bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transformer Oil Temperature Variation Based on Terahertz Time-domain Spectroscopy
Authors: Luo Guofang , Wei Xiaochuan , Liu Ping’an , Li Wenping , Li Yingze , Zhang Zhixiang , Zhou Kuan , Shao Zuoshan , Wang Dong 
Published: August 2023

Abstract
The transmission terahertz time-domain spectroscopy system is used to measure the transformer oil terahertz spectrum at different temperatures, the time and frequency domain, time delay, and refractive information of transformer oil with different temperatures are tested. The terahertz wave of the time-domain delay of transformer oil at different temperatures is obtained, the variation of time-domain delay and refractive index with different temperatures in the terahertz band were calculated and the linear variation trend was fitted.
The characteristics of positive corona discharge at different altitudes
Authors: Liu Jiqiu , Wei Hongyu , Lv Duo , He Wangling , Wang Yanzhao , Wan Baoquan , Gan Zheyuan , Zhou Yang 
Published: August 2023

Abstract
With the vigorous growth of UHV transmission projects, transmission lines crossing high-altitude areas are inevitable, and the degree of corona discharge in high-altitude areas is more intense. The electromagnetic environmental problems caused by corona discharge have gradually become one of the key technical problems restricting UHV transmission in high-altitude areas. To investigate how height affects the positive polarity corona’s corona characteristics, using the movable small corona cage to carry out experiments at four altitude points in the range of 1120 m–4320 m, and measures the corona current pulse and radio interference level of 0.8 mm diameter fine copper wire under different positive voltages. Several conclusions can be drawn from the data analysis, including the following: The average current pulse amplitude grows with altitude, first before decreasing, and the current pulse repetition frequency rises along with altitude. The major conclusions of this essay can serve as a starting point for the study of the corona effect.
Research On Multi-source Collaborative Distribution Network Fault Recovery Technology
Authors: Liu Huaxia , Xu Yan 
Published: August 2023

Abstract
When a power outage occurs in the power system, multiple distributed power sources and energy storage systems connected to the distribution network can be coordinated to restore power to important lost loads in a priority and fast manner. However, the generation output of intermittent power sources such as wind and photovoltaic is uncertain, which makes it difficult to provide a continuous and stable power supply to the loads in isolated islands. In this paper, we first explore the improvement effect of multi-source cooperative fault recovery on distribution system resilience, consider the distribution system with distributed power sources, energy storage systems, and controllable loads, and propose a distribution system recovery model with the goal of maximizing the power consumption of the restored loads for a relatively short period of time after a power outage incident. Then, the power output characteristics and power supply capacity of various distributed power sources are analyzed, and the intermittent power output fluctuations are compensated using controllable loads. Finally, the proposed model and method are validated using a modified IEEE 33-node distribution network as an example.
Voltage Management of Distributed Photovoltaic Cluster Connected to a Distribution Network
Authors: Yang Shuangshuang , Zhang Ganghong , Gao Jian , Yuan Jianan 
Published: August 2023

Abstract
The proportion of distributed photovoltaic grid connection in the distribution network is gradually increasing, and its characteristics of high volatility and poor stability have brought new challenges to the overvoltage problem faced by the distribution network structure and safe and stable optimization operation. This paper mainly studies clustering and reactive power optimization control of distributed Photovoltaic. The system architecture of the cloud edge is constructed, and the voltage autonomy strategy within the region after partition is proposed. The model is established with the total voltage offset and the minimum line loss as targets. Adopting adaptive PSO-BP algorithm model for optimization solution. Finally, conduct simulation analysis on the MATLAB platform. We can see that the proposed method can not only reduce the uneven voltage distribution, network loss, but also reduce the calculation burden of the controller has a positive effect.
Phase-angle adaptive current differential protection for active distribution network
Authors: Ni Pinghao , Cao Hao , He Jinghan , Li Meng , Gao Fengxi , Wang Ziqi 
Published: August 2023

Abstract
With the distributed generator to be attached to the distribution network, the current differential protection scheme may have some problems, resulting in maloperation or rejection of protection. This paper investigates the current distribution properties of an active distribution network with branches of undetected load and draws the conclusion that undetected load may cause differential protection maloperation. The differences in fault properties of differential protection in transmission network scenarios and distribution networks containing distributed generator are evaluated, leading to the conclusion that differential protection applied to active distribution networks may have reduced resistance to transition resistance and that poor signal synchronization conditions in distribution networks may lead to larger synchronization errors. A phase-angle adaptive current differential protection is proposed. It adaptively adjusts the phase angle constraint using the magnitude of the power frequency full current component proportion at both sides of the line. It can accommodate the protection needs of various operation modes of distribution networks containing distributed generator, and has the characteristics of strong resistance to transition resistance and strong phase shift braking ability. The correctness of the suggested protection scheme was verified using the PSCAD platform.
Simulation-based Multi-unit Collaborative Optimization in Data Centers
Authors: Liu Zhiqiu , Song Jiaqi , Li Rui 
Published: August 2023

Abstract
With the rapid development of information technology in China, the problem of energy conservation in data centers has become increasingly prominent, and the green data center model is inevitable. The refrigeration equipment which is the main power consumption in the data center is affected by the environment, room temperature, unit output, and other factors. This paper provides a scheme of multi-unit collaborative optimization cooling. It is mainly divided into four stages: first, a model of the data center is built through Modelica, and it is exported as a fmu file. Second, the PSO optimization strategy is used to generate the data sets which contain unit output and cooling effect at different times. Third, LSTM and TCN load forecasting models are trained. Finally, through a comparison of various optimization algorithms, the PSO-LSTM-TCN model is used to simulate the unit output and optimize the output parameters of multiple units.
Large-signal Stability Analysis of Grid-connected DC Microgrid with VSC
Authors: Wu Ying , Xu Yonghai , Wang Yingxin , Chen Lin 
Published: August 2023

Abstract
The grid-connected DC microgrid under the background of high penetrations of renewable energy sources and high penetrations of inverter-interfaced devices has the characteristics of strong nonlinearity and poor immunity, which leads to the problems of large-scale voltage fluctuation and instability when the grid-connected DC microgrid suffers large disturbances, and it seriously influences the security and stable operation of the system. Therefore, a large disturbance stability criterion which is based on the mixed potential theory (MPT) for the DC microgrid model with a grid-connected voltage-source converter (VSC) is proposed. This paper also analyzes the mechanism of the conservatism of the stability criterion, verifies the accuracy of the large disturbance stability standard, and analyses the influencing elements and basic mechanism of the large-signal stability (LSS) of the nonlinear systems, which provides a benchmark to design the parameters of the control of VSC and main circuit. Finally, the effectiveness and accuracy of the analysis are verified by electromagnetic transient simulation.
Suppression Strategy of Differential Mode Circulating Current in Parallel Three-Phase PWM Converter
Authors: Wang Lianzhong , Cao Yifan , Liang Xiaobin , Jiang Xinjian , Li Tao , Zou Qifeng 
Published: August 2023

Abstract
Parallel three-phase pulse width modulation (PWM) converter is a useful technique for increasing the capacity of a power system, but it also introduces the issue of circulating current, which can cause an increase in the loss of power electronics (PE) switches and even lead to over-current, which can affect the overall performance of the system. In this paper, a strategy is proposed for suppressing the differential mode circulating current (DMCC) in each phase of the parallel converter, which is less dependent on system parameters. Based on the mathematical model of the parallel converter, the relationship between the PWM duty cycle and circulating current is derived, which provides a basis for adjusting the switching operation of PE switches. This method requires no additional hardware and is simple to implement with a fast dynamic response. The simulation results verify the correctness of the theoretical analysis, and it can effectively achieve the balanced suppression of DMCC in each phase, which indicates that the method is suitable for the application scenario of parallel current sharing of multiple converters.
A Time-sequential OPF Simulation Method for Renewable Utilization Studies Considering Energy Storage
Authors: Zhang Zhenmin , Cai Wenbin , Wang Yuan , Lu Haixia , Li Ye , Li Qinmiao 
Published: August 2023

Abstract
In recent years, renewable generation, especially wind, and solar have become one of the major generation resources in electrical power systems. Due to the non-dispatchable feature of renewable generation, curtailment occurs when the rest of the system is not able to accommodate the maximum renewable output. To analyze the curtailment in the system planning stage, however, traditional studies such as the production simulation method are limited to identifying accurate curtailment rates since the time resolution is sparse and grid topology is omitted. Therefore, in this paper, we propose a time-sequential optimal power flow (TSOPF) simulation method for studying renewable utilization. This method supports second-level temporal simulation which is fine enough to capture the fluctuations of renewables. In addition, the energy storage is incorporated in the simulation to reflect its impact on facilitating renewable utilization. The proposed simulation method is tested based on a real provincial power grid with historical time-sequential data of system load and renewable.
Unit commitment with AC optimal power flow constraint
Authors: Liu Shiqi , Wang Haoyi , Lu Zheqin , Dong Jizhe 
Published: August 2023

Abstract
Because of the enormous economic gain it may offer, unit commitment (UC) has been a primary optimization job in the daily operation planning of contemporary power systems. The AC optimal power flow (ACOPF) constraint is a method for determining the ideal load arrangement in alternating current (AC) power systems. Using unit commitment and ACOPF limitations to determine optimal load distribution is an important approach to ensure the steady functioning of power systems. The unit commitment approach with ACOPF constraint is examined in this study. The aims and contents of the study are set by analyzing the current approaches, and a piecewise linearized unit commitment method is developed that takes into consideration the ACOPF limitations and has good accuracy and practicality. Finally, to validate the method’s effectiveness, it was tested using a six-bus test system.
Two-stage Short Circuit Current Method Based on New Energy Source Fault Characteristic Fitting
Authors: Du Bowen , Guo Haiyi , Jiang Tong 
Published: August 2023

Abstract
A large number of full-power inverter type new energy sources are connected to the power grid, resulting in a large error in the traditional power grid short-circuit calculation method. By analyzing the relationship between the output current of full-power inverter type new energy sources and the voltage at the parallel point, a two-stage short circuit current method based on the fitting of new energy source fault characteristics is proposed. In the first stage, the polynomial fitting method is used. The piecewise function expression of the new energy source output current is fitted into a continuous derivative curve. In the second stage, the original output characteristic function is correspondingly replaced with the fitting function in the first stage. In each iteration process, the output short-circuit current of the new energy source is corrected according to the current new energy grid-connected node voltage until the convergence conditions are met. The feasibility of the proposed method is verified by the analysis and simulation of an IEEE 15 node example system. This method can be applied to solve the short-circuit current of the power grid with a full-power inverter type new energy source.
The coordinated control strategy of DC microgrid based on multiple energy storage units
Authors: Wang Chenxia , Xie Jiayu , Wu Zhiquan , Zhang Xin , Li Yingying , Song Huihui 
Published: August 2023

Abstract
Recently, the DC microgrid (MG) has caught people’s attention because of its simpler control system than the AC microgrid. In this paper, the bus voltage layering control method based on droop control is used for DC microgrid coordination control. According to the working characteristics of the DC bus, the voltage of the DC bus is divided into five sections, corresponding to 5 operating modes respectively. Inside the DC microgrid, each unit converts the operation mode by local control according to voltage amplitude. The photovoltaic power generation unit adopts MPPT control and constant voltage control to adjust the running point tracking, so as to realize changing-over smoothly between voltage regulator mode and MPPT. The battery system adopts a hierarchical operation control method of several batteries on the basis of the state of charge (SOC). To realize the target, which means getting rational active power allocation and SOC equilibrium of each battery unit, as well as different batteries changing-over the charge and discharge modes on the basis of SOC size, so as to adjust the droop curve according to the power size. Finally, the balance between the three objectives of the highest photovoltaic energy utilization rate, energy storage SOC balance, and stable bus voltage is achieved.
Operating State Evaluation Method of UHV Oil Immersed Shunt Reactors
Authors: Gu Zhaoliang , Gu Chao , Li Zhen , Zhu Wenbing , Zhu Qingdong , Li Longlong , Wang Jian , Wang Haozhe 
Published: August 2023

Abstract
The oil-immersed shunt reactor is one of the most important reactive power compensation equipment in the ultra-high voltage (UHV) long-distance transmission and transformation system, which can solve the problem of large power and long-distance transmission that makes the capacitance effect of transmission lines obvious. At present, the commonly used state evaluation methods for UHV oil-immersed shunt reactors are mostly based on a certain factor or several factors to make judgments, without a comprehensive consideration of the overall operating condition information of the shunt reactors. There are various uncertainties in the process of fault diagnosis and state evaluation of the shunt reactors, and the accuracy and timeliness of the diagnosis results are poor. To solve the above problems, this paper combines the key characteristic parameters of oil immersed shunt reactor, such as vibration, chromatography, partial discharge, and oil temperature, and establishes a comprehensive evaluation method for the operating state of oil immersed shunt reactor based on Gaussian Cloud Model (GCM), and verifies its effectiveness through test data, whose R2 over 0.98. The test data show that this method can effectively judge the operation state of the UHV oil-immersed shunt reactor, which accuracy rate of state diagnosis is over 91%. The results of this paper can provide technical support for the application of UHV oil-immersed shunt reactor state assessment and diagnosis, and further improve the level of equipment operation and maintenance.
Localized Equipment Calibration Technology for Substation Relay Protection Considering Electromagnetic Interference
Authors: Chen Jianpeng , Yang Mingze , Shi Yongjun , Yao Bin , Yun Zhenxing , Li Qinghong 
Published: August 2023

Abstract
At present, the conventional localized equipment calibration technology mainly adopts the manual way to check the equipment parameters, which leads to low calibration accuracy due to the lack of analysis of the calibration error sources. In this regard, the localized equipment calibration technology for substation relay protection considering electromagnetic interference is proposed. The calibration error value is calculated by simulating a high-precision localized equipment unit, designing the pre-circuit for fast voltage and current sampling, and analyzing the calibration error source. The experimental results show that the proposed calibration technique can effectively reduce the delay characteristic error value of the equipment and has a high calibration accuracy. The delay characteristic error of the average calibration is lower than 23%.
An LSTM-PSO-Based Predictive Strategy and Its Application in the Main Steam Temperature Control in Power Plants
Authors: Jin Fei , Hao Xiaoguang , Yin Zhe , Yang Chunlai , Liu Xuelai , Shi Yijun 
Published: August 2023

Abstract
We proposed an LSTM-PSO predictive controller strategy to overcome the large delay and strong disturbance during main steam temperature control. First, the long short-term memory (LSTM) network model was developed to forecast the future trend of mainstream temperature, and the deviation between the model output and the expected value after feedback correction was minimized by the particle swarm optimization (PSO) algorithm. Then, the LSTM-PSO predictive controller was taken as the primary controller to maintain the steam temperature of the coal-fired boiler. A comparative simulation with conventional PID cascade control and dynamic matrix controller strategies was given, and the test calculations indicate that the adjustment time was shortened and the overshoot was reduced. Finally, the LSTM – PSO predictive control strategy was deployed into the actual boiler operation process of a 300 MW coal-fired power plant, within 0.5 °C steady-state error and 2 °C dynamic error.
First-principles Study of the Structural Properties of RbSnI2Br Perovskites Under Pressure
Authors: Liu Xin , Zhang Suyun , Deng Pengcheng , Li Haoning , Zhao Yifen 
Published: August 2023

Abstract
As a member of lead-free perovskite, tetragonal phase perovskite RbSnI2Br has a long-term development prospect. Due to the effect of structural changes on physical properties, we have explored the pressure-induced phase transition of RbSnI2Br perovskite. For this project, the structural properties of the tetragonal phase perovskite RbSnI2Br are studied by using the Perdew-Burke-Ernzerhof (PBE) functional for the generalized gradient approximation (GGA) under pressure conditions of 0 GPa–1 GPa. The calculation results of structural factors were in excellent agreement with those obtained from previous studies at the ground state, which ensures the accuracy of the study. The results show phase transitions occur with increasing pressure. The structural space group of β-RbSnI2Br changes from P4/MMM (tetragonal system) to P1 (triclinic system) under pressure in the range of 0 GPa–1 GPa. All these provide a relative theoretical basis for our further understanding of α-RbSnI2Br perovskite.
Adaptive control of DFIG-based wind turbines for fault ride-through and reactive power support based on stator current transient component
Authors: Wang Jianing , Fu Yuan , Zhang Xiangyu 
Published: August 2023

Abstract
The fault ride-through performance is improved through the control of the transient components of the stator current. The reactive power provided by the DFIG within the margin of the converter can significantly enhance the grid-connected safety of the DFIG. Firstly, the reasons for the fault overcurrent of the DFIG’s rotor are analyzed. Secondly, according to the operating conditions of the wind turbine, the reactive power support limit of the DFIG-based wind turbines based on the stator current transient component control is analyzed, and an adaptive reactive power support control suitable for fault ride-through is proposed to maximize its support potential for grid-connected voltage. Finally, the DFIG can not only suppress the rotor overcurrent through the transient component of the stator current but also have a reactive power support capability that is superior to the grid-connected standard.
Suppression of voltage gain fluctuation in LLC Resonant Converter Based on chaotic spread spectrum
Authors: Liu Hong , Kong Fan-nie , Chen Yan-Ming 
Published: August 2023

Abstract
In order to realize the voltage stable output of the LLC resonant converter under different loads, a voltage gain fluctuation suppression technology of the LLC resonant converter based on a chaotic spread spectrum is proposed. The gain fluctuation electromagnetic interference signal is eliminated by the Chua’s circuit; The rated voltage value is discretized, and the target network and the evaluation network are used to form a deep Q network, with the multi-threshold judgment method and the variable step method respectively completed the gain fluctuation suppression target under different working conditions. The experimental results show that the proposed technology can achieve stable voltage output in both dynamic and steady-state conditions, with good gain fluctuation suppression effect and strong timeliness. It provides data reference for the rational application of the LLC resonant converter.
Research on Intelligent Terminal Based on Distribution Multi-service Integration under The Dual-carbon Target
Authors: Chen Zhijun , Zhou Chunli , He Chengyu , Lin Xiqiao , Qin Huiling , Cheng Min 
Published: August 2023

Abstract
The distribution network is used to distribute electric energy in the power system, which can reasonably allocate resources according to the power demand of different users. Intelligent terminals for distribution multi-service integration mainly include a distribution switch monitoring module, distribution transformer monitoring module, concentrator, gateway, and main controller. Firstly, the current, voltage, and power of electricity are collected by setting monitoring points in the distribution network and installing current transformers, voltage transformers, and energy meters. The collected data are processed by the distribution transformer monitoring module to improve the effectiveness of the data. Finally, the processed data are sent remotely through the main controller and gateway. By designing a four-in-one intelligent terminal device for distribution multi-service integration, it can monitor power equipment and collect power consumption information of different users, further excavating the potential value of power data, which has practical significance for the improvement of energy utilization efficiency.