bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Seepage Mechanism of Micro Remaining Oil During Cyclic Waterflooding in Low-permeability Reservoir
Authors: Zhou Wei , Yin Daiyin , Zhou Yazhou 
Published: September 2023

Abstract
To explore the flow mechanism of micro-remaining oil during cyclic waterflooding in low-permeability reservoir, the displacement effect of micro-remaining oil under conventional waterflooding and different rounds of cyclic waterflooding was investigated by using a micro-visual displacement experiment based on microfluidics model. The produced ratio of different types of micro remaining oil during cyclic waterflooding was quantified, and major types of micro remaining oils that can be applied effectively during cyclic waterflooding were analyzed. Moreover, the flow mechanism of micro remaining oil during cyclic waterflooding was investigated. Research results demonstrated that clustering type remaining oil and columnar type remaining oil were major types that were applied during cyclic waterflooding. After three rounds of cyclic waterflooding, clustering-type remaining oil decreased by 2.50% on average, and columnar-type remaining oil decreased by 0.81% on average. The major mechanism of cyclic waterflooding is introduced as follows: at intervals of cyclic waterflooding, clustering type remaining oil and columnar type remaining oil exchange with water in pores, throats, and spaces between big and small pores due to the fluctuation of pressure field and effect of capillary force. As a result, oil and water redistribute. Clustering-type remaining oil and columnar-type remaining oil become movable oils.
Grid-connected Inverter Control Strategy of New Energy Microgrid
Authors: Wang Lihao , Liu Jinning , Xie Nengwang 
Published: September 2023

Abstract
The traditional power system is composed of a synchronous generator. Because the rotor of the synchronous generator has the characteristics of the moment of inertia and damping, it can provide or absorb excess energy when the system’s frequency fluctuates. The inertia and damping of synchronous generators determine the frequency dynamic response process of the power grid, which further affects the operation, control, and protection of the whole power grid. However, because renewable energy is connected to the power grid by power electronic equipment, it does not have mechanical inertia and damping characteristics. With the increase of installed capacity of new energy, the whole power system shows low inertia characteristics. In this case, the power grid is more sensitive to interference, which may further lead to load shedding or system instability, or even system collapse. Virtual synchronous generator technology can solve this problem.
The evaluation system for intelligent recycling of cold energy from LNG vessels
Authors: Li Qionglong , Huang Fengru , Lin Xingzhi 
Published: September 2023

Abstract
Through the study of LNG ship cold energy intelligent recycling technology, the analysis of ship propulsion efficiency improvement and LNG cold energy residual energy intelligent recycling is carried out to explore and solve the technical problems of imperfect cold energy recycling in LNG ship cold energy intelligent recycling technology. LNG ship cold energy intelligent recycling uses the combination of dual-fuel propulsion technology and LNG cold energy residual energy recycling technology. The LNG ship cold energy intelligent recycling technology uses various methods such as the direct expansion method, Rankine cycle method of the intermediate medium, and combined method to solve most of the power supply problems on the ship.
The effect of current-carrying friction on the internal crystal phase of diamond coatings on WC-Co substrate
Authors: Cao Chenyi , Chen Naichao 
Published: September 2023

Abstract
A great deal of attention has been paid to friction and wear caused by current-carrying friction. In this study, diamond coatings were deposited on the cemented carbides (WC-Co) substrate by hot filament chemical vapor deposition method. Although the diamond coating possessed a higher roughness than the WC-Co substrate, it was effective at reducing the friction coefficient and improving the effectiveness of WC-Co in the current-carrying friction process. In the presence of 1 A, the diamond coating exhibited a lower friction coefficient than the WC-Co matrix, and the diamond transformed into graphite as a result. The results show that diamond-coated surfaces have a better wear condition than WC-Co.
Experimental Study of Photovoltaic-thermal Integrated Heat Pump Building Heating System
Authors: Liu Chang , Zhang Xiaosong , Zhao Shanguo 
Published: September 2023

Abstract
Photovoltaic-thermal (PV/T) systems and hydronic radiant floor heating systems can enhance energy efficiency and economic viability. This study investigates their integration through experimental research and designs an experiment to test their performance under typical winter conditions. The heat pump system achieves an average COP of 5.66 and an average photovoltaic power output of 107.5 W. The underfloor heating system quickly reaches and maintains 20.47°C with a water supply temperature of 50°C.
The Improvement of Calibration Method of Power Transformer Oil Chromatography Online Monitoring System
Authors: Wang Junhua , Bi Haibo , Shen Tao , Wen Xiaohan 
Published: September 2023

Abstract
When the semiconductor sensors are applied to the power transformer oil chromatography online monitoring system, the error of the traditional linear fitting calibration method exceeds the limit value. Therefore, this paper carries out the research of improving the calibration method of oil chromatography online monitoring system, by calibrating the online monitoring values of seven dissolved gases in reference oil samples using linear function, quadratic function and power function models, respectively. Besides, by evaluating the fitting effect, it is confirmed that the quadratic function fitting result has better correlation and lower fitting error, which is expected to be used to improve the field calibration method of the oil chromatography online monitoring system.
Risk assessment and management system of transmission line equipment above 220 kV
Authors: Zhang Hui , Yu Jiangshun , Yu Rong , Wang Di 
Published: September 2023

Abstract
In this paper, a transmission line operation and maintenance mode based on equipment risk and state is proposed. According to the importance and health degree, the transmission line is divided into two dimensions, which are divided into four levels. By dividing the transmission line risk, which is the consequence after failure, the importance of the transmission line is divided into critical, important, concerned, and general. At the same time, the information management of the above research is realized. It is conducive to the formulation of different levels of line management and control measures. It is also conducive to the optimization of operation and maintenance resources and can improve the efficiency of operation and maintenance.
Diagnosis of Loose Core Fault in Saturable Reactor of Thyristor Valve Based on Vibration Signal Time-Frequency Analysis and CNN
Authors: Wei Xiaoguang , Sun Tianshu , Zheng Lin , Zhang Xiaolong 
Published: September 2023

Abstract
The saturable reactor is one of the core components of the thyristor valve, which plays a role in suppressing current changes and balancing voltage distribution. Due to long-term operation under complex working conditions, the vibration of the reactor can cause the core to loosen. To detect faults in time, a fault diagnosis method is proposed for loose cores in saturable reactors of thyristor valves based on time-frequency analysis of vibration signals and convolutional neural networks. The two-dimensional time-frequency spectrum of the vibration signal is obtained using the short-time Fourier transform method. A convolutional neural network model structure is designed to extract time-frequency spectrum features and diagnose different levels of core looseness faults through learning and training. An experiment was carried out to collect core fault information under variable working conditions. The effectiveness of the method proposed in this paper was verified based on experimental data validation. Through comparative experiments, it was found that the proposed method is superior to existing fault diagnosis methods.
Adaptive control strategy of inertia and damping coefficients based on virtual synchronous generator
Authors: Liu Hanbo , Li Zhuze 
Published: September 2023

Abstract
Virtual synchronous generator (VSG) has been generally concerned in the field of new energy power generation because of their ability to imitate the operational mechanism of synchronous generator. In order to solve the problem of power and frequency fluctuation or even off-limit caused by load changes, this paper summarizes the control strategy for the stable operation of the electricity grid supported by VSG. It combines the changes of various physical quantities in the transient process. It fully uses VSG virtual inertia and damping coefficient flexible and regulable advantages and puts forward an adaptive control strategy for inertia and damping coefficient. The control strategy can efficiently suppress the fluctuation of VSG output power and frequency in dynamic processes. It can cut down the transient adjustment time significantly and promote the stability of the system. The correctness and effectiveness of the proposed control strategy are verified by simulation experiment results.
Hybrid Modulation Strategy for Common-mode Voltage Suppression in Three-level Inverters
Authors: Dong Shiao , Li Yuxin , Dai Wen 
Published: September 2023

Abstract
A hybrid modulation strategy is proposed to suppress the common-mode voltage (V
com) of the three-level PWM inverter on the strength of the SVPWM modulation algorithm (space vector pulse width modulation) for V
com generated during the run of the three-level inverter. The three-level space vector is classified as two different modulation areas by modulation ratios. In the low modulation ratio region, according to the nearest three vectors principle, the spatial voltage vector is obtained by combining the small vector with the medium vector, which suppresses V
com and ensures that only one bridge arm is switched for any voltage vector. In the high modulation ratio region, the vector with large common-mode voltage is discarded, and the zero-vector, medium-vector, and large-vector are selected to synthesize the space voltage vector, which suppresses V
com and ensures the good output current waveform of the PWM inverter. From the simulation results, we can see the hybrid modulation strategy of dividing the region by modulation ratio reduces the magnitude of V
com to 1/6 of the dc bus voltage, and at the same time, a good current waveform is obtained at the output of the three-level inverter.
Hilbert Fractal Antenna for Abnormal Discharge Detection of Transmission Equipment
Authors: Qu Yongjie , Wu Yang , Hei Guoyu , Teng Da , Yan Xinli 
Published: September 2023

Abstract
The safe and stable operation of the power system can ensure people’s basic electricity needs. It also plays an important role in energy security and economic development and can contribute to environmental protection and energy conservation. If there are problems in the power system, it will not only affect people’s normal life and work but also lead to power loss or waste, thereby exacerbating the impact on the environment. With the long-term operation of transmission equipment, insulation devices are aging, leading to frequent abnormal discharges and affecting the safety and stability of the power system. Therefore, timely detection and troubleshooting are necessary. When abnormal discharge occurs in transmission equipment, it will radiate radio frequency (RF) electromagnetic waves, which are mainly concentrated between 200 MHz and 300 MHz. RF antennas that can capture signals in this frequency band can be used for detection to determine whether abnormal discharge has occurred. This article uses the Hilbert fractal antenna as the research object to analyze the impact of different orders on antenna performance and optimizes the different feeding point positions of the antenna. Finally, the antenna structure for detecting abnormal discharge is obtained. By making an actual antenna and conducting experimental analysis, the discharge detection function of the designed antenna is verified.
Parasitic Parameter Prediction for Planar Transformers Based on Neural Network
Authors: Tan Chang , Hong Jianxun , Wu Zihao , Huang Qiuyuan , Wang Cheng 
Published: September 2023

Abstract
Parasitic parameters such as leakage inductance and distributed capacitance of planar transformers have a direct impact on the performance and efficiency of transformers. Traditional methods for parasitic parameter prediction are commonly based on empirical formulas or simulation software, but they have problems of high computational complexity, time-consuming and low accuracy. In this paper, a method for predicting parasitic parameters of planar transformers based on a multilayer perceptron (MLP) under a specific winding structure is proposed, which can improve the efficiency of transformer design. The experiments demonstrate that the model can effectively predict the leakage inductance, distributed capacitance, and AC loss of planar transformers.
The grid simulation device for photovoltaic power generation
Authors: Qian Huifa 
Published: September 2023

Abstract
Solar photovoltaic power generation is the solar radiant energy directly into electricity method, namely the sun radiant energy by solar cells is converted into electrical energy, again through energy storage, control, and transformation, and into people’s dc or ac power that can be used directly. The so-called grid-connected network is simply said to be realized by using the principle of simultaneous operation of voltage, phase, phase sequence, and frequency. The simulation device of its inverter grid-connected is designed, the scheme of simulating grid-connected is given, the drive control system and filter system are designed, and the implementation scheme of the drive control system is introduced in detail. The design and parameter selection of the main circuit and the filter system are given in detail. The hardware and software implementation scheme and circuit structure of the system are given based on DSP. The entire system can meet the requirements of microgrid simulation operation.
Optimization and Performance Improvement of Automatic Generation Control (AGC) for 330 MW Subcritical Thermal Power Unit
Authors: Li Yuanyuan , Hua Zhi , Li Jun , Liu Enren , Gao Song 
Published: September 2023

Abstract
With the continuous assessment of the “Two Detailed Rules”, various power generation groups are paying increasing attention to AGC. A 350 MW subcritical unit has been in a poor performance state under AGC-R mode since the 2022 heating season, with a K1 value below 1.2 and a K2 value not reaching the qualified value. It is facing the cancellation of the qualification for AGC-R mode. In the face of the problem with the unit, this article analyzes three reasons. Firstly, the speed setting exceeds the requirements, but the actual unit action does not meet the standards. There is a deviation in power and a significant deterioration in control quality during the turning point and continuous climbing of AGC instructions. Based on the above analysis, this article proposes three renovation plans to optimize the instructions through nonlinear correction functions and achieve the elimination of instruction deviations. It calculates and judges the difference between the corrected AGC load command value and the actual power value of the unit. It calculates the deviation and sends the deviation to a saturated nonlinear link to generate the feedforward of the main turbine control, improving the output of the main turbine control. By setting a variable integral function, the main control output of the boiler is improved. After this technical transformation, the AGC performance of the unit has been significantly improved.
Flexible On-load Voltage Regulating Transformer by Floating Capacitor Three-level AC/AC Converter
Authors: Wang Ruiqiong , Ke Shengjin , Jiang Xuhui , Zhang Xi , Zhu Yuanhao , Xie Kaiji , Sun Longfei , Yin Jingyuan 
Published: September 2023

Abstract
The flexible on-load transformer can be adapted to different application scenarios by adding different power electronic converter structures through the use of existing transformers. In this paper, a flexible on-load regulator transformer structure based on a floating capacitor multi-level AC/AC converter is proposed, which can compensate the input voltage on the primary side of the transformer in the same direction or the opposite direction, combine with the existing on-load tap-changer, and also achieve fast stepless voltage regulation. Finally, the effectiveness of the proposed new topology is verified by simulation and experiment.
Fuzzy Control Strategy of Tunnel Lighting Based on Input Parameter Optimization
Authors: Li Lanjin , Wang Guo 
Published: September 2023

Abstract
The mismatch between illumination and traffic safety brightness in tunnels leads to much-wasted lighting energy and safety problems. Effective control of tunnel lighting can be achieved by lighting on demand and reducing lighting energy consumption. This paper uses the curve fitting and linear interpolation methods to optimize the luminance reduction factor K proposed in the Highway Tunnel Lighting Rules. It constructs a multi-zone division of traffic speed, traffic flow, and brightness outside the tunnel to obtain the K value under actual road conditions and to establish a fuzzy controller for dimming control. The simulation demonstrates that the proposed strategy can save about 37.38% of tunnel lighting compared to the graded lighting control strategy.
Wireless Charging System with Three Arc-Transmitting Coils for Autonomous Underwater Vehicle
Authors: Cai Bin , Yu Menghong , Lu Haozhou 
Published: September 2023

Abstract
To enhance the misalignment tolerance of the coupling device of the autonomous underwater vehicle wireless charging system, this paper proposes a magnetic coupling device with strong misalignment tolerance. Through the Ansys Maxwell finite element analysis software, it is concluded that, under the dislocation state of the proposed magnetic coupling device, the magnetic field is mainly distributed near the shell wall of the autonomous underwater vehicle. The coupling coefficient change range under the rolling dislocation state is 0.35~0.83, the axial dislocation coupling coefficient fluctuation range is 0.79~0.83, and the radial dislocation coupling coefficient variation range is 0.48~0.83. We design and calculate the compensation network in a wireless charging system and obtain the calculation method of the compensation network. A prototype of that wireless charging system containing arc-emitting coils applied to the AUV has been made, which transfers 48 W power with an efficiency of 87.3%.
Optimal Dispatching of Distributed Generation Cluster Systems Considering Multiply Optimization Objectives
Authors: Feng Ying , Zhu Jian , Kong Bojun , Wang Shengbo 
Published: September 2023

Abstract
In the trend of increasing energy shortages and environmental pollution, integrating clean micro sources as cluster systems has become the mainstream trend in the DG cluster system research field. In an effort to ensure the economy and environmental friendliness of Distributed Generation (DG) cluster systems, a multi-objective optimization scheduling model is established to minimize the operating and environmental costs of DG cluster systems. Based on a multi-objective particle swarm optimization algorithm, this paper conducts a study on the capacity optimal configuration of wind turbines, photovoltaic generators, and energy storage devices. The model proposed in this paper is applied to analyse a DG cluster system in a rural area dominated by agriculture. The results show that the proposed model has a significant effect in reducing the operating and environmental costs of the DG cluster system.
Analysis and Grid Performance Evaluation of Offshore Wind Power Direct Current Transmission System based on VSC and DRU
Authors: Li Haibo , Liu Yushan , Aisikaer  , Lv Hongmei , Wang Yinmei , Wang Xueyan 
Published: September 2023

Abstract
Offshore wind farms, with their abundant and stable wind energy resources, have become the main trend of wind power development in the future. Based on voltage source converter (VSC) transmission technology and diode rectifier unit (DRU) as the hot spot technologies for offshore wind power delivery, they have different characteristics in practical applications. This paper compares the engineering economy of VSC and DRU from the topology of offshore wind power delivery. It combines the key technologies of DRU control. It proposes grid connection performance testing indicators. It builds VSC and DRU offshore wind power DC delivery models, respectively, based on PSCAD/EMTDC simulation software to compare and analyze the operation effects after their faults. The research results show that DRU has a faster response and better support ability than the VSC scheme.
Nonlinear buckling analysis of cat-head transmission tower under strong wind load
Authors: Jiang Heng , Zhu Rui , Wang Zhenguo 
Published: September 2023

Abstract
Based on ANSYS APDL finite element analysis software and B-R criterion combined with displacement equality criterion, the dynamic stability of the cat-head transmission tower is analyzed. In this paper, the static characteristics of the cat-head transmission tower are analyzed first, and the wind load is gradually increased according to the wind speed gradient of 5 m/s. The results show that the cat-head transmission tower cannot be normally served under the wind speed of 45 m/s. In order to analyze the specific instability wind speed of the transmission tower in detail, the nonlinear buckling analysis is used to analyze the cat-head transmission tower. The nonlinear buckling analysis results of the cat-head transmission tower are as follows: the wind speed of instability is V10=43.65 m/s. Therefore, the influence of wind load fluctuation on the dynamic stability of the transmission tower should not be ignored, and the influence of fluctuating wind should be considered in the design of the transmission tower.