bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on optimizing controller parameters based on transient energy function to improve the stability of weak transmission system
Authors: Xie Huan , Lu Jiali , Zhao Feng , Zhao Tianqi , Xu Peng , Xia Xue 
Published: March 2021

Abstract
This paper takes the Ximeng-Taizhou UHVDC transmission weak transmission end AC system as the background, and proposes to optimize the low-voltage current limiting control link (VDCOL )to improve the stability of the system. First of all, this paper analyzes the working principle and limitations of traditional VDCOL, and proposes that the short-circuit ratio of the sending end and the voltage of the commutation bus at the receiving end are used as the variables of the VDCOL cut-off voltage to achieve the effect of optimizing VDCOL. Make the cut-off voltage a value that changes with the change of the inverter side commutation bus voltage, which can take into account the recovery speed of the AC and DC systems. The process of constructing the transient energy function considering the dynamic characteristics of the DC system is analyzed in detail, and the real-time digital simulation software RTDS is used to build a single-machine infinite-DC simulation example. Based on time-domain simulation software and transient energy function margin method, the optimization of the low-voltage current-limiting control link in the DC control system is verified to improve the stability of the sending-end AC system.
An optimization and evaluation method construction of zero-energy residential building renovation
Authors: Wu Weidong , Meng Qi , Lv Yajun , Li Xinyang , Hou Huanyu , Gao Ying , Cao Wen 
Published: March 2021

Abstract
Zero-energy renovation is carried out on the envelope structures and renewable energy systems of the reference buildings, and control function was constructed with the energy-saving quantities in the total life cycle of the renovated and pre-renovation buildings, which was optimized and solved using the NSGAII (Non-dominated Sorting Genetic Algorithm II) to obtain the optimal renovation scheme. The entropy weight evaluation is employed to evaluate the optimal scheme. The reference buildings are subjected to energy-saving renovation according to the optimal method, and the relationship between energy supply and energy consumption is analyzed for each reference building in each month. This study offers a method for the optimization and evaluation of zero-energy consumption in residential buildings, which provides guidance for the zero-energy residential building renovation.
Research on AC/DC hybrid system real-time simulation progress improvement
Authors: Li Yang , He Guoqing , Zhang Xing 
Published: March 2021

Abstract
In order to improve the accuracy of real-time simulation of power electronic transformers, all models are based on FPGA modeling, and a mathematical model of power electronic transformers suitable for FPGA operations has been established. Aiming at the simulation error caused by multi-rate simulation, this paper analyzes the source of simulation error, proposes a step wave average communication algorithm, which improves the oscillation and jitter of simulation results. The simulation platform is connected to the real controller of power electronics and the real controller of new energy generation unit. The real-time simulation verification is carried out for the dynamic characteristics, control performance and stability of AC / DC system. The simulation results verify the reliability and practicability of the simulation platform.
Design and development of CEWES software for complex environment wind engineering simulation
Authors: Zhao Fan , Wu Shuang , Qi Chen , Bai Hanli , Wang Xianzhuo 
Published: March 2021

Abstract
The design and development of the complex environment wind engineering simulation software CEWES was carried out, relying on the National Numerical Wind Tunnel Project (NNW). First, based on the characteristics of the physical problem that the software aims to solve, the requirements for the development of complex environment wind engineering simulation software are proposed, and three main modules of the software will be developed: structured grid flow field solver, unstructured grid flow field solvers modeling module of complex terrain and surface. Subsequently, the appropriate mathematical and physical model and numerical solution algorithm are selected for the flow field solver. The CEWES software uses the finite volume method for discretization with second-order accuracy, solves the RANS equations based on the SIMPLE algorithm, uses the k-ε turbulence model to solve the turbulence, and supports large-scale parallelism calculation. Third, the software design was carried out in accordance with the requirements of the CFD solution process and the modular program, focusing on the program architecture, data structure and subroutine interface design, and coding implementation based on the detailed design. Finally, the CEWES software was tested with typical examples. The test results of the calculation examples show that the software calculation results have good accuracy and large-scale parallel computing capabilities, and are suitable for wind engineering simulations in complex terrain environments.
Scenario analysis of wind power output based on improved k-means algorithm
Authors: Wang Weiyuan , Dou Fei , Yu Xuan , Liu Gaowei 
Published: March 2021

Abstract
To ensure the safety and reliability of grid operation, an accurate description of wind power output is crucial. In this paper, the Grey Wolf Optimization algorithm (GWO) optimized by the Cuckoo Search algorithm (CS) is proposed to improve the traditional k-means clustering algorithm and the improved k-means algorithm is applied to the scenario analysis of wind power output. The simulation results show that the error between the typical scene and the initial scene is only 4.56% when reduced by the improved k-means algorithm, so the typical scene not only maintains the temporal sequence of the initial scene, but also fits the output fluctuation and randomness of the initial scene well.
A review of bearing fault diagnosis for wind turbines
Authors: Liu Bing , Liu Baixin , Dai Qingbin , Liu Huaping 
Published: March 2021

Abstract
Bearings are the core components of the wind turbine’s mechanical transmission system, but the bearings of wind turbines are prone to wear and failure during vibration, and it is often difficult to determine the fault-bearing status and fault location. Therefore, the monitoring and fault diagnosis of wind turbine bearing status are very necessary. This paper introduces the types of bearings of wind turbines and common faults of bearings, analyzes from the aspects of bearing vibration data and supervisory control and data acquisition (SCADA) systems, summarizes the existing fault diagnosis methods and systems of wind turbine bearings, and points out the basics of these methods thought. Finally, the research focus of future bearing fault diagnosis is elaborated.
NDM-based H-infinity robust control of parallel-connected grid-connected converters for V2G
Authors: Zhou Shilian , Li Longfang , Ben Shujun , Long Bo , Chen Yong 
Published: March 2021

Abstract
Because of the unignoring line-impedance, distorted grid voltage, high penetration and the increased parallel-connected grid-connected converters (GCC) in vehicle-to-grid (V2G) system, the stability of the grid with electric vehicle (EV) faces new challenges. To deal with the stability problem, this paper proposes a numerator-denominator-model (NDM) based H-infinity controller combined with an adaptive capacitive-current-feedback active damping method with explicitly robust stability in terms of variations on filter parameters, time-delay and grid-impedance. Simulation results are investigated in two parallel-connected GCC in EV and show the validity of the proposed method.
Research on control strategy of maximum power tracking variable step size perturbation & observation method for photovoltaic power generation system
Authors: Gao Zhen , Kai Fei , Xi Ziqiang 
Published: March 2021

Abstract
There are three defects of traditional perturbation and observation method in the maximum power tracking control process of photovoltaic power generation systems, which are oscillation, misjudgment and poor tracking accuracy. Thus, a variable step perturbation and observation method based on power prediction is proposed for three-level DC/DC converters in this paper, which effectively solved oscillation, misjudgment, tracking accuracy problems, improving the tracking speed and precision of the algorithm, and the verification results of the maximum power tracking algorithm based on the three-level DC/DC converter structure has also been indicated.
Optimization of back pressure control of direct air-cooling unit based on GPC
Authors: Bai Jianyun , Shao Ru , Ren Qi 
Published: March 2021

Abstract
In view of the fact that the actual back pressure is difficult to track the set value quickly and stably, this paper applies the predictive control algorithm (GPC) which can respond quickly, has good robustness and is easy to realize in the industrial production site to optimize the back pressure control. The control performance of the back pressure control system with PID, fuzzy PID and GPC is compared and analyzed through the simulation test. The simulation results show that the GPC algorithm has better dynamic performance than PID and fuzzy PID control in the case of set point disturbance and internal disturbance, and has stronger robustness in the face of model mismatch. To sum up, GPC algorithm is more suitable for the back pressure control system under complex working conditions, and the optimization control method has a certain guiding significance for the actual production site back pressure control strategy improvement.
Simulation analysis of the influence of compressor speed on a solar-assisted heat pump hot water system
Authors: Li Zuqiang , Huang Xinghua 
Published: March 2021

Abstract
Inverter compressors have great potential in improving the overall performance of the solar-assisted heat pump (SAHP) system. However, in the actual process, due to the uncontrollability of environmental factors, the relationship between compressor speed, environmental factors and system performance is complicated, so that it is difficult to obtain intuitive data through operating experiments. Therefore, based on the SAHP system, a quasi-steady-state mathematical model is established using the Engineering Equation Solver (EES). And use this model to study the relationship between compressor speed and heat pump system performance. The simulation results show that when the ambient temperature is 20°C, if the heat collection efficiency is not lower than 0.45, when the solar radiation intensity is 400, 600 and 800 W/m2, the best compressor speed values are 1600, 1800 and 2400 r / min, the corresponding system coefficient of performance (COP) will reach the maximum value at this time, which are 7.7, 8.6 and 8.4 respectively. In addition, compared with higher solar radiation, at lower solar radiation intensity, increasing the compressor speed can significantly increase the heating capacity of the system.
Transparent, stretchable and high-performance supercapacitors based on freestanding Ni-mesh electrode
Authors: Zhao Yaoyao , Jiang Zhouying , Weng Ya , Liu Yan-Hua 
Published: March 2021

Abstract
A high performance transparent and stretchable supercapacitor was formed by the electrochemical deposition of MnO2 on a freestanding Ni mesh and further integrated with an elastic substrate. The solid-state supercapacitor shows a high transparency of 62% at 550nm and superior areal capacitance of 34.8 mF/cm2 at the scan rate of 0.01 v/s. The supercapacitor device possesses a 98.8% capacity retention up to 30% strain. Moreover, the areal capacitance retention rate kept 87% after hundreds of stretching cycles at 30% strain.
Modeling energy system transformation policy in 2020 and 2030: A case study of Shandong Province
Authors: Zhang Xinwen 
Published: March 2021

Abstract
In recent years, Shandong Province has actively adopted policies and measures to reduce fossil energy consumption and achieve clean and low-carbon development. In order to explore the future energy system transformation and upgrading in Shandong Province, this paper use EnergyPLAN model to construct Shandong Province’s 2020 and 2030 energy structure standard scenarios and simulation scenarios for analysis. The results show that: under BAU (business-as-usual) scenario, in 2020, non-fossil energy consumption accounts for 7% of primary energy consumption, but it can only reach 8.67% by 2030, which is far from the policy goal (18%); to achieve the energy consumption goal promulgated by government, three alternative scenarios are then studied. Finally, this paper compares and analyzes the above two scenarios and proposes policy recommendations for the transformation of energy systems in Shandong Province.
Study on three-part pricing method of pumped storage power station in China considering peak load regulation auxiliary service
Authors: Song Xinfu , Zhai Xujing , Chen Weiwei , Xue Jingjie , Wang Pengchao 
Published: March 2021

Abstract
The existing operation mode of pumped storage power station in China has the problems of low profit and unable to fully reflect the value of various auxiliary services. In this regard, this paper puts forward a more reasonable and more suitable price mechanism of pumped storage power station in China. Firstly, this paper studies the pricing method considering dynamic depreciation. Then, on the basis of the feed-in tariff of thermal power units, the avoidable cost method is used to study the pricing method of grid price for pumped storage power station. Finally, based on the efficiency loss cost, generation opportunity loss cost and unit start-up and shut-down cost of pumped storage power station participating in peak load regulation auxiliary service market, a three-part electricity price mechanism is proposed. The electricity price mechanism proposed in this paper is helpful to correctly evaluate the benefit of pumped storage power station and promote the construction and development of pumped storage power station.
How does the urbanization level change in the Yangtze River economic belt, China? A multi-scale evaluation using DMSP/OLS nighttime light data
Authors: Xu Zhiyu , He Xiujuan , Chen Lin , Hu Xunxun , Tang Weiming , Li Jiahui 
Published: March 2021

Abstract
Based on DMSP/OLS nighttime light data, we select the Yangtze River Economic Belt (YREB) as the research area to evaluate the urbanization level of the YREB at provincial, regional, and county scales. First, we construct the compounded night light index (CNLI) based on the nighttime light data by extracting the integrated light intensity (I) and the built-up area (S) of the Yangtze River economic belt from 1992 to 2012, and we respectively calculate the CNLI of the YREB at the province, regional and county scales of the YREB such that we can comprehensively analyze the spatial and temporal distribution characteristics and dynamic changes of the process of urbanization in the YREB. Second, we construct two traditional urbanization level evaluation index models based on socio-economic statistics: The integrated urbanization level index model (IU) and the urbanization composite index model (Cf), which are used to respectively calculate the urbanization levels at the province, region, and county scales of the YREB. Finally, we establish a multi-scale urbanization model of CNLI, IU, and Cf in order to perform correlation analysis of CNLI, IU, and Cf on different scales. The results show that CNLI can objectively reflect the development status of urbanization level, and provide a new index and method for better monitoring the state of urban development and evaluating the annual change of urbanization.
A non-cooperative game theory based energy trading strategy of multi-microgrids
Authors: Liang Jianquan , Wang Panbao , Sun Wei , Zhang Jian , Xu Dianguo 
Published: March 2021

Abstract
This paper proposes an energy trading strategy based on non-cooperative game theory for multi-microgrids (MGs). According to whether the renewable energy generation can meet the load demand, the MGs are divided into consumers and providers. In order to reduce the operation cost, consumers compete to buy the energy provided by suppliers and changing the price of electricity purchase. The suppliers provide energy according to the priority factor. The energy provided by the provider is distributed to the consumer in proportion to the price offered by the consumer, and the income is allocated to the provider in proportion to the sales volume. On this basis, a non-cooperative game model composed of consumers is built, and the game model has Nash equilibrium is proved. Meanwhile, the Nash equilibrium solution through particle swarm optimization (PSO) algorithm is obtained. Finally, the feasibility and effectiveness of the energy trading strategy are verified by simulations.
Quantitative evaluation method of power supply reliability considering voltage sag
Authors: Du Pei , Lin Yan , Zhang Weijun , Liu Zhixuan , Lin Fang , Fang Xiaoling 
Published: March 2021

Abstract
Based on the analysis of the original quantitative evaluation system of power supply reliability, aiming at the influence of voltage sag on industrial users, a hierarchical quantitative evaluation system of power supply reliability considering voltage sag is proposed. The new index system aims to evaluate the reliability of the impact of voltage sag from the perspective of the structure, function and safety of industrial users. The specific evaluation methods are mainly composed of direct loss evaluation, indirect loss evaluation and potential safety hazard evaluation. Direct loss refers to the economic loss caused by the interruption of industrial process after the occurrence of voltage sag. Indirect loss refers to the economic loss caused by defective products due to the imperfect industrial production process. The potential safety hazard refers to the potential safety hazard of the production line where the important equipment is located after suffering voltage sag. This paper focuses on the rationality of quantitative evaluation with the principle of economic equivalence, the significance and internal relations of industrial user structure, function and safety index, and puts forward a reasonable calculation method. Through the case calculation, the layered evaluation results are consistent with the empirical conclusions, with applicability.
A Cournot game model for integrated energy service transaction in electric-gas coupled market
Authors: Gao Xiao , Li Chengren , Zeng Ming 
Published: March 2021

Abstract
Based on the analysis of the game behaviours of multi-energy players, for the purpose of maximining the utility of market entities, this study establishes a Cournot game model in the electricity-gas coupled market for multi-energy players, which include the pricing model of multi-energy players in Leader-Follower mode and the operation optimization model between multi-energy players and local energy system based on Stackelberg game. Through the example analysis, it is demonstrated that the master-slave model has good convergence properties and plays a vital role in the interaction process between different decision-making bodies and find the optimal strategy, which can provide important reference information for the decision-makers and has certain practical value.
Optimal planning method of renewable distributed generation for multiple prosumers participating in distribution networks
Authors: Tan Bin , Qiu Weijie , Ding Yujie , Shi Hujun , Yao Haotian , Shen Xiaodong 
Published: March 2021

Abstract
In the situation that distribution system operator (DSO) and multiple prosumers jointly invest distributed generation (DG) in the distribution network, it is difficult to achieve the balance of multi-agents interests under the requirements of security operation and privacy protection. To solve this problem, an optimal planning method of DG for multiple prosumers participating in distribution networks is proposed. First, the DG planning model of DSO and prosumers are constructed separately, and the network tariff dynamic updating strategy is proposed for the optimal guidance of multi-agent collaborative planning. Then, based on the collaborative planning framework for distributed autonomous decision-making of prosumers and the global coordination of DSO, a distributed solution method is proposed. Finally, the effectiveness of the proposed method is proved through the simulation results, the experiment proves that the network tariff updating strategy can better guide the multi-agent DG collaborative planning, and has better effects in balancing the benefit of prosumers and DSO.
Research on optimal operation strategy of fuel cell vehicle charging-discharging-storage integrated station
Authors: Yang Peng , Yu Xuan , Liu Gaowei 
Published: March 2021

Abstract
The construction of energy supply facilities supporting fuel cell vehicles is the basis for the development of fuel cell vehicles. Aiming at the large-scale environmental protection supply of hydrogen energy for fuel cell vehicles, this paper proposes a construction idea and function setting for a fuel cell vehicle integrated station. Then, an optimized operation model of the fuel cell vehicle charging-discharging-storage integrated station is established. The model takes the total operating cost of the integrated station as the objective function, and considers the power balance and constraints of the electric-hydrogen system in the integrated station. Nonlinear programming tool is used to solve the model. It is verified by calculation examples that the integrated station proposed in this paper can effectively improve the power grid’s peak and frequency modulation capabilities based on the total daily income of ¥25,431, and increase the renewable energy consumption rate from 48.0% to 84.6%.
Project classification and ordering optimization model of power grid company based on entropy weight and improved analytic hierarchy process
Authors: Wang Xi , Ye Qiang , Wang Haiyan , Qiao Yunchi , Cao Yuwei 
Published: March 2021

Abstract
At present, the power grid investment should be developed in the direction of reasonable scale, structure optimization and scientific timing. In this paper, starting from the comprehensive deepening of the precise investment of power grid companies, based on the analysis method of entropy weight order relationship combining subjective and objective, the paper constructs the project evaluation model of power Grid Company with five indicators of policy, urgency, risk, economy and strategy. The model adapts to the requirements of comprehensive policies and development reform, meets the characteristics of regional development, and supports the precise investment control of enterprises. It can ensure the realization of accurate investment in power grid, and give full play to the important role of power grid investment in stable growth, structural adjustment, making up for weaknesses and benefiting people’s livelihood.