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International Wireless Communications and Mobile Computing Conference, IWCMC

作者： Jiahao Shen Tao Zhang Bingchi Zhang Weixiao Ji Xiaohui Kuang Changqiao Xu State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China State key Laboratory of Science and Technology on Information System Security Beijing China

The growing multimedia services have brought unprecedented challenges to the traditional static network architecture. Moving Target Defense (MTD) has been proposed to solve the inherent disadvantages of existing defense techniques. As an important area of MTD research, Route Mutation (RM) can dynamically change the forwarding routes in the network. In our previous work, we applied Reinforcement Learning (RL) to RM. However, there are still two problems that need to be addressed. 1) We consider too few constraints to reflect the actual network situation. 2) Due to the slow rate of convergence, it becomes difficult for efficient deployment. In this paper, we propose a Proximal Policy Optimization Based Route Mutation (PPO-RM) scheme to solve these problems. Firstly, we utilize the Satisfiability Module Theory (SMT) to formalize the space of all possible mutated routes. Then, we design an RM algorithm based on Proximal Policy Optimization (PPO) and implement it in the SDN controller. Finally, we simulate on Mininet to validate our method. The experiment results show that PPO-RM achieves the improvement in terms of convergence rate, defense performance, and network performance.

关键词： Wireless communication Computational modeling Reinforcement learning Multimedia computing Aerospace electronics Network architecture Multimedia communication

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Research on Transforming Effect and Calculation Method of MMC Converter on AC / DC Harmonics

Research on Transforming Effect and Calculation Method of MM...

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2021 IEEE Sustainable Power and Energy Conference, iSPEC 2021

作者： Cui, Liu Peng, Guangqiang He, Jingsong Wu, Jiyang Mao, Chizu Jiao, Ning Electric Power Research Institute China Southern Power Grid State Key Laboratory of Hvdc GuangZhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System GuangZhou China Csg Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid GuangZhou China Maintenance Test Center Ehv Power Transmission Company Guangzhou China Csg Key Laboratory for Dc Transmission Equipment State Evaluation and Fault Diagnosis GuangZhou China Sichuan University College of Electrical Engineering and Information Technology Chengdu China

ISBN: (纸本)9781665414395

Modular multilevel converter (MMC) is currently the most concerned voltage source converter topology in the field of flexible direct current transmission (VSC-HVDC). Due to its non-linear characteristics, harmonic components will inevitably be generated in AC and DC systems, which may affect the operation of equipment and system, cause protection equipment to malfunction, and cause interference to neighboring communications. The MMC converter is a non-linear device, which can be considered as an amplifying modulator with voltage and current conversion functions. The AC and DC networks are coupled to each other through the MMC converter to generate dynamic harmonic interaction. In recent years, harmonic instability problems have appeared in many VSC-HVDC projects. Compared with other converter topologies, the transfer relationship of harmonics on the AC and DC sides of MMC converters has not been studied in depth. In this paper, by studying the AC/DC harmonic conversion characteristics of MMC converters, it reveals the conversion law of MMC converters between AC/DC harmonics;through theoretical derivation, the quantitative calculation method of MMC harmonic transmission process is given. PSCAD simulation results prove the correctness of the above results. © 2021 IEEE.

关键词： Transmissions

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Generalized Study on Analysis and Suppression Strategy of Circulating Current for Modular Multilevel Cascaded Converters

Generalized Study on Analysis and Suppression Strategy of Ci...

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Smart Power & Internet Energy systems (SPIES), International Conference on

作者： Mengchao He Yunfei Xu Zhengang Lu Guoliang Zhao Minxiao Han State Key Laboratory of Alternate Electrical Power System With Renewable Energy Source North China Electric Power University Beijing China State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co. Ltd Beijing China State Key Laboratory of Electrical Equipment and Electrical Insulation Xi'an Jiaotong University Xi'an China

Modular multilevel cascaded converter (MMCC) is widely used in medium and high voltage energy conversion in power systems. Circulating current and branch power fluctuation are common problems in MMCC, and due to different topologies, submodule types and input/output properties, their characteristics vary greatly. In this paper, a general characteristic analysis method of circulating current based on MMCCs’ network topologies is proposed. On this basis, a general suppression strategy for circulating current is proposed, which is easy to implement and can be combined with a branch energy balance strategy. The correctness of the proposed theoretical analysis and control algorithm, which provides an important theoretical basis for the development and application of MMCC is verified by the PSCAD/EMTDC simulation platform.

关键词： Fluctuations Network topology Genetic expression High-voltage techniques Energy conversion Control systems Topology

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A Method Based on Deep Reinforcement Learning to Generate Control Strategy for Aircrafts in Terminal Sector 2nd

A Method Based on Deep Reinforcement Learning to Generate Co...

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2nd International Conference on Artificial Intelligence in China, ChinaAI 2020

作者： Xu, Qiucheng Huang, Jinglei Liu, Zeyuan Ding, Hui College of Civil Aviation Nanjing University of Aeronautics and Astronautics Nanjing211106 China State Key Laboratory of Air Traffic Management System and Technology The 28th Research Institute of China Electronics Technology Group Corporation Nanjing210007 China

ISBN: (纸本)9789811585982

With the increasing air traffic density and complexity in terminal sector, air traffic controllers will face more challenges and pressures to ensure the safe and efficient operation of air traffic. In this work, an artificial intelligence (AI) agent based on deep reinforcement learning is built to mimic air traffic controllers, such that the dense, complex and dynamic air traffic flows in terminal airspace can be handled sequentially and separated. To simplify the problem, the complex three-dimensional terminal sector is projected onto the vertical plane by dispersing state space and action space. And then, the typical reinforcement learning algorithm, double deep Q-network, is taken to realize the AI agent. Results show that the built AI agent can guide 6 aircrafts safely and efficiently through Sector 01 of Nanjing Terminal, simultaneously. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Reinforcement learning

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Short Circuit Detection Method for GaN MIS-HEMT Power Devices Based on Gate Leakage Charge

Short Circuit Detection Method for GaN MIS-HEMT Power Device...

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Power Electronics and Application Symposium (PEAS), IEEE International

作者： Yingpeng Hu Pengju Sun Yufeng Lan Zou Can JianChao Zhou Zidong Li State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing University Chongqing China STATE GRID Super High Voltage Branch of Chongqing Electric Power Company Chongqing China Equipment Department of Chongqing STATE GRID Electric Power Company Chongqing China

To ensure the reliability and safety of GaN High Electron Mobility Transistor (GaN HEMT) power devices operating at high temperature, high frequency and high voltage, it is important to study the short circuit protection methods of GaN HEMT power devices. This paper proposes a short-circuit detection method based on gate leakage charge for GaN Metal-Insulator-Semiconductor HEMT (GaN MIS-HEMT). During a short circuit fault, a rapid spike in junction temperature can cause a gate leakage current in the gate loop. The proposed method is immune to parasitic parameters caused by the package and PCB layout, and can realize short-circuit detection within $\mathbf{1}\boldsymbol{\mu}\mathbf{s}$ . With the increase of the short-circuit bus voltage and ambient temperature, the short-circuit detection time can be shorter, which is more suitable for high-temperature, medium and high voltage applications.

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A novel soft exosuit based on biomechanical analysis for assisting lower extremity 22

A novel soft exosuit based on biomechanical analysis for ass...

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22nd IEEE International Conference on E-Health Networking, Application and Services, HEALTHCOM 2020

作者： Liu, Youfu Chen, Chunjie Lu, Jun Liu, Yida Zhang, Yu Wang, Zhuo College of Mechanical and Electrical Engineering Shaanxi University of Science and Technology Shenzhen China ShenZhen College of Advanced Technology University of Chinese Academy of Sciences Shenzhen China Guangdong Provincial Key Lab of Robotics and Intelligent System Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen China CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institutes of Advanced Technology Shenzhen China Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen China

ISBN: (纸本)9781728162676

In the past two decades, with growing focus of lower limb exoskeleton, large variety of rigid exoskeletons were designed for medical rehabilitation and the other purposes. Compared with the rigid exoskeletons, which added extra inertial to low limb and restricted wearers' movement, the soft wearable lower extremity exoskeleton minimized the impact of these factors on the human body locomotion. In this paper, a novel design of exosuit that provided assistive force for both hip extension and flexion through the variation in hip joint dynamics during strides was proposed. Based on the change of hip moment, an assistance strategy and assistance force curve were came up with. PD type iterative learning control (ILC) method was introduced to reduce the error caused by wearing position and biological characteristics to improve assistance performance. To evaluate assistance performance, the metabolic cost of four subjects wearing exosuit and walking on treadmill at 5km/h in the situations of that without assistance, assisting both hip extension and hip flexion, and assisting hip extension respectively was measured. Compared with assisting hip extension only and wearing exosuit with no assistance, results indicated that the decrease in average net metabolic cost of assisting both hip extension and flexion was 0.445W/kg and 1.027W/kg respectively, corresponding to the average net metabolic cost rate decrease was 7.45% and 15.67%. © 2021 IEEE.

关键词： Exoskeleton (robotics)

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One-Step Process of Wrinkle Microstructured Iontronic Pressure Sensor with All Fabric Wearable Electrode

SSRN

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SSRN 2024年

作者： Zheng, Kai Yang, Xuan Dai, Dongfang Li, Jincheng Shu, Ku Luo, Mei-Dan Chen, Xianping Yu, Jiabing Huang, Yexiong College of Optoelectronic Engineering Key Laboratory of Optoelectronic Technology & Systems Education Ministry of China Chongqing University Chongqing400044 China School of Electrical Engineering State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing400044 China Department of Energy Conversion and Storage Technical University of Denmark Kongens Lyngby2800 Denmark School of Physics and Electronic Engineering Chongqing Normal University Chongqing401331 China

The advancement of pressure sensors featuring high sensitivity, wide detection ranges, and linear response characteristics is important for advancing tactile sensing technologies for robots and human health monitoring. However, preparation using conventional methods suffers from nonlinear signal output, non-environmental friendliness, and poor comfort, which affects the sensor's ability to accurately detect different pressure levels, which is critical for subtle haptic feedback systems. To overcome these challenges, our research introduces a breakthrough in flexible capacitive pressure sensors by ingeniously integrating thermal stress-induced microstructured ionic gels with textile electrodes within a band-aid-like form factor. This method obviates the requirement for external templates or intricate manufacturing procedures, streamlining the production process while enhancing the sensor's performance. The pivotal role of the ionic gel lies in its ability to form an efficient electric double layer (EDL), which adeptly transforms ion-electron interface interactions into measurable pressure-sensing outputs. Notably, this band-aid-based iontronic sensor showcases exceptional performance metrics. It exhibits an extraordinarily high areal sensitivity, reaching 5652.41 kPa−1, and demonstrates a broad pressure detection range. Additionally, the sensor responds rapidly to pressure changes, maintains robust long-term cycle stability, and boasts an impressively low detection threshold. Its potential applications, particularly in the precise monitoring of human muscle movements, open exciting new avenues for both health monitoring and the broader field of flexible electronic devices, and illuminates the potential for everyday materials in advanced technological applications. © 2024, The Authors. All rights reserved.

关键词： Pressure sensors

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Material state Identification of the Conveyor Belt based on Inception-v4

Material State Identification of the Conveyor Belt based on ...

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2021 China Automation Congress, CAC 2021

作者： Tang, Jinliang Cai, Zhenyu Xu, Chao Chen, Tehuan School of Mechanical Engineering and Mechanics Ningbo University Ningbo China System Integration Center Huzhou Institute of Zhejiang University Huzhou China State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou China

ISBN: (纸本)9781665426473

For the uneven phenomenon of materials during material transportation on the factory assembly line, this paper proposes an improved model based on Inception-v4 to realize the identification and classification of three material states (more materials, normal materials, and fewer materials). In the image processing stage, the Farneback algorithm is used to capture the moving area, which makes the training of the model focus on effective information. In addition, considering the color bias of materials, the RGB enhancement strategy is proposed. By processing the image data in RGB channels, different weights are given to realize the enhancement of image features. In the network training and testing stage, we use Inception-v4 as the baseline model. The output of the model is modified for the classification task, and a new loss function is designed. In addition, considering the limited sample size, we pre-trained the model on ImageNet. Through experimental comparison, the improved algorithm proposed in this paper has better performance. © 2021 IEEE

关键词： Optical flows

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Dynamic Phasor Estimation Method Considering False Data Injection Attack 5

Dynamic Phasor Estimation Method Considering False Data Inje...

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5th IEEE Conference on Energy Internet and Energy system Integration, EI2 2021

作者： Zhao, Qingsheng Liu, Yifeng Zhao, Dakai Liang, Dingkang Guo, Zun Shanxi Key Laboratory of Power System Operation and Control College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan China State Grid Economic and Technological Research Institute Co. Ltd Beijing China

ISBN: (纸本)9781665434256

When the smart grid data acquisition system is attacked by false data injection, because the measured data is tampered, the wrong state estimation will lead to the wrong action of the smart grid controller. This paper proposes a dynamic phasor estimation method considering false data injection attack. Firstly, the electrical signal model suitable for dynamic conditions is established by Taylor series expansion of the electrical signals which include harmonic, noise and other conditions;Then, the method which based on the double suboptimal-scaling factor strong tracking Kalman filter algorithm (DSTKF) and Euclidean distance is used to detect, track and estimate the phasor;Finally, the proposed estimation method is used to simulate the electrical signal with noise and false data attack. Besides, the signal of IEEE 39-bus system is also estimated with this method. The results show that this proposed method can not only detect the false data attack and mutation in electrical signal, but also has high estimation accuracy and tracking ability for dynamic phasor. © 2021 IEEE

关键词： Kalman filters

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Icing Flashover Tests and Arc Developing Characteristics on Superhydrophobic Surface 7

Icing Flashover Tests and Arc Developing Characteristics on ...

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7th IEEE International Conference on High Voltage Engineering and Application, ICHVE 2020

作者： Liu, Jie Hu, Jianlin Tan, Huilin Ding, Zhiyuan Jiang, Lihua Meng, Wei State Key Laboratory of Power Transmission Equipment System Security and New Technology Chongqing University Chongqing China

ISBN: (纸本)9781728155111

The faults caused by transmission line icing seriously influence normal operation of power system. The application of superhydrophobic material on the anti-icing of transmission and distribution electricity equipment has caused widely concern in recent years. This paper takes icing flashover tests in a multifunctional artificial chamber on glass plates with superhydrophobic coatings and uncoated control group, respectively. The different characteristics between superhydrophobic surface and hydrophilic in ice morphology, and the flashover voltage changed with icing time are obtained in the experiments. According to analysis of the development of arc on ice surface, this paper builds a flashover equivalent model of ice covered superhydrophobic surface. © 2020 IEEE.

关键词： Flashover

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