bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristic analysis of magnetorheological fluid porous fabric composite with a novel constitute model
Authors: Li Pingyang , Dong Xiaomin , Wang Kaixiang , Ran Jinchao , Yang Baolin 
Published: December 2022

Abstract
As a novel material, magnetorheological fluid porous fabric composite (MRF-PF) has not been further analyzed and modeled. In this paper, mechanical properties of MRF-PF are analyzed quantitatively and qualitatively with a novel constitute model. Considering the wall slip, viscoelasticity and internal porous network of MRF-PF, a constitute model of MRF-PF is derived firstly which can describe the performance precisely. According to experimental results, mechanical properties of MRF-PF are different from conventional MRF. Shear stress τ decreases first, then increases slowly at off-state. Under low magnetic field, shear stress τ presents the opposite variation. It increases at first, and then decreases rapidly. With the further increase of magnetic field, Shear stress τ increases dramatically at high shear rate. This effect is determined by the internal porous network and absorption degree of MRF-PF. A possible flow mechanism of MRF-PF has been proposed. Comparing with different types of MRF-PFs, pre-immersed MRF-PF without relative rotation has a better performance. The maximum shear stress can reach as high as 62.35 kPa with an increase of 22.37% under the magnetic field of 0.7 T. The corresponding dynamic yield stress τ
y
increases to 55.18 kPa with an increase of 26.6%. What is more, internal porous network can support the particle chains to reinforce the shear-resistance property. The shear thinning effect of MRF-PF can be improved significantly. However, MR effect of MRF-PF decreases largely. These attractive mechanical properties make MRF-PF a potential choice for critical engineering applications.
Study of contact conditions at conductor/insulator interfaces used in space charge distribution measurements
Authors: Zheng Lin , Holé Stéphane 
Published: December 2022

Abstract
Interfaces play a major role on charge injection in dielectrics under high voltage. As a consequence, space charge distribution measurements under high voltage may depend on the chosen interface conditions during the tests. In this paper, it is shown that various mountings of an insulating polymer (polyethylene) in a space charge distribution measurement setup develop very different intrinsic dipoles at the interfaces generating in turn an interface voltage that may interact with energy levels between the electrode and the insulator and thus with injection laws. These dipoles are minimal when the insulating polymer has hot-pressed carbon-loaded polymer electrodes or is coupled with silicone oil to carbon-loaded EVA electrodes. On the contrary aluminum coating or direct contact with aluminum in presence of silicone oil for the coupling generates large dipoles compared to gel coupling or with gold coating. The measurements were carried out with an ultra sensible pressure-wave-propagation measurement setup under very low electric field (±30 V/mm at most) for calibration purpose. Aluminum and stainless steel was used for the setup wave-guide in order to check its influence. Interface voltage up to 5 V could be estimated with an uncoated sample in contact with aluminum through silicone oil.
Generalization of the Guendelman nonlinear electrodynamics model
Authors: Mazharimousavi S Habib 
Published: December 2022

Abstract
In this study, we present a generalized version of the specific nonlinear electrodynamic model introduced by Guendelman [PLB640(2006)201] as a result of spontaneously breaking the scale invariance of Maxwell’s linear theory. The generalized model involves a new integer parameter n so that n = 2 reproduces Guendelman’s model. Although with each n in principle there exist a new model but technically only n = 2 and n = 3 yield a closed analytical expression.
Local delivery of tacrolimus using electrospun poly-ϵ-caprolactone nanofibres suppresses the T-cell response to peripheral nerve allografts
Authors: Roberton V H , Gregory H N , Angkawinitwong U , Mokrane O , Boyd A S , Shipley R J , Williams G R , Phillips J B 
Published: December 2022

Abstract

Objective. Repair of nerve gap injuries can be achieved through nerve autografting, but this approach is restricted by limited tissue supply and donor site morbidity. The use of living nerve allografts would provide an abundant tissue source, improving outcomes following peripheral nerve injury. Currently this approach is not used due to the requirement for systemic immunosuppression, to prevent donor-derived cells within the transplanted nerve causing an immune response, which is associated with severe adverse effects. The aim of this study was to develop a method for delivering immunosuppression locally, then to test its effectiveness in reducing the immune response to transplanted tissue in a rat model of nerve allograft repair. Approach. A coaxial electrospinning approach was used to produce poly-ϵ-caprolactone fibre sheets loaded with the immunosuppressant tacrolimus. The material was characterised in terms of structure and tacrolimus release, then tested in vivo through implantation in a rat sciatic nerve allograft model with immunologically mismatched host and donor tissue. Main results. Following successful drug encapsulation, the fibre sheets showed nanofibrous structure and controlled release of tacrolimus over several weeks. Materials containing tacrolimus (and blank material controls) were implanted around the nerve graft at the time of allograft or autograft repair. The fibre sheets were well tolerated by the animals and tacrolimus release resulted in a significant reduction in lymphocyte infiltration at 3 weeks post-transplantation. Significance. These findings demonstrate proof of concept for a novel nanofibrous biomaterial-based targeted drug delivery strategy for immunosuppression in peripheral nerve allografting.
Study on Mixed Match Method of Factory-incoming Coal in Coal-fired Power Plants from the Perspective of Carbon Emission
Authors: Li Hongji , Wang Li 
Published: December 2022

Abstract
In order to better guide the mixed match of furnace-incoming coal in coal-fired power plants from the perspective of carbon emission, according to national carbon emission accounting guidelines for power generation facilities, regardless of the impact of coal storage on coal quality, we have built a coal quality information database for carbon emissions of factory-incoming coal through analyzing the factory-incoming coal source and industrial analysis data on coal quality in a coal-fired power plant as well as using the element carbon content information estimated by soft measurement of element carbon content verified through the test. Based on this, we have constructed the theoretical method to guide the mixed match of furnace-incoming coal, and obtain the optimized mixed match results through the mixed match analysis.
Research on an SAE-based Substation Noise Monitoring Method
Authors: Ma Yuchao , Wang Xin , Jizhong Fang , Qingming Xiao 
Published: December 2022

Abstract
In the area of transformer noise monitoring research, condition monitoring technology based on the combination of AI technology and modern signal processing methods gradually becomes a hot research topic. General pattern recognition methods often have higher requirements for signal acquisition and processing and are often restricted by the limited generalization ability of the models. In order to solve this problem, a sparse autoencoder-based transformer state recognition method is proposed. The sparse autoencoder (SAE) is trained by FFT spectral signals, and the intrinsic features of big data are adaptively refined into simple feature functions. Intelligent diagnosis of transformer conditions is realized by the expression of feature functions. The experimental results show that, compared with BP (backpropagation) neural network and SVM (support vector machine) classification algorithms, this method can quickly and effectively improve the accuracy of transformer state recognition, which is of great significance for industrial development.
Seismic performance analysis of a UHV converter transformer bushing system
Authors: Liu Zhenlin , Xue Zhihang , Lu Zhicheng , Meng Xianzheng 
Published: December 2022

Abstract
A finite element model of a UHV converter transformer was established to study how the seismic response of bushings and the amplification effect of the transformer tank on its bushing, one AC bushing, and two DC bushings. The frequency of DC bushings was smaller than that of the AC bushing, with the first four frequencies being all the modes of DC bushings. The results of stress and displacement response showed that the AC bushing was more affected by horizontal seismic action, while the two DC bushings were more sensitive to Z-direction seismic excitation. Besides, the stress amplification factor was used to evaluate the seismic amplification effect of the transformer tank on bushings.
An Approach of Malware Detection in Power System
Authors: Han Wei , Cai Deyu , Du Xingwei , Ma Weidong , Guo Pei , Wang Feng , Wang Shuzhou , Zhao Zhibo 
Published: December 2022

Abstract
In recent years, cyber attacks against the power industry have occurred frequently, causing huge losses to national infrastructure construction. As an important carrier of network attacks, malware has a great threat to the power system. This paper proposes an E-Gemini model based on the analysis of binary executable files and traditional malware detection techniques. This model was developed by Gemini [1] and has a stronger analysis ability for malware in power systems. This paper also alleviates the problem of the small size of the current power system malware dataset by pretraining and retraining. Experiments have verified the effectiveness of the E-Gemini model. The results show that the proposed model can achieve a maximum accuracy of 89%, which is significantly improved compared to the baseline method.
Pressure changes of nitrogen blanket transformers under internal short circuit faults
Authors: Li Jiansheng , Yang Xiaoping , Wu Yiming , Wang Shengquan 
Published: December 2022

Abstract
The root cause of the transformer fire is an oil tank crack caused by an internal short circuit fault. The gas layer of the nitrogen blanket transformer helps buffer the pressure change caused by the internal short-circuit fault. Moreover, the pressure change simulation is the basis for the configuration of non-electrical protection. This paper analyzes the relationship between the energy and pressure source of the internal short-circuit fault. Based on finite element simulation, the internal pressure transfer model of the transformer is built, and the pressure of the oil tank is obtained. By comparing with the pressure of conventional transformer, the excellent explosion-proof performance of nitrogen blanket transformer is verified.
Study on Vibration Isolation Design Analysis of 500 kV Indoor Substation
Authors: Meng Xianzheng , Gao Po , Liu Zhenlin , Lin Sen , Sun Yuhan 
Published: December 2022

Abstract
In order to study the applicability of isolation technology for indoor substations, this paper establishes a numerical prototype and isolation structure simulation model of a 500 kV indoor substation building structure by using finite element software. Modal analysis and seismic response analysis are carried out to study the dynamic characteristics and seismic response rules of the building for the prototype and isolation structure. The numerical simulation results show that the higher the floor, the more significant the amplification of the acceleration response, and the acceleration response amplification coefficients of the second and third floors are greater than the 2.0 required by the code. The transverse shear force of the first column is reduced by 78%, the acceleration response of the second and above floors is reduced by 80%, and the seismic fortification intensity of the second and above electrical equipment can be reduced by one degree. The maximum displacement of the isolation bearing is 310.32 mm, which is smaller than the limiting displacement of the minimum type of isolation bearing, which is 330 mm. The performance of the isolation bearing is in the safe and stable region, and the isolation design scheme is more reasonable. Compared with the prototype structure, the isolation design scheme significantly reduces the inter-story displacement of each floor, and the concrete frame of the isolation structure is in the elastic region under the earthquake action, which improves the seismic performance of the building and electrical equipment.
Hardware Platform Construction of Hybrid Modular Multilevel Converter Purely Based on FPGA Controller
Authors: Zhang Jianbin , Hao Quanrui , Li Dong 
Published: December 2022

Abstract
The modular multilevel converter (MMC) hardware platform is of great significance to the research of control and protection before engineering operation. In practical engineering, each bridge arm is composed of many submodules (SMs) cascaded, which brings significant challenges to the research. In this paper, a controller based on a field programmable gate array (FPGA) is designed for hybrid MMC, and a hardware platform is built on this basis. The platform fully uses the parallel characteristics of FPGA to improve the calculation speed of the controller. It optimizes the SM capacitor voltage sorting method to shorten the sorting time significantly. The stability experiment verifies that the hardware platform can be applied to the research of hybrid MMC.
SOC Estimation of Lithium-ion Batteries at Different Temperatures
Authors: Chen Yuhang , Xiong Hongjun , Guo Yi 
Published: December 2022

Abstract
With the development of new energy vehicles, an accurate estimation of SOC was crucial for the battery pack’s safe and dependable functioning. Experiments with the NCR18650B lithium-ion battery were made at different temperatures: low temperature (0°C), room temperature (25°C), and high temperature (45°C). A fractional order model and BP neural network algorithm were adopted to estimate the battery charge state of the lithium-ion battery. The experimental findings indicated that the error could be limited to 10% or below, which essentially satisfied the power battery charge status estimate accuracy criterion.
Double-layer Optimization Study of Virtual Power Plants with Source-load-storage
Authors: Yu Changle , Li Wenwen , Liu Nian , Yang Lin , Zhang Su , Wan Jia 
Published: December 2022

Abstract
In order to effectively solve the supply-demand imbalance of the grid caused by intermittent new energy penetration and improve the scheduling flexibility of virtual power plants, a two-layer optimization model of virtual power plants with source-load-storage is proposed. The upper layer of the model is designed to reduce the forecast error of wind power output and improve the revenue of the virtual power plant. On the basis of the maximum wind power consumption, distributed energy storage and fuel cells are used to coordinate and compensate for the deviation between the planned and actual output of renewable energy. The active output of the upper layer is transferred to the lower layer. The lower layer of the model is solved by using the improved linear decreasing inertia weight particle swarm algorithm for the output of the gas turbine unit. The analysis results show that the model can absorb the excess new energy generation in the grid, achieve the balance of supply and demand regulation in the grid, and effectively reduce the economic operation cost of the system.
Reactive Power Compensation Configuration of Offshore Wind Power Based on Economic Differential Pressure Theory
Authors: Chen Meng , Tang Xiaojun , Chen Dezhi , Chao Wujie , Gao Wenman , Yang Daye , Luo Hongmei , Zou Yucheng , Pei Lijie 
Published: December 2022

Abstract
The conventional reactive power balance analysis method for offshore wind power transmission projects can be used to obtain many feasible solutions for reactive power compensation configuration, which requires a large number of simulation calculations to eliminate unreasonable schemes. The work is tedious and lacks theoretical guidance. In this paper, the main influencing factors, such as the current carrying capacity of offshore wind power and submarine cable, the mode of real-time power generation, and the reactive power output regulation of the wind turbine itself, are considered. The reactive power balance of offshore wind power transmission projects is derived. Combined with the economic differential pressure theory, the sea-side and land-side configuration methods of high reactance and dynamic reactive power compensation are put forward. On the basis of realizing real-time reactive power balance, the recommended reactive power compensation configuration scheme effectively reduces the active power loss of the transmission project, and at the same time, lowers the bus voltage of each node at sea, thus reducing the high risk of the excessive voltage of offshore wind farm. This project is supported by the Science and Technology Project of State Grid Corporation of China under “Research on multiple temporal and spatial coordinated optimal control theory for medium and long-distance large-scale offshore wind power transmission system” (No. 5100-202155305A-0-0-00).
Development of Horizontal Vibration-type Synthetic Electric Field Measurement Prototype
Authors: Zhang Zhenyu , Chen Xiufang , Han Haian , Fang Shubo 
Published: December 2022

Abstract
At present, field grinding measurement devices are mainly adopted for DC synthetic electric field measurement. The sensor unit of the device is of a rotating blade structure, and the surface wind generated by rotation causes ion flow distortion, making it difficult to ensure the accuracy of measurement data. In order to optimize the sensing structure of measuring equipment, the vibration-type synthetic field sensing mode was obtained through selection analysis, the horizontal vibration sensor structure and data acquisition hardware circuit structure were proposed, and a vibration-type synthetic field measuring prototype was developed. Through the simulation comparison of the influence of vibration type and field grinding type on the electric field, it can be known that the internal field intensity of the upper and lower 1 mm planes of the equipment shell is basically uniform, and the field intensity of the square and the corner position of the equipment shell are distorted. The electric field distortion of the upper surface of the field grinding device and vibration device is 2.36-8.55 and 1.9-6.84, respectively. The higher the device is, the greater the distortion of the field intensity near the shell, and the distortion of the field grinding type is larger than that of the vibration type. Vibration equipment has less influence on the background field intensity when measuring the ground composite field intensity.
Bi-level Optimization Model of PMU Fault Recovery Based on Observability
Authors: Xue Fei , Wang Xiaoli , Ma Xin , Li Hongqiang 
Published: December 2022

Abstract
Aiming at the failure of PMU caused by cyber-attacks and extreme natural disasters, a bi-level optimization model of PMU fault recovery based on observability is proposed in this paper. By optimizing the sequential restoration of PMU, the control center can maximize the state observability of the system under the condition of limited recovery resources and adjust the power in real time according to the recovered observable nodes, so as to alleviate the power imbalance caused by a disturbance in the recovery process. The upper optimization model takes the maximum observable branch power flow as the optimization objective, and the lower optimization model is constructed as the DC optimal power flow model with the lowest power generation cost. The upper and lower models are coupled by the branch power flow and the node observation state. Then, the lower model is transformed into KKT conditions through Lagrange multiplication, and the nonlinear objectives and constraints are linearized so that the bi-level model can be transformed into a single-level mixed integer linear programming model for solving. Finally, the effectiveness of the proposed strategy is verified by simulation analysis of IEEE39 standard systems.
Dynamic Aggregation Method of Wind Farms with Virtual Synchronous Generator-Controlled Wind Turbines
Authors: Xie Wanying , Qi Xiaoguang , Chen Changsheng , Zhang Qianmao , Tian Jiahui , Zheng Liwen 
Published: December 2022

Abstract
The frequency and voltage dynamic processes of each wind turbine in the existing wind farm are different, and the available aggregation model of wind farms mainly focuses on the steady-state output power, lacking an effective dynamic aggregation mechanism. Wind turbines usually adopt the virtual synchronous generator method (VSG) to simulate the external characteristics of the traditional synchronous generator. Its frequency dynamic response is mainly affected by the virtual inertia and damping parameters, and the excitation regulator parameters determine the voltage dynamic response. Therefore, the aggregation method of the traditional synchronous generator is also applicable to such wind turbines. Firstly, the dynamic characteristics of the points of wind farms’ point of common coupling (PCC) are discussed. Then, the dynamic aggregation method of the VSG-wind farms is proposed based on the Kuramoto (KM) model and the small signal analysis of the wind turbines. Finally, a wind farm consisting of multiple VSG-wind turbines under disturbances is simulated in PSCAD/EMTDC to verify the effectiveness of the proposed dynamic aggregation method.
Research on DC Line Protection Method of Large PV Plant Based on Transient Direction
Authors: Zhang Yan , Zhu Yongqing , Zhang Zhaofeng , Zhang Pengcheng , Huang Yuhui 
Published: December 2022

Abstract
Due to the complex fault transients associated with DC convergence in photovoltaic (PV) plants and the large number of power electronics used in systems, the protection device is unable to determine the location of faults, and thus the protection is inadequate. This paper proposes a protection scheme for the DC system of a large PV plant. The accurate model of the PV plant is built in consideration of the DC system, including the current limiter. The differential voltage and current are utilized to realize the location of the fault section. The voltage transients are used to locate the fault within the section accurately. Study cases in PSCAD/EMTDC show the proposed protection scheme is effective and practically useful for PV plants.
Research on ultra-reliable and low-latency secure transmission of distribution monitoring communication system
Authors: Li Ruide , Dai Wenxia , Zhang Haomin 
Published: December 2022

Abstract
In the smart distribution network scenario, we investigate the physical layer security performance of power line communication in FBL. The results show that the system secure transmission rate increases with increasing channel block length and eventually converges to a constant value. Compared with the traditional SE maximization algorithm based on FBL, the total secrecy rate is improved by about 13%. Compared with the traditional linear precoder (ZF), the secrecy rate is improved by about 30%. Therefore, the proposed scheme is superior in supporting the power line communication system based on FBL.