关键词：
Discharges (electric);Costs;Batteries;Planning;HVAC;US Department of Defense;Home appliances;Battery energy storage system (BESS) capacity determination;cloud energy storage (CES);demand-side management;home energy management;second-life BESS (SL-BESS)
摘要：
Second-life battery energy storage systems (SL-BESSs) have potential to be used as an economic and affordable energy storage solution for supporting a variety of applications, such as energy backup in residential sector. This article proposes a new capacity determination framework for SL-BESSs that are utilized in household environment. Despite the capital cost is significantly reduced, the degradation characteristics of retired batteries exhibits two-stage decline characteristics. The proposed framework first establishes the SL-BESSs model and estimates its remaining useful lifetime by identifying the "knee point " in the SL-BESSs capacity degradation curve; based on this, a two-level SL-BESS capacity determination model is formulated, which sizes the SL-BESS based on short-term home energy management under different scenarios. In particular, this article considers the dual-service modes of an SL-BESS in its capacity determination process: first, provide local energy supply to the household, and second, provide cloud energy storage service to external users. Extensive numerical simulations are conducted to validate the proposed framework.
关键词：
Convolutional neural network;dynamic convolution;dynamic large kernel;dynamic small kernel;pansharpening
摘要：
Pansharpening is a spatial-spectral fusion technique that fuses low-resolution multispectral (MS) images with high-resolution panchromatic (PAN) images to get high-resolution MS images which are rich in spectral and spatial information. Some pansharpening methods based on dynamic convolution were proposed to improve the adaptivity and generalization of the fusion network. However, these methods either only focus on local small regions or generate dynamic filters with a complex network. Besides, the dynamic filters in the existing methods only convolve with MS or PAN images, resulting in the extracted details or spectral features are inadequate. In this letter, we propose a dynamic large-small kernel convolutional network. To obtain small scale features, we propose a dual dynamic small kernel (DDSK) module which consists of dynamic spatial small filter (DASF) and dynamic spectral small filter (DESF). The multiscale dynamic large kernel convolution (MDLC) module is designed to expand the receptive field for obtaining large scale features. Considering the differences between PAN and MS images, DASF and spatial MDLC modules are presented to extract the details of PAN image. Similarly, DESF and spectral MDLC modules are proposed to obtain the spectral features of MS images. The proposed method is evaluated on GaoFen-2 and WorldView-3 datasets, and our method shows good performance.
通讯机构：
[Deng, F ] ;Changsha Univ Sci & Technol, Coll Elect & Informat Engn, Changsha 410076, Peoples R China.
关键词：
Fault location;single end;traveling wave full waveform;convolution neural network;feature extraction
摘要：
Conventional single-ended traveling wave fault location methods, which commonly depend on partial features of traveling wavefronts, may lead to fault location failure, especially for weak-signal faults such as high impedance or zero-crossing faults and close-in faults. To tackle it, this article presents a fault location method according to the extracted panoramic features of traveling wave full waveform (TWFW) in time-frequency domains. Firstly, two rules of the TWFW features are probed, that is, the wavefront arrival sequence is varied from fault sections, as well as the frequency distribution of wavefronts is strongly related to the precise fault distance. Ergo, the mapping relationships between the TWFW and fault distance are qualitatively confirmed in order to demonstrate the uniqueness of the TWFW subsequently. Next, a LeNet-5-based convolution neural network (CNN) model is constructed to quantitatively evaluate such mapping relationships. In this model, various TWFW features will be extracted to the convolution channels when the CNN parameters are optimized adaptively, and the mapping relations can be formed in light of these sensitive features to estimate the fault distance. Finally, a Grad-CAM visualization method is deployed in the case study, and the accuracy along with the robustness of the proposed method in various fault conditions can be validated consequently.
摘要：
This paper proposes a decoupling control method to eliminate frequency coupling in three-phase grid-tied system. Firstly, the admittance model of three-phase <italic>LCL</italic>-type three-phase grid-tied converter (GTC) considering DC-bus voltage control (DVC) loop and phase-locked loop (PLL) is established in <italic>dq</italic>-domain frame, and the influence of asymmetrical DVC and PLL control structure on frequency coupling oscillation is analyzed. Then decoupling factors are added to the DVC loop and current control (CC) loop to achieve that the off-diagonal elements of the sequence admittance matrix of the GTC are 0, which means the frequency coupling in the GTC is eliminated. Therefore, the GTC system can be regarded as a single input single output (SISO) system, and the stability can be analyzed by the classic Nyquist criterion in the sequence-domain frame. Compared with the double input double output (DIDO) system, the resulted SISO system convenient for calculating the stability margin of the system and guiding parameter design. In addition, the SISO system is easier to be analyzed on the oscillation and resonance mechanism, and the analysis results can be used to optimize the design of the converter controller, grid planning and operation. Finally, simulation and experiment verify the feasibility and effectiveness of the proposed decoupling control method. IEEE
摘要：
Fault prediction of electromechanical equipment can greatly reduce its maintenance cost and prevent catastrophic damage. In order to realize the accurate fault prediction of electromechanical equipment, a fault prediction method based on spatial-temporal graph information is proposed in this article. In the proposed method, the signal data of each intermittent monitoring period are expressed by Markov field graph information, and the spatial-temporal correlation features of graph information are extracted and studied by multivariate spatial-temporal graph neural networks. The effectiveness of Markov graph information for different state expressions is demonstrated by motor fault data from the motor fault experimental platform, and the bearing fault prognostics data is used to demonstrate the feasibility and accuracy of the proposed fault prediction method. The results show that based on the local spatial state information and global time correlation information of monitoring signals, this method could accomplish accurate long-term and short-term fault prediction tasks, respectively.
关键词：
electric vehicle;path planning;particle swarm algorithm;genetic algorithm;optimization
摘要：
In this paper, with the current practical application in logistics industry as the background, from electric vehicle charging scheduling and path planning, a hybrid algorithm combining genetic-particle swarm algorithm is proposed to plan the best driving route for a group of electric logistics vehicles with vehicle load, vehicle battery life, charging fa-cility location and customer time window as constraints and the total cost as the objective function. Based on the single distribution center, a more complex multi-distribution cen-ter electric vehicle path planning problem is considered. In this paper, multiple sets of Solomon VRPTW data sets are selected to test the prepared algorithm, and the results show that the algorithm can effectively plan the best distribution scheme.
摘要：
Accurate fault detection and classification help to analyze fault causes and quickly restore faulty phases. Deep learning can automatically extract fault features and identify fault types from the original threephase voltage and current signals. However, this still imposes challenges such as recognition accuracy and computational complexity. More importantly, high level fault features cannot be extracted in the one-dimensional time series. This paper presents a robust fault classification method based on SA-MobileNetV3 for transmission systems. Considering that the SE (Squeeze-and-Excitation) attention module cannot aggregate the spatial dimension information on the channel, SA (shuffle attention) module is introduced into MobileNetV3, which can effectively fuse the importance of pixels in different channels and in different locations at the same channel. Also, transforming the time series threephase voltage and current signals into two-dimensional images based on CWT (continuous wavelet transform) makes the proposed method be similar to image recognition, which can mine high level fault features and classify the faults visually. To verify the effectiveness of the method, a 735kV transmission line model is built for data generation through Simulink. Various kinds of fault conditions and factors are considered to verify the adaptability and generalizability. Simulation results show that the method can quickly and accurately identify 11 types of faults, and the accuracy rate is as high as 99.90%. A comparison between the proposed method and other existing techniques shows the superiority of the proposed SA- MobileNetV3, and better anti-noise performance makes it more suitable for real fault signals taken on-site. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
关键词：
wildfire near transmission line;helicopter;flame retardant
摘要：
Dropping fire retardants by helicopter can effectively reduce the intensity of wildfires. This study proposes a test plan for spraying different fire retardants from a helicopter bucket fire extinguisher. In this study, pure water, 10% Class AB flame retardant, 0.3% gel flame retardant, 10% Class A flame retardant, and 10% Class A flame retardant + 0.6% guar gum were each added to the bucket fire extinguishing device and sprayed on 4-layer, 6-layer, and 12-layer wood cribs. The radiation intensity, mass loss, and temperature were used as indicators to compare the burning intensity of the fire field and the difference in fire field combustion intensity after the wood cribs were ignited 1 h after natural air drying. The results showed that flame retardancy could be ranked from high to low as follows: 10% Class A flame retardant + 0.6% guar gum > gel flame retardant > 10% Class A flame retardant > Class AB flame retardant > pure water. During the long-term high temperature and drought period in Hunan Province, China, from August to September 2022, a field application showed that dropping fire retardants by helicopter effectively reduced the intensity of wildfires and avoided transmission line trips due to the wildfire, which reduced the number of ground personnel required when fighting large-scale forest fires.
摘要：
This paper presents an anti-swing control method to prevent situations where inspection robots detach and fall off transmission lines during obstacle crossing due to excessive swing angles caused by the rotation of the robot around the transmission line. Firstly, an obstacle-crossing model for the inspection robot was constructed and the causes of robot swinging phenomena were analyzed, in addition to their impact on obstacle crossing stability. By combining this with the obstacle-crossing model, a moment balance equation was established for the inspection robot. This equation can be used to solve mapping relationships between body offset and the tilt angle of transmission line gripping arms. We propose an anti-swing control strategy by adjusting the angle of the transmission line gripping arm’s pitching joint to make the body offset approach zero, and by utilizing the advantages of fuzzy logic in the fuzzy PID algorithm compared with the traditional PID algorithm, it can adaptively avoid the occurrence of robot swinging phenomena. The experimental results of obstacle-crossing experiments under no wind and wind turbulence conditions indicated that the proposed anti-swing control method in this study can effectively keep the body offset to within 3 mm. Compared with the methods of not using anti-swing control and using traditional PID anti-swing control, in the absence of wind effects, the peak values of body offset were reduced by 96.53% and 18.85%, respectively. Under the influence of wind turbulence, the peak values of body offset were reduced by 97.02% and 27.12%, respectively. The effectiveness of the anti-swing control method proposed in this paper has thus been verified.
期刊：
IEEE TRANSACTIONS ON NETWORK SCIENCE AND ENGINEERING,2023年:1-12 ISSN：2327-4697
作者机构：
[Bangzhe Yin] Shaoyang Power Supply Company, State Grid Hunan Electric Power Company Limited, Shaoyang, China;UNEP DTU Partnership, Technical University of Denmark, Copenhagen, Denmark;Energy Resources, Development and Environment (ERDE) Lab, University of British Columbia, Vancouver, BC NSW, Canada;[Hongming Yang; Dingzhong Xu; Sheng Xiang; MingYong Lai] International Joint Laboratory of Ministry of Education for Operation and Planning of Energy Internet based on Distributed Photovoltaic-Storage Energy, Hunan Provincial Engineering Research Center for Electric Transportation and Smart Distribution Network, School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha, China;[Archie James Johnston] University of Sydney, Sydney, Australia
摘要：
To improve the power supply ability, heat supply ability, and waste recovery rate, a recycling electricity/heat rural supply system with waste feedstock is established. The energy supply system generates electricity/heat from biomass energy produced by wastes, which is also coupled to distributed renewable energy. The optimal scheduling of the established rural system will improve energy efficiency and cause emission reduction. Firstly, the waste recovery process is presented, and the architecture of the energy supply system is designed for the 100% absorption of renewable energy in rural areas. A carbon accounting model based on the locational marginal carbon emission factor is introduced, which considers the power exchange with the bulk power system and the carbon emission of biomass. Secondly, the optimal scheduling model for the recycling energy supply system is proposed to minimize both the total cost of energy supply and carbon emission, based on the constraints of energy balancing of electricity and heat, net carbon emissions, waste supply, etc. Finally, the IEEE 15-node system and PG&E 69-node system are employed for verification purposes. The proposed model contributes to 100% absorption of renewable energy and the efficient utilization of waste through the optimal cooperation of the waste supply, biomass power generation, and biomass heat, thereby supporting the achievement of zero carbon. IEEE
