bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-scale analysis of global electromagnetic instabilities in ITER pre-fusion-power operation plasmas
Authors: Hayward-Schneider T. , Lauber Ph. , Bottino A. , Mishchenko A.
Published: May 2022

Global electromagnetic gyrokinetic simulations are performed with the particle-in-cell code ORB5 for an ITER pre-fusion-power-operation plasma scenario, with half-field (2.65 T) and half-current (7.5 MA). We report on a ‘multi-scale‘ analysis of the discharge, considering eigenmodes and instabilities across three scale-lengths (n < 35, 45 < n < 70, n > 100). Although the scenario will nominally have neutral beam heating with particles injected with 1 MeV, Alfvén eigenmodes are investigated in the absence of such source, and reversed shear, toroidal and elliptical Alfvén eigenmodes are found with weak damping for moderately low toroidal mode numbers (10 ⩽ n ⩽ 35). At higher toroidal mode numbers (40 ⩽ n ⩽ 70), unstable Alfvénic modes have been observed close to rational surfaces and are labelled as beta-induced Alfvén eigenmodes (BAEs)/Alfvénic ion temperature gradient modes, since their frequency is associated with the BAE gap and they are driven by the bulk plasma on the Alfvénic continuum. These modes are unstable in the absence of energetic particles (EPs), and adding a species of EPs (with an isotropic 1 MeV slowing down distribution) has negligible impact on their growth rate. At higher toroidal mode numbers (n ⪅ 200), low frequency microscale instabilities are observed.
Rheology of a granular system with capillary interactions
Authors: Montoya-Reyes Susana , Sánchez Rodrigo
Published: May 2022

The rheology of granular systems is poorly understood, particularly in terms of single-particle behaviour. The present work examines a computational system with capillary interparticle interactions, mimicking granular particles at an interface. Depending on the detailed physics of the system, Newtonian or viscoelastic behaviour is observed; the latter case corresponds approximately to the Voigt model of a fluid. This behaviour hints at analogies with thermal systems.
A smoking behavior detection method based on the YOLOv5 network
Authors: Jiang Xiangkui , Hu Haochang , Liu Xun , Ding Rui , Xu Yuanbo , Shi Jianxu , Du Yaoyao , Da Chunlin
Published: May 2022

Smoking in public places not only brings about some safety hazards, but also does harm to people’s lives, property and living environment. A smoking behavior detection model based on deep learning is trained for the concern of environment and safety. First, a vertical rotation data enhancement method is adopted in the preprocessing stage to extend the dataset and increase the objects of detection. Then, the channel attention module is introduced in backbone network to calibrate the feature response. Finally, added a small target detection layer to the YOLOv5 algorithm. This paper analyzes the network structure of the YOLOv5s, and the model is trained and tested by utilizing the YOLOv5s network. Experimental results show that the mAP value of the algorithm is improved by 5.3% over the original algorithm.
CAN message unpack and pack based on simulink automatic code generation technology
Authors: Yuan Ruiteng , Xiao Chun , Liu Mengjie , Chen Jing , Yu Maochang
Published: May 2022

Aiming at the problem of a large amount of CAN communication message data of automobile controllers and low efficiency of traditional software development, this paper proposes a method of CAN message unpack and pack based on Simulink automatic code generation technology. S-Function is used to design CAN message sending and receiving model that can import DBC files, and use RTW (real-time workshop) to realize Simulink model to automatically generate C code. This method effectively solves the unpack and pack of CAN messages, simplifies the code development process, and improves the efficiency of software development, especially when there are DBC files, which simplifies the work of sending and receiving and testing.
Dimensionality reduction method of rotor fault data set based on KPCA-KNPE
Authors: Lu Yu , Wu Han , Zhou Bo
Published: May 2022

In order to solve the problem that it is difficult to extract fault information in all directions in the process of dimensionality reduction of high-dimensional and nonlinear fault data sets, this research designs a rotor fault data set that combines Kernel principal component analysis, KPCA and Kernel Neighborhood Preserving Embedding, and KNPE Dimensionality reduction method. This method first uses the KPCA algorithm to effectively reduce the redundant attributes of the data, and retains the global nonlinear information of the original data; then uses the KNPE algorithm to mine the local manifold structure information of the data and extract the low-dimensional essential features. The above method can avoid the distortion of the local subspace structure through the simultaneous orthogonalization process, and can visually display the low-dimensional results. Use low-dimensional feature subsets to input K-nearest neighbor, KNN recognition rate and cluster analysis, etc. The distance GB
and the intra-class distance GW
are used as indicators to measure the effect of dimensionality reduction. Experiments show that this method can fully extract global and local discriminant information, make the fault classification clearer, and the recognition accuracy rate has been significantly improved. The research can solve the visualization and classification of high-dimensional and nonlinear mechanical fault data sets, and provide theoretical reference.
Robust stabilization technique for a quadrotor slung-load system using sliding mode control
Authors: Sun Huiyu , Gu Xinyan , Luo Shaoxin , Liang Yuan , Bai Jing
Published: May 2022

This paper addresses the problem of the robust stabilization control for a quadrotor slung-load system using sliding mode control. The hybrid model of the slung-load system is presented as two separate systems, one fully actuated, and another under actuated. To achieve the robust stabilization control with the unexpected external disturbance, a sliding mode controller is proposed to enforce the slung-load system tracking of the desired trajectory with a slight swing of the suspended load. The Lyapunov function is defined as the system energy function that is always dissipated over time until nullity, when the system reaches the point of equilibrium. The stability of the controller is analyzed by the Lyapunov function and the stability criteria are given. Finally, the simulations are performed to evaluate the effectiveness of the proposed control scheme.
A data-driven innovative design method for smart product-service systems to achieve mass personalization in rehabilitation
Authors: Ren Mengyang , Xiang Zhongxia , Cong Jingchen , Nan Bin
Published: May 2022

Smart product-service system (Smart PSS), as an emerging digital paradigm, offers users solution bundles to enhance the digitalization capability of the system by utilizing user-generated data. Massive information can be collected to investigate the dynamic changes of user requirements and assists the developers in designing personalized products and services. Meanwhile, key technologies (i.e. big data analysis and cloud computing) have enabled upgrading the rehabilitation equipment from the traditional physical training device to the personalized smart rehabilitation product-service system. However, few studies focus on gathering and utilizing user-generated physiological data to guide the innovative design of rehabilitation solutions in the Smart PSS environment. To fill this gap, an innovative design method is proposed to guide the Smart PSS development in the personalized rehabilitation field. The presented approach can be divided into three phases: the research phase, the development phase, and the usage phase. A personalized lower limb rehabilitation smart product-service system was described to explain the proposed approach.
Control algorithm of path planning and path tracking for automated valet parking
Authors: Kong Qi , Zhang Liangliang , Xu Xin
Published: May 2022

Automated Valet Parking (AVP) can relieve drivers from having to park. It enables vehicles to drive, park and charge fully automatically. This paper focuses on the first working step of the motion planning module, the global path planner. Therefore, a global path planner will be developed and evaluated based on actual research methods. A route will be computed by using an A^* algorithm based on the occupancy grid map. Subsequently, a smoothing operation will follow to obtain a drivable path. By implementing a single polar polynomial function each vertex is smoothened. The resulting global path serves as an input for path tracking. For a reasonable simulation, a vehicle controller with a lock-ahead distance and a node-check will be designed in order to keep the vehicle on the desired path. A simulation of the designed components in CarSim will be carried out to analyze the path tracking and vehicle behavior in detail.
Influence of pyrolysis temperature on tea waste-based biochar property and function as a heavy metal sorbent in aqueous solution
Authors: Cui X. L. , Zhong J. , Li H.X. , Jin R.Z. , Liu Y. , Che X.K. , Yuan X. T. , Zhang Q.D. , Fu H.
Published: May 2022

The properties of biochars and their adsorption performance are highly dependent on the pyrolysis temperature. In this study, tea waste-based biochars at the different pyrolysis temperature (573K-973K) were investigated, and adsorption capacities of heavy metals from solution by biochars were studied. TG/DTA and SEM results showed that with the increased of pyrolysis temperature, the yield of biochar sharply declined and reached stable at 973K. Moreover, low ratios of H/C, O/C and (O+N)/C were obtained at high pyrolysis temperature, which could produce more pore structure and be conducive to the adsorption of heavy metal ions. The adsorption experiments confirmed that the Pb and Zn absorption efficiency at 973K could reach 99.98% and 30.49%, respectively, which was the optimum temperature.
The application of CFD technology in the research of inorganic ceramic film
Authors: Li Xin , Fan Zimin
Published: May 2022

Inorganic ceramic membrane has been widely used in the field of fluid filtration, purification and separation. The flow characteristics of fluid passing through ceramic membrane are very important for its filtration and purification efficiency. Computational fluid dynamics (CFD) technology can simulate the fluid field rules and predict its application effect, so as to optimize the membrane structure and performance. This paper reviews the application of inorganic ceramic membrane and the application of CFD technology in the optimization of the structure of the inorganic ceramic membrane module and filtration purification separation, and makes a prospect for its future development.
Influence of structural size on mechanical properties of nitinol left atrial appendage occluder
Authors: Zhao S. , Li H. , Guo P , Li C. , Kong Y. , Song Y. , Guo L.
Published: May 2022

Left atrial appendage occlusion is one of the effective measures to prevent left atrial appendage thrombosis and reduce embolism. The structural size of left atrial appendage occluder has an important influence on its mechanical properties and may further affect its effectiveness. In this paper, the diameter shrinkage of nitinol left atrial appendage occluder with different structural sizes under different forces was studied by finite element simulation to evaluate their mechanical properties. It was found that the diameter shrinkage of left atrial appendage occluder of different structural sizes raised with the increase of the applied force. Reducing the width of the auxiliary support part of left atrial appendage occluder could improve the overall flexibility of left atrial appendage occluder although the rigidity of the main support part was slightly reduced. In addition, when the shrinkage rate of the main supporting part was the same, the flexibility of the auxiliary support part was improved. The results may provide a theoretical reference for improving the design of left atrial appendage occluder.
Experimental study of AA5052-H32 al alloy in single point incremental forming process, SPIF
Authors: Bhandari Krishna Singh , jung Dong won
Published: May 2022

Forming a sheet in a normal room temperature is a famous method of reshaping a metal. To avoid the fracture, proper selection of a metal, sheet thickness and purity of metal are considered. So, research considering the parameters along with spring back are discussed throughout the paper. A 0.5mm thickness sheet is being formed by using Single point incremental forming process, which is also known as SPIF. From SPIF a 0.5mm sheet is formed in three degree. I.e., 30°, 60°, and 90° as in fig 1. The experiment was performed to evaluate the maximum height of 0.5mm sheet to improve formability. For this, the use of lubrication, grease and oil were mixture and applied in a sheet. Overall, the present of spring back is observed and reduced in a sheet while applying mixed lubrication. While forming a sheet, the thinning behaviour in is witnessed with the smooth surface of a metal sheet.
Study on quality of low alloy high strength steel Q345 weldment
Authors: Hu Min
Published: May 2022

In this paper, the temperature, microstructure, residual stress and welding deformation of typical welded joints of low alloy high strength steel are calculated by using the finite element software SYSWELD. The temperature, microstructure and residual stress of Q345 low alloy high strength steel welded joint by single pass remelting and two pass remelting were numerically simulated, and the accuracy of the finite element model was verified by experiments. The numerical simulation results based on Satoh model show that the formation process and evolution mechanism of residual stress in Q345 steel at different hot temperatures. The single pass remelting weld of Q345 steel is mainly bainite with an average hardness of 310hv. The microstructure of HAZ consists of bainite, ferrite, pearlite and a small amount of martensite. With the increase of fusion line distance, the hardness of the base metal decreases. The microstructure of the base metal is ferrite and pearlite, and the average hardness is 167hv.
Study on tribological properties of epoxy resin composites
Authors: Cao Jinling , Luo Ying
Published: May 2022

Epoxy resin has been widely used in many fields. The improvement of friction and wear property can further expand the application range of epoxy resin. Filling modification can improve the tribological state of epoxy resin and improve the friction and wear property of epoxy resin. This paper summarizes the research of epoxy resin composite material tribology performance at the forefront of progress. The influence of different fillers on the friction and wear properties of epoxy resin composite materials was discussed from the aspects of the single filling of nano-filler, organic materials and inorganic lubricating fillers and the compound filling of inorganic or organic-inorganic fiber-filler. Many researching literature shows. The mechanical properties of epoxy resin composites are strengthened by adding filler to epoxy resin to improve the load bearing capacity of epoxy resin composites during friction. At the same time, add filler to reduce the surface of epoxy resin and the friction pair of duality between the caking property, and in the process of friction is easy to form transfer film, transfer film to isolate the direct contact of the friction surface, composite materials and the dual friction between surfaces into composite materials and transfer film, the friction between improved tribological condition between the friction pair, reduce the friction coefficient and wear rate of epoxy resin composites multiple fillers can improve the wear resistance and reduce the friction coefficient of epoxy resin composites, so that the epoxy resin composites have better tribological properties.
Detection method for surface scratches of composite automotive components with high reflection and complicated background color
Authors: Peng Yanlong , Tian Dazhuang , Ma Binxuan , Tian Linli
Published: May 2022

Current testing status have the problems that the surface background color pattern of high reflective carbon fiber auto parts is complex, the shape of scratch defects is irregular, and the shallow and micro scratches are not easy to be detected. Aiming at the problems, a scratch detection method combining innovative morphological processing and optimized Canny edge detection algorithm is proposed. The image acquired by an innovative image acquisition platform. After gray processing and open operation denoising, the self-defined oval kernel secondary expansion is introduced in the morphological processing part. When threshold segmentation and minimum connected domain screening are done, the optimized Canny edge detection algorithm is used. Through the non-maximum suppression of gradient amplitude, a wide range of dual-threshold parameters are selected to detect the edge of the target image. The results show that the detection rate of the proposed method is 18.57% higher than that of the traditional way, and the detection rate is up to 95.71%. At the same time, the proposed method can reflect the scratch morphology more intuitively.
Effect of silica modified by silane coupling agent on properties of epoxy resin composites
Authors: Jie Qu , Li Yuanyuan , Lv Guanglei , Jiang Xiaobin , Yuan Shinin
Published: May 2022

Silica was modified by silane coupling agent, and then the modified silica was added to epoxy resin to prepare the composite. The modified silica / epoxy composites were characterized by scanning electron microscope, mechanical property test and contact angle test, and the effects of different silica dosage on the properties of the composites were studied. The results show that the mechanical properties of the composites can be greatly improved after the composite of modified silica and epoxy resin, and the optimum addition amount is 5%.
Comparison of cavitation erosion behavior of 45 steel and 0Cr18Ni9Ti stainless steel
Authors: Yao Zhihua , Zhang Chunyan , Li Shaoling
Published: May 2022

A cavitation erosion test of 0Cr18Ni9Ti stainless steel and 45 steel sample was performed in an ultrasonic vibration apparatus. The cavitation erosion behavior was studied by means of metallographic microscope, Vickers hardness test, scanning electron microscopy and mass loss analysis. The results showed that the surface hardness had an obvious influence on cavitation erosion, the higher the hardness, the better the cavitation erosion resistance was. Plastic deformation and fatigue fracture were the main mechanics of cavitation erosion of 0Cr18Ni9Ti stainless steel, whereas cavitation erosion of 45 steel was accompanied by oxidation, which will intensify cavitation erosion. Reasonable surface modification technology should be adopted for 0Cr18Ni9Ti stainless steel to improve surface hardness, and suitable surface protection technology must be used to resist cavitation erosion and oxidation for 45 steel under cavitation conditions.
Design of an environmentally friendly leather-like fabric based on thermoplastic polyurethane covered yarn
Authors: Wang Yang , Li Zhe , Cao Yang
Published: May 2022

By means of knitting and weaving, the new yarn was woven into a new eco-friendly leatherette. A series of research methods and data are summarized through the optimization and improvement of the design process and the heat-setting treatment of the fabric after weaving, which will bring a breakthrough in the reform of the preparation, research and development of new environmentally-friendly materials and product application. The new environmentally-friendly imitation leather fabrics is superior to similar products and boasts advantages in product application, such fabric is comfortable, breathable, waterproof, windproof, folding-resistant, wear-resisting and biodegradable. The cost of its production is much lower than expensive leather products, in the meantime, the space for design and development in the aspect of fabric texture, pattern, and color can be expanded more compared with other leather and imitation leather products.
Design and analysis of independent 3-link rear suspension for All-Terrain vehicle
Authors: Patel Pavan , Shah Vyom , Keshav Manjeet
Published: May 2022

The fundamental thought behind the paper is to configure, dissect just as recreate the Independent 3-Link suspension math introduced in the back of an Off-road Vehicle (ATV). An ATV as the name recommends is intended to handle a tremendous assortment of landscape than different vehicles. The Suspension framework which is the main imperative for taking care of has gone through a generous measure of advancement previously. Accordingly, the point is centred around planning the previously mentioned suspension framework joining elements of the vehicle with giving ideal execution of the vehicle while expanding driver comfort. Boundaries like camber, wheel travel, roll focus were assessed to achieve the wanted execution. As the ATV’s for the most part go through a colossal measure of shocks in harsh landscapes, the soundness of the vehicle was additionally given significance. by arms in CAD software.
Modeling and analysis of integrated wheel hub
Authors: Shah Vyom , Patel Pavan , Keshav Manjeet
Published: May 2022

The main objective of the hub is to act as a support structure to the entire wheel assembly of the vehicle. It is designed to absorb and dissipate the kinetic energy from the impact on the tire. This paper discusses an idea for optimizing the wheel assembly by redesigning, validating the design through analysis, material selection and overall weight reduction. The design optimization is done while taking in consideration of the design constraints, factor of safety (FOS) and manufacturability through conventional means. Weight reduction in the wheel assembly will help improve the suspension performance. The research is based on integrating parts of the wheel assembly for weight reduction, performance optimization and ease of assembly. The proposed design of wheel flange will be followed by material selection for attaining an adequate FOS and wear strength.
Guidance method of simulating weld trajectory between planes based on single-point laser
Authors: Chen Min , Ma Zhiling , Chen Li , Chen Junhong , Liu Yaohui
Published: May 2022

In the face of problems such as welding of small objects or too small welding space, an application method of welding small plane intersecting objects based on point laser was proposed. The demonstration points pointing to different planes were preset, and the laser displacement sensor was driven to measure the physical value by simulating the sharp workpiece of the welding gun. Multiple projections at different locations were made on a certain plane of the welding object, so as to ensure that the laser points were not collinear and obtain the laser point parameter set. The plane equation was solved respectively according to the planes pointed by different demonstration points, and a geometric model was built. The equation of the intersecting line between the planes in the welding object was calculated. The points on the line were obtained as the welding start points. The workpiece tip was controlled to move along the intersection direction by the mechanical arm, so as to achieve the weld effect.
Forklift with small turning radius and its efficiency
Authors: Amon Berdiev , Dong Zhang , Gayrat Bahadirov , Xuelin Wang , Qian Li
Published: May 2022

A forklift is one of the most widely used vehicles in industry sectors in few decades. Therefore, it is important to create or improve their entire designs. This article proposes a method for determining the required corridor width by calculating the turning radius of standard counterweight Forklift and the new construction of forklift and compares their parameters. The effect of the new type of fork on the efficiency of forklifts and warehouses was studied.
Study on the influence of restraint stiffness of main material on the compression stability bearing capacity of cross-bracing in transmission tower
Authors: Li Jiayao , Li Zhengliang , Huang Xing , Liu Hongjun , Wang Wenwu
Published: May 2022

In order to study the influence of restraint stiffness of main material on the compression stability bearing capacity of cross-bracing in transmission tower, in this paper, the load of cross-bracing under eccentric compression in transmission tower is simulated. The load test of 45 Q355 equilateral angle steel cross-bracing specimens with typical sections is completed, and an effective ANSYS finite element model is established for analysis. The effects of the restraint stiffness of main materials, slenderness ratio, material strength and the number of connecting bolts on the bearing capacity of cross-bracing are discussed, and the relevant laws are obtained, which provides a reference for engineering application.
Research and Application on Cooperative Positioning Technology in Substation Project based on BDS and UWB
Authors: Zhang Chengwei , Zhang Na , Chen Bingqian
Published: May 2022

This article mainly discovers and studies a cooperative positioning technology which combines Beidou Navigation Satellite System (BDS) and Ultra Wide Band (UWB) technology. BDS is mainly used for precise positioning in outdoor environments, and UWB technology can be widely used for positioning in both indoor and outdoor environments. This article firstly proposes a combined positioning technology based on BDS and UWB positioning technology, and proposes appropriate technical schemes and solutions for outdoor, indoor and indoor-outdoor transition areas. After considering the actual situation of the substation project, a coordinate conversion method that can be applied in the actual engeerning project is proposed to realize the unification of different coordinate systems and meet the needs of seamless positioning of indoor and outdoor panoramic views of the substation project. Finally, the field test results proves the effectiveness of proposed method.
Consistency-based Semi-supervised Learning Framework for Power Line Insulators Detection
Authors: Yao Xu , Lei Longwu , Zheng Zhou , Mo Wenhao , Wu Han , Li Shufang
Published: May 2022

It is commonly believed that fast and accurate object detection is the prerequisite for power line insulators automatic fault diagnosis. While the insulators detection task requires a huge number of labeled images to guarantee its performance, placing bounding boxes for every object in each image is time-consuming and requires professional knowledge. To alleviate this problem, we propose CASD, a two-stage semi-supervised learning framework for power line insulators detection based on consistency regularization and data augmentation. Firstly, we train a teacher model on labeled images, then generate pseudo labels for unlabeled images using the trained model, and the confidence-based thresholding is introduced to control the quality of pseudo labels. In the second stage, we apply strong data augmentation to unlabeled images and use both the labeled and unlabeled images to train the CASD. Consistency regularization is introduced in the calculation of unsupervised loss to improve the accuracy and robustness of the model. Finally, we compare CASD with supervised learning, data augmentation and self-training methods on insulators aerial image dataset. The results show that the proposed method performs better than all the three baseline methods, and the detection accuracy of CASD is far better than the supervised learning method in the case of less available images. The comparison results further prove the efficacy of the proposed method.
High Step-Up Resonant DC–DC Converter With Resonant Network for Electrical Collection Systems
Authors: Han Zhilu , Wang Guangzhu , Liu Yuhui , Guo Wenjie
Published: May 2022

The efficiency of renewable energy electrical collection can be effectively improved by adopting the high voltage direct current (HVDC) electrical collection method. The low-voltage DC power is stepped up to the high-voltage level for HVDC transmission by one-stage step-up type, which can reduce the cost of high-voltage large-capacity DC-DC converters. However, the high cost of DC-DC converters which can achieve high step-up ratio, such as modular multilevel converter (MMC), limits the development of the one-stage step-up type. In this paper, a low-cost DC-DC converter with high step-up ratio which can realize the bidirectional flow of energy is proposed. The total step-up ratio is the product of high-frequency transformer ratio, resonant network gain and step-up ratio of voltage doubler rectifier circuit. Meanwhile, the direct power factor control (DPFC) strategy is proposed based on the idea of controlling active power to achieve the goal of controlling output voltage. Finally, the step-up ratio of the DC-DC converter can reach 160 times, and realize zero-voltage switching (ZVS) turn-on of the switches and zero-current switching (ZCS) turn-off of the diodes.
Design and Simulation Analysis of Low-speed Tidal Current Energy Generator
Authors: Liu Wenzhou , Yang Minghao , Yao Xiaoyan , Xiao Xu , Jiang Zhihong , Zhang Xiao
Published: May 2022

As a kind of ocean energy, tidal energy is mainly caused by the flow of seawater accompanied by tidal phenomena. Tidal current power generation uses the rising and falling ocean currents to impinge on the impeller device of the turbine to rotate the impeller to generate electricity. Tidal current power generation has gradually attracted the attention of countries all over the world in recent decades because of its clean, strong regularity, and high energy density.This paper designs the magnetic circuit structure of a low-speed tidal current generator prototype with a rated power of 1KW, selects a suitable electromagnetic topology, initially determines the generator material and electromagnetic structure, and then uses finite element analysis software to conduct a two-dimensional simulation analysis of the generator. The results show that the current, voltage, and power of the prototype meet the design requirements, and the transient no-load and load analysis is completed. The parameters of the generator are verified to be within a reasonable range to ensure the stable operation of the generator.
Research on thermal management system of next-generation hybrid electric vehicle
Authors: Wang Jianpeng , Kong Fanming
Published: May 2022

New energy vehicles play a bigger role under the National VI emission standard and the double-point policy conditions, which is the focus of Original Equipment Manufacturers (OEMs) and consumers due to the advantages of low fuel consumption and long battery life. The front cabin of a hybrid electric vehicle (PHEV) includes the cooling system of the engine, electric motors, controller and condenser, etc. Compared with fuel and pure electric vehicles, the front cabin has a higher heat load, smaller space, and a great influence of the radiators for PHEV, which has more requirements for the cooling module. As people’s requirements for power and comfort continue to increase, the cost and energy consumption of thermal management systems are also rising. Hence, all OEMs have shifted their focus to developing a new generation of thermal management systems. The performance of the new-generation hybrid vehicle thermal management system can meet the performance requirements of the entire vehicle, and it has the advantages of being suitable for platformization, reducing costs, comprehensive utilization of vehicle energy to reduce energy consumption, high radiating efficiency, small front-end module size, and low fan power.
Open-circuit Fault Riding Through of Receiving AC Terminal in HVDC Transmission System for Offshore Wind Farms
Authors: Du Zhaoxin , Liu Shaojie , Wang Xingguo , Wang Shuyang , Zhao Huilong , Che Songyang , Tu Peng , Liu Han
Published: May 2022

Flexible high voltage direct current (HVDC) transmission system is indispensable for long-distance and high power transmission capacity in offshore wind farms. The AC open-circuit fault of the receiving terminal is quite severe, where the power transmission might be suddenly cut down to zero. As a result, a severe over-voltage will occur on the HVDC side and modular multilevel converter (MMC) submodule capacitor. In this paper, the over-voltage suppression mechanism is put forward to augment the AC open circuit fault at the sending and receiving terminal of the MMC-HVDC system. First, the formulation mechanism of DC over-voltage in the MMC-HVDC integrated wind farm is studied. Then, three different over-voltage suppression mechanisms, namely wind turbine pitch control, crowbar control, and submodule redundancy, are put forward to suppress the aforesaid over-voltage in the MMC-HVDC system. The simulations are carried out in PSCAD based on a test case, and the simulation results are used to confirm the efficiency of the proposed overvoltage suppression techniques.
Research on PMSM Sliding-mode Vector Combined Speed Controller Based on Improved Exponential Reaching Law
Authors: Wang Dongwen , Wang Dongheng , Zhou Wei , Niu Libo
Published: May 2022

Sliding mode control has good robustness, but the traditional sliding mode has the problem of chattering. Aiming at the conflict between velocity and chattering in the approach stage of sliding mode control, a new reaching law is put forward. By improving the isokinetic approach term of the traditional exponential reaching law, the system’s requirements in different stages of sliding mode motion are met, and this contradiction has been effectively improved. At the same time, to better improve the control effect of permanent magnet synchronous motor (PMSM) speed regulation system, combined with the traditional PI control with no static error and no overshoot, a combined speed controller combining sliding mode control and PI control is designed to enhance the robustness of the system. By building a model in Matlab/SIMULINK for simulation, the effectiveness of the improved exponential reaching law and the improvement of the system performance brought by the combined speed controller are verified respectively.
Study on Fault Optimization of Intermediate Joint of Power Cable
Authors: He Dajiang , Liu Bohan , Wang Zhenwu , Shu You , Liu Minghui
Published: May 2022

Cable joints are often prone to failure due to loose contact, small contact area and increased contact resistance, resulting in obvious heating. In the existing cable emergency repair work, the cable joints of the original section of the cable and the access end are made on site. Due to the long production time, the emergency repair speed is reduced. Therefore, this paper studies the connection mode of the new cable joint to make the contact between conductors more sufficient and the contact resistance smaller, and designs a scheme of three-phase cable plug-in intermediate joint with high safety and simple installation; at the position of cable joint, three kinds of flexible conductive polymer materials suitable for joint connection are proposed to be used at the contact gap between conductor and conductor, conductor and conductor sleeve, so as to make close contact, reduce contact resistance and further reduce the incidence of cable joint failure.
Study on Partial Discharge Fault Diagnosis of High Voltage Switchboard Based on Ultrasound Detection
Authors: Liu Meijie , Li Zhongwei , Qiu Peng
Published: May 2022

In view of the problem that the partial discharge type of switchgear still needs to be judged by the staff according to the collected phase diagram and experience after the erection of ultrasonic sensor, this paper establishes four common partial discharge models in switchgear, analyzes the collected ultrasonic signals in time domain and frequency domain, extracts 8 characteristic parameters, and judges the fault according to the characteristic parameters by support vector machine, The results show that the recognition rate is high, which lays a foundation for the application of ultrasonic testing in automatic partial discharge diagnosis and fault recognition.
Analysis of harmonic influence of improved PFC circuit on SS4G electric locomotive
Authors: Wang Xiangrong , Shi Guangtian
Published: May 2022

Compared with active filter, PFC circuit has simple structure and convenient operation. Introducing it into SS4G electric locomotive can greatly reduce system harmonics. Therefore, firstly, the corresponding PFC circuit is built, and the suppression measures of peak section and discontinuous section are proposed. By improving the discontinuous section, the waveform conduction angle is expanded from 129.564° to 162.882°. Accordingly, the current harmonic at the input side is reduced from 27.38% to 16.19%. After the voltage multiplier is further introduced, the harmonic is reduced to 15.77%. Then, the circuit is designed to absorb the high-order harmonic power in the peak section, and the harmonic is further reduced by about 0.33% to 15.44%. Two small order smoothing capacitors are connected in parallel in the load section to further absorb higher harmonics, which can reduce harmonics to 9.95%. Because the discontinuous section will also produce some spikes in the improvement process, improving the spikes can reduce the harmonics by 4.42% to 5.53%. Then the final improved circuit is introduced into SS4G circuit, and the current harmonic content of the circuit is reduced from 30.02% to 15.59%. The improved PFC circuit has achieved good results in SS4G.
Lithium battery SOH estimation through FFNN
Authors: Ye Zeyu , Liu Wanbo , Wang Xuechao , Zhu Jin , Yin Jingyuan
Published: May 2022

Abstract:The battery health plays a key and decisive role in the use of lithium batteries. In this paper, the battery data detected offline is used to predict SOH through the big data platform algorithm model, in order to acknowledge the current health of the battery. The construction of the learning model is carried out through the historical data of 1000 batteries data set, so that the MAE(mean absolute error) is lower than 0.095%.
Study on the Influence of Energy Storage on the VRE Station’s Utilization Rate
Authors: Chen Ning , Wang Caixia , Yu Qiuxia , Fan Hao , Li Qionghui , Yuan Wei
Published: May 2022

With the proposal of carbon peak and neutrality goals, variable renewable energies (VREs mainly wind power and solar) will usher in fast development. To ensure the effective consumption of VREs, it is necessary to improve the flexibility of power system. With the high proportion of VREs, the risk of insufficient flexibility of power system increases, and serious abandonment of VREs may occur. Energy storage is an effective means to improve system flexibility and increase VREs’ utilization rate. At present, many provinces in China have issued requirements for the allocation of energy storage for VRE projects, but there is little literature to analyze the impact of the allocation of energy storage in VRE stations on the utilization rate of VREs. In this paper, the joint optimization model of VRE stations and energy storage is established, which can accurately simulate the equivalent power after energy storage is configured in the VRE station. This model is used to study the impact of energy storage configuration proportion on the utilization rate of the VRE station.
Energy management optimization of integrated energy system with electric hydrogen hybrid energy storage
Authors: Huang Jian , Hou Jiansheng , Wang Yingcong , Zheng Hang , Jin Jianfeng , Meng Qinghao
Published: May 2022

Integrated energy system (IES) has attracted wide attention as an efficient solution to a comprehensive utilization of hybrid energy system including electricity, heat, and hydrogen in recent years. This paper investigates the stochastic optimal operation for the micro integrated electric power, heat, and hydrogen delivery system. Firstly, the mathematical model of the micro integrated energy system for residential communities and other similar scenarios is discussed, including the energy interface, power microgrid, micro-heat system and micro-hydrogen system with considerations of distributed energy supply, energy storage, load, upstream energy network interface and their mathematical models. Secondly, the correlated uncertainty, such as wind power, solar power, and loads, are considered and handled in micro integrated energy system. Finally, a scenario-based approach is proposed for the stochastic operation of micro integrated energy system. The objective function is formulated to minimize the expected total operation and environmental costs, the hourly schedule of controllable components in micro integrated energy system. Numerical results demonstrated that the effectiveness of the proposed method. The correlated uncertainty and the corresponding impacts are accurately presented in the optimization model.
Research and application of cluster distributed generation virtual power plant regulation mode based on multi-source heterogeneous data flow analysis
Authors: Li Bin
Published: May 2022

In view of the increasing demand for multi-source heterogeneous data interaction in cluster distributed power virtual power plant(VPP), this paper analyzes the data sources and data flows in each interactive system, and studies the interface strategy between these heterogeneous data and VPP; On this basis, a multi-source heterogeneous data integration platform is built. Based on the data platform, a two-level coordination mode of intelligent regulation of VPP is proposed and realized; Finally, a practical demonstration project is carried out to verify the feasibility of the relevant schemes.
Multi-object optimal configuration of energy storage-photovoltaic capacity in AC/DC active distribution network
Authors: Wang Chen , Yang Fu , Chen Xiuqiang , Song Houming , Li Zhihua
Published: May 2022

The AC/DC active distribution network is considered as an efficient way to achieve intelligent use of electricity. However, the economical configuration of distributed generation is critical for system economic operation. In the power distribution network, the economic operation mode of the photovoltaic power generation, storage battery and load are established firstly. Considering the cost of equipment installation, replacement, operation and maintenance, power purchase cost, and power sales profit, the use life of battery and security constraint, a multi-object economics evaluation function is then established. By optimizing the install capacity of distributed power generation, the operating economy of the distribution network is significantly improved. Finally, using the operating data of the partner-type intelligent power generation system in Lianyungang, the total cost of the operating state is calculated to determine the optimal capacity allocation scheme of the system, and the effectiveness of the proposed capacity allocation method is verified.
Research on running control strategy of photo-hydrogen coupling energy block system based on homogenization modeling
Authors: Han Zijiao , Wang Liang , Dong Yannan , Ge Yanfeng , Ge Yangyang , Ning Chen , Liu Zirui
Published: May 2022

With the in-depth development of economy, the problem of energy transformation is imminent. Both solar energy and hydrogen energy play an important role in low-carbon energy, which can effectively reduce the dependence of the existing energy system on traditional fossil energy and reduce environmental pollution. In order to improve the consumption rate of photovoltaic power generation and the utilization rate of hydrogen energy, this paper analyzes the power exchange characteristics of heterogeneous energy, establishes the homogenization model of various heterogeneous energy, and puts forward an effective running control strategy. While making the output power of photovoltaic generator set meet the power demand of load, hydrogen energy can be maximally applied. Finally, a simulation example is given to verify the effectiveness of the running control strategy proposed in this paper.
Machine vision based insulator image chip drop fault recognition method
Authors: Tang Jie , Huang Zhidu , Zhu Dengjie , Li Hao , Zhao Linjie
Published: May 2022

The paper studies the method of insulator image chip drop fault recognition based on machine vision to improve the recognition effect of insulator chip drop fault.Zhang’s calibration method was used to calibrate the internal parameters of binocular vision camera to improve the results in image acquisition. Insulator images were captured by binocular vision camera after calibration. The color image is converted to digital image and the insulator target image is extracted from the saturation component of a digital image by the optimal entropy threshold segmentation method. The nonlinear function is used to correct the high-frequency subband coefficients in different scales and different directions in the insulator target image, and the coefficients are used to extract the high-frequency information of different scales and directions.. The improved one-dimensional Hough transform detection algorithm is used to identify the ellipse in the edge image, that is, the insulator. The decision conditions of fault identification are designed to complete the fault identification of insulator drop. Experiments show that this method can clearly collect insulator images under different weather conditions, effectively segment insulator target images and accurately extract insulator edge information. The method can accurately identify the insulator drop fault based on the ellipse detection results. When the contrast and brightness factors are different, the f1-score value of fault recognition is higher and the fault recognition effect is better.
Research on Design Method of Intelligent Operation and Maintenance System for Secondary Equipment in Intelligent Substation
Authors: Kuang Honggang , Hu Zongjun , Li Xiaobin , Feng Chao , Gong Can , Yan Jian , Shu Chang
Published: May 2022

Smart substations are an important part of establishing a strong smart grid. In view of the large variety of secondary equipment in the current power system, the rapid increase in quantity, and the complex working conditions of the current power supply company maintenance classes to inspect substations, a design method for the intelligent operation and maintenance system of secondary equipment in smart substations is proposed in this article. First, the intelligent operation and maintenance system architecture of the secondary equipment of the smart substation is established via Redis and ActiveMQ technologies. Then the system function module model is established. Finally, taking a 220kV substation in a certain area of southern China as an example, a new type of intelligent substation secondary equipment intelligent operation and maintenance system was installed and connected to the main line system, and the effectiveness of the proposed method was verified.
Research on Optimum Ratio of New Energy Installed in Shandong Power Grid
Authors: Liu Dong , Sun Yi , Wang Xian , Shi Bingke , Liu Rui , Wang Yao
Published: May 2022

In recent years, we have witnessed the rapid growth of new energy sources in China, with the implementation of “carbon peak, carbon neutrality” and new power system, there is no doubt that the development of new energy will maintain a rapid growth rate. At the same time, in order to ensure the high-quality development of new energy, the planning of wind power and photovoltaic should be taken in advance. Taking Shandong Power Grid as an example, this paper analysed the optimal installed ratio of wind power and photovoltaic power in Shandong power grid from the perspective of electrical power balance, aiming at the highest fit between wind and photovoltaic power generation and load curve. The calculation results show that when the installed ratio of wind power and photovoltaic is 1.45:0.8 (about 1.8:1), the wind and photovoltaic power generation can fit the load curve most closely. Based on this, some suggestions are put forward to provide technical support for energy and electric power planning.