as users. Therefore, in this paper, we extend the electric local marginal price (LMP) to the integrated LMP (ILMP) for electricity and heat in combined electric and heat systems considering heat time delays and network constraints. The results of case studies demonstrate the proposed mechanism can provide fair electricity and heat prices which can reflect generation cost, power loss, network congestion, and time delays.
FPGA-based Adaptive Variable Step MPPT Real Time Simulation for Photovoltaic Systems
Authors: He Ruxun , Wang Shouxiang , Zhang Chunyu , Ma Qi
Published: February 2021

In order to obtain more output power, maximum power point tracking (MPPT) control technology is usually designed to track the maximum power of photovoltaic (PV) array. The traditional power disturbance observation method tends to cause power oscillation loss, so an adaptive variable step algorithm is presented to balance the tracking accuracy and speed of PV system. Different from off-line simulation, the overall model is built on FPGA to complete the real time digital realization of MPPT control for PV system. Finally, the model is simulated and verified by ModelSim software. The experimental results show that the system can track the maximum power more quickly and accurately in real time.
Research on the Structure and Control Strategy of Energy Storage Grid Connected Inverter
Authors: Wang Cunping , Yu XiJuan , Li Hongtao
Published: February 2021

This paper studied the structure of energy storage grid connected inverter which is composed of super capacitor, bi-directional DC/DC converter, and voltage type DC/AC converter. The working principle of bi-directional DC/DC converter and DC/AC converter was separately analyzed. Then a joint control strategy of DC/DC converter and DC/AC converter was proposed with the main control objective of maintaining DC bus voltage. According to the different states of DC bus voltage and super capacitor voltage, five control modes of energy storage inverter were set. Besides, the DC/AC converter was controlled to compensate the reactive power and harmonics, and provide certain active power for the power grid according to the actual situation. Finally, the effectiveness of the proposed energy storage inverter structure and control strategy were verified through simulation analysis.
An Real-Time Emergency Control Method Based On Unbalanced Transient Energy Function
Authors: Huang Dan , Zhao Shanshan , Zhang Yichi , He Hailei
Published: February 2021

In this paper, an emergency control strategy by combining generator tripping and load shedding is presented. Firstly, the unbalanced transient energy function of power system is defined, and its key features are analysed. Then, by combining the unbalanced power characteristics for power system in steady state operation condition, the method for calculating the control quantities of generator tripping and load shedding is proposed. Furthermore, a realtime closed-loop emergency control strategy is proposed. Since the proposed method by only using measurement data is based on the essential of transient instability, the accurate control quantities can be obtained. Compared with single generator tripping control, the low frequency and low voltage problem of system can be improved effectively with the combined emergency control strategy. Simulation results of New England 39-bus system validate the effectiveness of the proposed control strategy.
Analysis and countermeasures of delayed action of generator stator grounding protection
Authors: Liu Shifu , Qian Zhunli
Published: February 2021

The friction between the iron core and the wire rod caused insulation damage, which caused the wire rod to discharge to the ground, the generator stator ground protection action, and the generator stopped, through the analysis of the reasons, the generator operation preventive measures were formulated, and the delay time of the stator grounding protection was shortened and neutrality was adjusted. The improvement measures for shortening the delay time of stator grounding protection, adjusting the neutral point TV transformation ratio, increasing the impedance of the secondary load, and unified protection clock are proposed. These improvement measures provide useful experience for engineering and technical personnel to deal with related similar problems.
Research on optimal allocation of protective resources of power network under malicious attacks
Authors: Xiong Jingyi , Hou Benwei , Du Xiuli
Published: February 2021

With the increase of global malicious activities, it is particularly necessary to optimize the allocation of limited urban protective resources and protect power network from malicious attacks. There is plenty of research on evaluating the risks of malicious attacks on electricity network, however, conventional risk-based approach does not take strategic adjustment of malicious into account, nor can it determine the optimal allocation of global protective resources. In this paper, an optimal allocation of protective resources based on game theory was proposed, which combined game theory with risk assessment, taking full account of strategic interaction between defender and attacker. IEEE 30-bus network was taken as an example to verify the applicability and reliability of the method, so as to confirm the advantages of the method in determining the global optimal allocation of protective resources.
Energy Internet Security Risk Evaluation Index System
Authors: Li Jing , Shang Zhijie , Qiang Ren , Pang Jin , Guo Han , Wang Jingchu , Niu Haihang
Published: February 2021

As the construction of the Energy Internet has launched into a novel method, the dependence on energy and information networks has been greatly increased. The interaction of energy and information flow has become recurring, and the deep coupling of energy and information flow has been realized. As a result, security risk factors have increased substantially. Given that, this article from the perspective of energy and information flow, combined with the “Source-Grid-Load-Storage” coordination scenario of the energy Internet and the actual development needs of the information network, this article proposes a risk assessment for many security risks that threatens the stable construction of the energy Internet Index system and corresponding index analysis.
A Short-Term Optimal Dispatch Model Considering Uncertain Wind Power Output
Authors: Zhang Xuan , Wei Hua , Gao Wei , Su Xianxin
Published: February 2021

Aiming at the security and economic problems caused by wind power connected to the grid, a short-term optimal dispatch model for power system considering the uncertain wind power output is proposed. Although wind power is an important clean energy source, wind power output is characterized by volatility and randomness, which damages the system power balance and brings difficulties to dispatching. In this paper, wind power output characteristics are described by uncertain sets of wind power output. Considering the positive and negative spinning reserve constraints, a bi-level optimization model is constructed. According to the dual principle, the bi-level optimization model can be transformed into a solvable robust optimization scheduling model. Finally, the numerical simulation shows that the proposed method can realize the utilization of wind power, rationally arrange the commitment operation and output of thermal power units, which has good robustness to wind power output fluctuations to ensure the safe and economic operation of the system.
Face recognition technology based on CNN, XGBoost, model fusion and its application for safety management in power system
Authors: Xu Xianghai , Wang Xuan , Sun Zhiqing , Wang Shouxiang
Published: February 2021

The safety maintenance of operating site is important for safety management in power system. With the development of artificial intelligence (AI) and popularization of monitoring camera, face recognition technology is widely utilized in operating site of power system. To improve the capability for safety management of operating site in power system, a face recognition model based on convolutional neural network (CNN), eXtreme gradient boosting (XGBoost) and model fusion is built. Firstly, pre-processed images are input into CNN to obtain the recognition probabilities of various face and the extracted face features. Secondly, the extracted features of CNN are input into XGBoost to obtain the recognition probabilities of various face recognized by XGBoost. Finally, above two groups of probabilities are weighted by model fusion technology to obtain the final recognition probabilities of various face, and the final face recognition results are output. Simulation results show that CNN has better capability of feature extraction, and the proposed face recognition model has the highest recognition accuracy among those advanced face recognition models. In addition, this paper describes the application based on the proposed face recognition model in non-working personnel recognition, trajectory tracking of operators, etc, so as to greatly improve the safety management of operating site in power system, which not only ensures safety, but also reduces unnecessary management expenses.
Analysis on propagation characteristics of voltage sag through different types of transformers
Authors: Jiang Jiandong , Gao Ang
Published: February 2021

Transformer is a key factor that can not be ignored in the process of voltage sag propagation. In this paper, the transmission characteristics of voltage sag caused by different types of short circuit are analyzed through the different transfer matrix of transformer with different connection methods, including amplitude change, waveform distortion and phase jump. The distribution network model is established by PSCAD, and the propagation characteristics are verified. The conclusion has certain significance for judging the type of voltage sag from the load side, evaluating the degree of voltage sag, and selecting the treatment measures of voltage sag.
Fault identification based on BP neural network and wavelet packet in power systems
Authors: Tao Fang , Qian Sun , Hangli Jian , Ning Li , Yan Zhou , Yanjie She , Zhangao Li , Ying Cai , Leiyu Zhao , Jiang Li
Published: February 2021

This paper proposes a fault identification method based on BP neural network and wavelet packet, which extracts the fault transient eigenvalues of the three-phase current and zero-sequence current from measurement data under the fault conditions. Firstly, the eigenvalues of three-phasors are sampled under the typical faults, such as single-phase ground fault, two-phase short-circuit fault, two-phase ground short-circuits fault, and three-phase short-circuit fault. Secondly, the three-phase current and the zero-sequence current are subjected to wavelet packet transform to extract the eigenvalues, which are viewed as the input of the neural network to determine the fault type. Finally, simulation results show that the proposed method can give reliable identification results under different fault conditions.
Fractional Order PID PLL Controller Based on Particle Swarm Optimization Algorithm
Authors: Tang Yun , Xiong Hejin , Ye Qian
Published: February 2021

In this paper, a Fractional Order PID PLL controller based on particle swarm optimization algorithm is proposed for power grid system. The parameters of Fractional Order PID controller are optimized by particle swarm optimization algorithm, so as to control the orthogonal signal generator in PLL, realize accurate phase discrimination and effectively suppress grid harmonics.In this paper, firstly, the mathematical model of PLL is established, and then the PID controller and Fractional Order PID controller are compared and controlled. Finally, the parameters of Fractional Order PID controller are optimized by particle swarm optimization algorithm to achieve the optimal control.In this paper, the simulation of PLL controller is completed based on MATLAB / Simulink. The simulation results show that the Fractional Order PID based on PSO algorithm can automatically find the optimal control parameters, realize the precise control of PLL, and improve the ability of filtering harmonic and dynamic performance of power grid.
Detection method of voltage sag disturbance based on improved HHT
Authors: Fang Yisheng , Pang Hongyuan , Chen Yong
Published: February 2021

In order to improve the detection accuracy of Hilbert Huang transform (HHT) for voltage sag signal, an improved HHT method is proposed: the boundary local feature scale method is combined with CEEMDAN, the former is used to suppress the end effect in the EMD process, and the latter is used to improve the mode aliasing between IMF components. The simulation results show that the improved method can extract the instantaneo us characteristics of the disturbance signal more accurately and quickly, and realize the accurat e positioning of the start and end moments of the sag. Finally, the measured data is used to compare the traditional HHT and the improved HHT method. The results show that the improved HHT method improves the detection accuracy of the sag signal, and has certain reference value for the study of voltage sag feature extraction.
The effect of PSS on the synchronous condenser to reduce a wind farm included system oscillation
Authors: Maoqing Wang , Wenfeng Li , Shijun Ma , Zongxi Zhang
Published: February 2021

Distributed condenser will be used on wind farm in the future to supply reactive power support to the power system. How would the power system stabilizer (PSS) on the condenser effect the stability of the power system? How to configure PSS parameters to make PSS have better effec? These questions are researched in this paper.
A Recognition Method for Time-domain Waveform Images of Electric Traction Network Overvoltage Based on Deep Learning
Authors: Junyi JIA , Mingli WU , Qi WANG
Published: February 2021

A large amount of time-domain waveform images of overvoltage of electric traction network are collected during the on-board test of EMU. The traditional time-domain or frequency-domain analysis and classification method can’t be directly applied to time-domain waveform images. In order to analyze these images, firstly, image preprocessing is carried out. Then, the data set of time-domain waveform images is established. Finally, the CNN (convolutional neural network) classification model is trained based on data set. The results show that the sensitivity of recognition is above 81%, and this method is suitable for the time-domain waveform image of overvoltage of electric traction network.
Study on generation expansion planning evaluation method based on envelope optimization model
Authors: Maowen ZHOU , Jin CHEN , Zhengsheng WU , hangyu Wan
Published: February 2021

Participants involved in power generation construction were incomplete information and decision-making with bounded rational. Their motivations and behaviours may deviate from environment-friendly and social-welfare generation expansion planning. This paper proposes an envelope optimization model, which aims to meet the goals of minimizing the amount of abandoned water and maximizing the proportion of non-fossil power generation. And it presents a method for evaluating a certain generation expansion planning scheme quantitatively by using this model to calculate non-fossil power sources proportion and abandoned water electricity indicators. Finally, this evaluation method is proved by a regional power system’s generation expansion planning scheme example. The generation expansion planning evaluation method presented in this paper is flexible and practical, which is conducive to guiding and evaluating short-term and long-term regional power development schemes.
Research on battery pack fault pre diagnosis method
Authors: Dong Dong , Tian Yu , Liu Shuangyu , Qian Dongpei , Wang Jonggeng , Lin Decai , Xu Junjie , Yan Guanglong , Lin Xile , Liu Zhongcai
Published: February 2021

At present, most of the BMS in the market set a constant fault threshold, but with the increase of the number of power battery recycling, the external characteristics of the battery will also change. A constant fault diagnosis threshold may also occur after battery aging diagnosis is not timely. Battery cell voltage is the direct embodiment of the external characteristics of battery cell, so the fault diagnosis of battery cell voltage is the most important. Too high or too low cell voltage is the most obvious fault. Normally, this should not happen. Of course, due to the gradual aging of the battery pack, the inconsistency between the monomers and the charged state of each cell, the inconsistency of the voltage of each cell can not be avoided. However, the voltage difference caused by cell manufacture or inconsistency is limited in the case of aging degree.Based on the battery discharge data, the purpose of this study is to propose a method to identify the gradual fault signal in advance and reduce the problems caused by the sudden failure of the battery by detecting and diagnosing the change trend of the extreme value difference of the historical operation data.
Prediction Methods for Energy Internet Security Situation Based on Hybrid Neural Network
Authors: Liu Dongmei , Cheng Jie , Yuan Zilong , Wang Chan , Huang Xingjie , Yin Hongshan , Lin Nan , Niu Haihang
Published: February 2021

Under the duplex framework of the rapid transformation of the conventional power grid to the energy Internet and the swift development of network attack technologies, the security and protection of the energy Internet are becoming increasingly precarious. The energy Internet attack prediction method has become a current research hotspot. The current research in this area is predominantly focused on security to protect and reduce losses, it is impossible to counter the attacks faced by the Energy Internet promptly, and there is a lack of online predictive security analysis methods and tools. Aiming at the shortcomings of traditional research and the current stage, this paper proposes an online prediction and analysis method of energy Internet security situation based on the combination of temporal convolutional neural network (TCN) and gated recurrent neural network (LSTM). This method which based on the security status data set can predict and analyse the region Energy Internet security, and the mean absolute error and mean squared error are 0.352 and 0.2714 respectively. The results show that the prediction performance of the algorithm has been improved, the stability is robust, and it can be applied to the energy Internet security situation prediction.
Output control of wireless power transmission system based on dynamic parameter tuning
Authors: Xu Benchao , Wang Zhihui , Shi Ke , Long Hao , Tang Chunsen
Published: February 2021

Flexible output power control is very important for wireless power transmission system. In the wireless charging application of electric vehicles, the load is usually the battery. For the battery, both constant current charging and constant voltage charging are needed. In the constant voltage stage, the current should continue to decrease, so we need to adjust the output current of the system in the later stage of charging. Nowadays, the main methods used in WPT system are phase shift and pulse width modulation, adding a first stage DC-DC circuit before the inverter, and controlling the energy injection of the transmitting coil. In view of its shortcomings, this paper uses a method based on adjusting capacitor parameters to achieve output control. Firstly, the influence of capacitance parameters on output current is analyzed, and the relationship between capacitance parameters and output current is deduced; secondly, its advantages are analyzed, and the working principle is analyzed through simulation; finally, the feasibility and correctness of the control method are verified by experiment and simulation.
Design of Wind Farm Information System Based on Blockchain Technology
Authors: Wang Haitao , Wu Bin
Published: February 2021

The current wind power operation and maintenance management has difficulties in data storage, insufficient security, and weak sharing. Therefore, this paper proposes to use the blockchain to build a wind farm information system to solve these problems. This paper analyzes the applicability of blockchain and wind farm information system, and designs the functional modules of the wind farm information system and the corresponding system framework.
Application of Error Function in Dead-end/cross-flow Microfiltration Mode
Authors: Hu Ge , Zhong Chenyin , Wang Zhan , Wang Xi
Published: February 2021

In this study, error function was used to analyze the membrane fouling behavior (flux decay) for bovine serum album (BSA) solution in dead-end mode and for kaolin suspension in cross-flow mode under constant pressure. The results showed that the predictions of error function had good agreements with experimental data both in dead-end mode and cross-flow mode. Meanwhile, both higher concentration and higher TMP could accelerate the membrane fouling rate. In addition, the parameter k in error function decreased with the increase of concentration or TMP. Thus, smaller parameter k represented more serious membrane fouling.
Prediction method of coal mine goaf temperature and its practical application
Authors: Xinhai Zhang , Hui Zhu
Published: February 2021

Spontaneous combustion of coal seams in goaf seriously threatens the development of the coal mining industry. The prediction of goaf temperature is of great significance for mine disaster prevention. Based on the energy conservation equation of floating coal in goaf, the analytical solution of the steady-state temperature field in goaf is derived in this paper, and the temperature of goaf can be calculated simply through a series of physical and chemical parameters. This method is applied to Kaida Coal Mine to calculate the temperature of goaf at the return air side of 46205 working face. The results show that although there is some error between the calculated value and the measured value of the temperature in goaf, the predicted results can reflect the change rule of the temperature in goaf, and provide some guidance for the prevention and control of coal spontaneous combustion in goaf. With the increase of buried depth, the floating coal temperature rises first and then decreases. It is estimated that the maximum temperature of goaf is 27.11 °C, which is located 25m deep in goaf.
A Two-Layer Optimization Model for Energy Storage Configuration in the Distribution Network
Authors: Ma Tianxing , Gu Hui , Zha Zhijun , Li Guoshun , Luo Honghao
Published: February 2021

The large-scale access of electric vehicles will aggravate the peak-to-valley load difference of the distribution network, and the intermittent power generation of high-penetration renewable energy also threatens the safe operation of the distribution network. Energy storage is widely used in the fields of power peak load shifting and access of renewable energy. This paper proposes a two-level optimization model that considers both planning and operation of energy storage system. At the planning level, a method for the location and capacity of energy storage is proposed based on the economics of the distribution network. At the operation level, a scheduling strategy applying to different seasonal scenarios is proposed to achieve the best effect of peak load shifting. The simulated annealing particle swarm algorithm with good convergence performance is used to solve the model. Finally, the performance and economic benefits of the model are demonstrated through simulation research.
Research on the Impact of Xiamen VSC-HVDC on the Short-circuit Current Level of the Power Grid and the Suppression Measures
Authors: Su Qingmei , Huang Ting , Li Kewen , Zhang Huiyu , Huang Daoshan , Lu Yingquan
Published: February 2021

After Xiamen VSC-HVDC Project is put into operation, it can improve the power supply capacity and reliability of Xiamen Power Grid.But at the same time,it also brings new problems to the operation of the power grid, among which the short-circuit current problem is particularly prominent.In the preliminary analysis of power grid operation, using the short- circuit current program (PSD-SCCP) commonly used in domestic power grid simulation analysis to calculate to be found that:VSC-HVDC will provide a large short-circuit current when the AC grid is short-circuited, causing the short-circuit current levels of multiple 220kV busbars of the Xiamen Power Grid to approach or exceed 50kA, which brings greater pressure on the adjustment and arrangement of the grid operation mode.Therefore, it is necessary to study the true level of the impact of Xiamen VSC-HVDC on the short-circuit current of the AC grid based on the actual control logic of the Xiamen VSC-HVDC project, in order to propose more accurate short-circuit current suppression measures to achieve bipolar operation of Xiamen VSC-HVDC.
The Application of Digital Twin on Power Industry
Authors: Huang Jianping , Zhao Linlin , Wei Fuwang , Cao Bingwen
Published: February 2021

Digital Twin (DT), integrating some current popular technologies, such as smart sensors, 5G communications, cloud platforms and big data analysis, is an integrated multidiscipline, multi-physical, multi-scale and multi-probability simulation process. To promote the accelerated development of China's manufacturing industry, it is needed to develop a smarter new generation of Smart Power System (SPS), and it is time for DT’s emergence. This system can comprehensively improve the intelligence of grid operation by using DT, which is driven by the data stream generated by the smart grid. Besides, it uses real-time situational awareness and uses real-time virtual deduction as cognitive means, and real-time feedback from virtual space to real space as an iterative method. Based on the applications of DT in the power industry, this article analyzes some applications in power system control, equipment fault prediction and diagnosis, and power online analysis from the demand for the core technologies of DT and DT of power system intelligence. Thus, the design framework, core technologies and implementation approaches of the Power System Digital Twin (PSDT) are presented. Finally, the challenges faced by the applications of DT in the power industry are analyzed, and the future trend of the power of DT is summarized.
A failure analysis of a generator unit shutdown due to short circuit of generator positive and negative collector rings
Authors: Liu Shifu , Qian Zhunli
Published: February 2021

Taking the short circuit faults of the positive and negative collector rings of a 40MW gas turbine generator as an example, the failure process of the generator's positive and negative collector rings is analyzed, the process of failure occurrence is explained, and the cause of the failure is analysed, the main reason for the failure is that the air inlet filter of the collector ring chamber of the generator is damaged and falls off, and the broken and dropped filter screen enters the collector ring chamber with the wind, which causes a short circuit of the positive and negative collector ring. Finally, the corresponding treatment and preventive measures are formulated.
Research on key issues of power spot market construction
Authors: Guo Hongzhen , Li Tengjian , Xu Ming , Song Wenqin , Tuo Jianjun
Published: February 2021

Power spot market is the key link of the power market system. It plays a fundamental role in supporting the opening, competition and orderly operation of the power market. It is also the key to coordinate market transactions and system security.Based on the comprehensive comparison and analysis of the construction practice of power markets in different countries, this paper analyzes and studies the key issues in the organization and operation of the power spot market, such as market operation organizers and their responsibilities, market price and clearing mechanism, and puts forward some innovative suggestions for the construction of power spot market.
The effectiveness evaluation of system construction for compliance management in the electricity market
Authors: Jin Luosong , He Chang , Wang Xiangyang , Wang Miao , Zhang Lu
Published: February 2021

The establishment of a scientific and effective evaluation index system is essential for the healthy development of China’s electricity market. This paper focuses on the effectiveness evaluation of the system construction for compliance management. We propose a three-level index system of compliance management. Further, the weight of each index is measured by the weighting method for group decision based on AHP method. Finally, a modal analysis has been made to illustrate the suitability and effectiveness of the proposed framework. Some suggestions on compliance management are provided to ensure the sustainable development and promote the electricity market reform in China.
STUDY ON BOUNDARY CONDITIONS OF GROUND ANCHORED CABLE STAYED BRIDGE WITH SINGLE INCLINED TOWER
Authors: Zhang Yajun , Wang Xiaoshan , Liu Yahao , Li Ranran
Published: February 2021

In order to study the influence of boundary conditions at the bottom of the tower on the structural characteristics of a ground anchored cable-stayed bridge with single inclined tower, taking a bridge project as an example, the finite element model is established to study the static, dynamic and overall stability of three structural systems, namely, universal hinge connection, unidirectional hinge connection and consolidation connection, between the bridge tower and the concrete tower base. The results show that: The internal force can be reduced by universal hinge connection between tower bridge and tower base, and structural deformation can be reduced by choosing consolidation method. However, there will be huge torque and transverse bending moment at the bottom of tower, so the consolidation system should not be selected first; the dynamic characteristics of the three systems are different, but the dynamic characteristics of the main girder are basically the same. In terms of stability, the boundary conditions have little effect on the low-order instability modes of the structure, and the stability can be considered as the final factor of the structure selection.
Comprehensive optimization of distributed generation considering network reconstruction based on Archimedes optimization algorithm
Authors: Li Yingliang , Zhu Hao , Wang Deming , Wang Kang , Kong Weixu , Wu Xiaomeng
Published: February 2021

To mitigate the effect of the distributed generation (DG) connection on the voltage profile and power loss, the DG optimal configuration and network reconfiguration are used in distribution automation. In this paper, a new optimization method named Archimedes Optimization Algorithm (AOA) is proposed, unifying the DG optimal configuration and network reconfiguration. The DG locations and capacities are coded by integral and real numbers simultaneously in the proposed method. The integer mesh-network coding method is integrated into the new method to solve the network reconfiguration problem. The new method is compared with the Improved Genetic Algorithm (IGA) as well as the Particle Swarm Optimization (PSO). Results demonstrate that the proposed method has advantages in improving the voltage profile and reducing the power loss.
Research on Regional Difference of Energy Consumption in Production Stage of Civil Building Materials based on Theil Index
Authors: Yuefei Liu , Jing Liu
Published: February 2021

Total quantity control is an important means to achieve the goal of building energy conservation in China, but the statistical method of energy consumption data in the production stage of civil building materials has not been established yet. This paper firstly constructs the calculation method of energy consumption in the production stage of civil building materials according to the usage amount of building materials, and then obtains the data of energy consumption in the production stage of civil building materials from 2008 to 2017 according to the statistical yearbook. Then, 30 provinces and cities in China are divided into 3 regions. According to Theil index analysis method, the regional differences of the production energy of China's civil building materials from 2008 to 2017 are calculated. According to the calculation results, China's energy consumption in the production stage of civil building materials shows an overall trend of convergence growth, but the intra-regional difference is greater than the inter-regional difference. The Theil index is the highest in the western region, but the contribution rate of the Theil index is the largest in the eastern region.
Three-dimensional simulation analysis of electric field distribution at the middle joint of 110 kV cable with typical defects
Authors: Xu Siqin , Huang Xiangqian , Yang Song , Yu Bin , Gan Pengfei
Published: February 2021

The joint of high-voltage cable is the weakest part in the whole cable system, and the local defect of the middle joint will affect the distribution of the internal electric field. This paper establishes a three-dimensional model by finite element simulation software based on the electric field calculation equation in Maxwell equation system. The influence of typical defects such as impurity, scratch and air bubble on the electric field distribution in the middle joint is analysed. The results show that the internal defects of the middle joint may cause distortion of the local electric field strength in the middle joint, which may lead to deterioration of the insulation.
Analysis of the influence of control parameters on the interaction between direct-driven wind turbines
Authors: Xin Guifeng , Cao Na
Published: February 2021

In order to study the influence of control parameters on the interaction between direct-driven wind turbines, this paper presents the interaction model and analysis method of direct-driven wind turbines. Firstly, the harmonic linearization method is used to establish the interaction model of two direct-driven wind turbines, and the interaction mechanism between the two units is studied; secondly, the influence of phase-locked loop and DC voltage loop on the interaction between the two units is analyzed from the perspective of bandwidth and damping ratio of second-order closed-loop transfer function, and the interaction law of phase-locked loop and DC voltage loop on the interaction between the two units is studied and summarized; finally, the time-domain simulation of the two units grid-connected system is carried out, and the results are compared with the frequency domain analysis results to verify the rationality of the theoretical analysis.
Hydrodynamic and Structural Stability Analysis for Shaft Tubular Pump Unit
Authors: Yang Jianfeng , Fang Guocai , Hu Daming , Cai Zhizhou , Zhai Jianwei , Zheng Yuan , Kan Kan
Published: February 2021

Hydrodynamic and structural stability directly affect the efficiency and safety of pump units operation. In this paper, we simulated inner flow field of a shaft tubular pump unit through Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) for exploring the blade pressure and dynamic stress characteristics, where first part focus on the hydrodynamic pressure fluctuation on inlet and outlet of impeller and second part focus on dynamic stress distribution in time and frequency domain on pump impeller. Monitoring points are set at the inlet and outlet of impeller to obtain the dynamic pressure, then mapping the time domain data to frequency domain through Fast Fourier Transform (FFT) method. The results show that the pressure fluctuation has strong periodicity, and the fundamental frequency of the pressure fluctuation on the inlet and outlet surfaces is the blade passing frequency and the blade passing frequency respectively, which means the rotation of impeller and rotor stator interaction (RSI) phenomenon between impeller blades and guide vanes are the origin of hydrodynamic pressure fluctuation. Hydrodynamic pressure on impeller blade is applied to the impeller structure to obtain structural responses, results show that maximum dynamic stress appears in the root of impeller blade, the dynamic stress fluctuate in the nearby of static stress concentration and maximum dynamic stress appear in the permissible stress range. In frequency domain, the basic frequency and secondary basic frequency are impeller blade passing frequency and guide vane passing frequency, which indicated that the major reason of impeller dynamic stress fluctuation is water excitation pressure.
Application of Artificial Intelligence in Industrial Automation Control System
Authors: Li Qiyao
Published: February 2021

Automatic control system is an important part of industrial production and manufacturing. With the rapid development of computer technology, a new generation of intelligent technology represented by artificial intelligence has been applied to industrial automation system. This paper introduces the development of the current industrial automation control system in detail, and then describes the relevant theory of artificial intelligence technology. Finally, it describes the application of artificial intelligence technology in industrial automatic control system and its future development trend. This paper aims to provide a reference for the research of industrial automation control system.
Research on optimal Dispatching Strategy of micro-grid based on Particle Swarm optimization algorithm
Authors: Wang Ning , Li Hongtao , Zhang Qianmao , Shi Litao , Geng Xin
Published: February 2021

Optimizing micro-grid dispatch is one of the important ways to improve the efficiency of renewable energy utilization. In this paper, a micro-grid system, including photoelectric, wind power, diesel engine, and the battery is optimized based on the Particle Swarm Optimization algorithm. Constrained by operation condition, a multi-objective optimization scheduling model including fuel cost, operation cost, and pollution gas emission cost is established, and multi-objective Particle Swarm Optimization (MOPSO) is used to solve the optimization scheduling problem of micro-grid. The simulation results show that the model can promote the optimization of micro-grid dispatch.
Research on Fault Location Method of Distribution Network
Authors: He Xiangzhen
Published: February 2021

Distribution network is an important part of the power system, is the core link of power distribution, and is also the key node in the process of power grid operation. Once the distribution network fails, it is very important to determine the fault location quickly and accurately for the restoration of normal power supply. Aiming at the problem of distribution network fault location, this paper introduces the research status of distribution network fault location method in detail, introduces the existing distribution network fault location method in detail, expounds its application situation, analyzes the advantages and disadvantages of various methods in detail, so as to provide reference for the future research of distribution network fault location method.