Search

Your search keyword '"Liu, Zhixiang"' showing total 67 results
Start Over Author "Liu, Zhixiang" Publisher ieee
67 results on '"Liu, Zhixiang"'

18. Reliability Analysis of Protective Relaying for 3rd Generation Smart Substation

Author

Liu Zhixiang, Yang Shihao, Lu Zhihao, and Han Songjie

Subjects
Fault tree analysis, Engineering, business.industry, Ground, Smart substation, Monte Carlo method, Protective relay, ComputingMilieux_LEGALASPECTSOFCOMPUTING, Protection system, business, Reliability (statistics), Working environment, Reliability engineering
Abstract

In this paper, the 3rd generation localization protection is different from the working environment of traditional protection system, which leads to the special structure of the localization protection device. This paper establishes the reliability analysis model of the grounding protection for the combination and operation characteristics of the centralized protection device. And the evaluation index, based on this, the fault tree and Monte Carlo simulation are used to jointly solve the problem, and the reliability of the planned protection device is analyzed.

Published
2019

19. Analysis of Transformer Abnormal Heating Based on Infrared Thermal Imaging Technology

Author

Zhang Zhenyu, Li Yongxiang, Zhang Shen, Liu Zhixiang, Chen Qingsong, and Wu Zhiyuan

Subjects
Infrared, Computer science, 020209 energy, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, Troubleshooting, law.invention, law, Thermal, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, Infrared thermal imaging, Imaging technology, Infrared heater, Transformer, Power equipment
Abstract

With the development of infrared heating thermal imaging technology, it plays more and more important role in fault diagnosis of power equipment. In order to facilitate on-site troubleshooting of power transformers, this paper firstly introduces the structure of common faults locations (Military Cap and end screen) and then analyzes common heating faults of transformers combined with practical cases using infrared detection technology. It can be seen that infrared detection technology is very convenient and practical for transformer fault diagnosis.

Published
2018

24. Electromagnetic vibration analysis of double redundancy permanent magnet synchronous motors in two modes

Author

Yu Hua, Li Guodong, Liu Zhixiang, Zheng Zhihong, and Wu Zhiyuan

Subjects
Electromagnetic field, Physics, Electromagnetic vibration, Modal, Permanent magnet synchronous motor, Electromagnetic coil, Acoustics, Structure design, Redundancy (engineering), Thermal coupling
Abstract

Double redundancy permanent magnet synchronous motor (DRPMSM) is used in the occasion which has higher reliability requirement. In the paper, the electromagnetic vibration of fractional-slot concentrated windings dual-redundancy permanent magnet synchronous motor of 10-pole/12-slot with low thermal coupling and non-electromagnetic coupling between windings in two modes which includes double-redundancy working and single-redundancy working, was investigated and simulated. Electromagnetic field and force, motor modal and electromagnetic vibration were researched in orders. The differences between them were analyzed. The results can offer guides for the structure design of DRPMSM.

Published
2017

25. Adaptive Path Following Control of Unmanned Surface Vehicles Considering Environmental Disturbances and System Constraints.

Author

Liu, Zhixiang, Zhang, Youmin, Yuan, Chi, and Luo, Jun

Subjects
*ECOLOGICAL disturbances, *STEERING gear, *REMOTELY piloted vehicles, *ADAPTIVE control systems, *STATE feedback (Feedback control systems)
Abstract

The current maritime applications have yielded strong demands for the development of advanced unmanned surface vehicles (USVs) with more reliable path following capabilities to greatly extend mission durations and enhance accommodative capabilities of USVs to more hazardous and dynamic environments. This paper presents an adaptive path following control method using a retrofit adaptive tracking control technique with application to a USV with consideration of environmental disturbances (like winds, waves, and currents), while taking into account of the system constraints of USVs, including both turning features (turning rate limit and turning dynamics) and rudder operation constraints (rudder deflection and rate saturation, and its dynamics). In order to guarantee the satisfactory performance of the USV operating in a calm environment, a baseline state feedback tracking controller considering the characteristics of yaw rate and rudder operations, and USV steering and actuator dynamics is first designed. In the presence of time-varying environmental disturbances, a retrofit adaptive disturbance compensating control mechanism is then developed based on the disturbance amplitude estimated from an indirect adaptive disturbance estimator. Finally, a reconfigurable adaptive path following controller is synthesized by combining the baseline controller and the adaptive disturbance compensating mechanism for the proper operation of the USV in the presence of environmental disturbances, while the desired path is successfully followed by the USV within an acceptable deviation boundary and without violating constraints of turning rates as well as amplitude and rate of rudder deflections. To evaluate the effectiveness of the proposed path following control methodology, both numerical simulations on a nonlinear USV model and field experiments on a real-size USV are conducted. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

26. A review and prospect for temperature control strategy of water-cooled PEMFC

Author

Zhe Han, Zhuo Niu, Liu Zhixiang, and Li He

Subjects
Cold start (automotive), Engineering, Temperature control, business.industry, 020209 energy, Water cooled, Critical factors, Mechanical engineering, Proton exchange membrane fuel cell, 02 engineering and technology, 021001 nanoscience & nanotechnology, Coolant, Stack (abstract data type), 0202 electrical engineering, electronic engineering, information engineering, Fuel cells, 0210 nano-technology, Process engineering, business
Abstract

Temperature is one of the critical factors affecting the performance of proton exchange membrane fuel cell (PEMFC). The temperature control of PEMFC mainly includes cold start and thermal management. A reasonable thermal management system and fast cold start method can effectively manage the temperature of fuel cell, improve its performance and prolong life. On the contrary, it is entirely possible to reduce the PEMFC tolerance, persistence and other output performance, even give rise to experimental safety accidents in serious cases. In this paper, research on the cold start and thermal management strategies of PEMFC is reviewed, and how to control the temperature of stack quickly and effectively is discussed while analyses and summary on the temperature control strategies are made.

Published
2017

41. An assessment method for reliability of distributed control system

Author

Siyan Xu, Liu Zhixiang, Lei Yun, and Dan Li

Subjects
Reliability theory, symbols.namesake, Computer science, Assessment methods, symbols, Markov process, Control engineering, Markov model, Distributed control system, Object (computer science), Decentralised system, Reliability (statistics), Reliability engineering
Abstract

Combined with the distributed control system operating characteristics, this paper proposed a reliability assessment method based on the Markov models. First, determine the assessment of the object and its components, and components formal description. Then we can build the Markov models theory of distributed control system reliability evaluation model, using the model to assess the reliability. At last we use the confidence level theory to judge the results of the assessment. Application results of a chemical industry distributed control system shows that this method can effectively assess the reliability of distributed control systems.

Published
2015

42. An adaptive linear parameter varying fault tolerant control scheme for unmanned surface vehicle steering control

Author

Luo Jun, Yuan Chi, Zhang Youmin, and Liu Zhixiang

Subjects
Engineering, Adaptive control, Control theory, business.industry, Linear matrix inequality, Control reconfiguration, Control engineering, Fault tolerance, Actuator, Fault (power engineering), business, Stability (probability)
Abstract

This paper proposes an adaptive linear parameter varying (LPV) fault tolerant control approach with application to an unmanned surface vehicle (USV) steering control. First, an LPV baseline controller is designed to guarantee the acceptable tracking performance and stability of USV under time-varying operating states (distinct surge speed). Then, an adaptive fault estimation and compensating control mechanism combining with the baseline control strategy are synthesized to asymptotically stabilize the closed-loop system in the presence of actuator faults. Ultimately, simulations are conducted to validate the effectiveness of the proposed control methodology on a USV nonlinear model in the presence/absence of actuator faults and surge speed.

Published
2015

43. Distributed Finite-Time Fault-Tolerant Containment Control for Multiple Unmanned Aerial Vehicles.

Author

Yu, Ziquan, Liu, Zhixiang, Zhang, Youmin, Qu, Yaohong, and Su, Chun-Yi

Subjects
*LYAPUNOV stability, *GRAPH theory, *DRONE aircraft, *VERTICALLY rising aircraft, *STABILITY theory
Abstract

This paper investigates the distributed finite-time fault-tolerant containment control problem for multiple unmanned aerial vehicles (multi-UAVs) in the presence of actuator faults and input saturation. The distributed finite-time sliding-mode observer (SMO) is first developed to estimate the reference for each follower UAV. Then, based on the estimated knowledge, the distributed finite-time fault-tolerant controller is recursively designed to guide all follower UAVs into the convex hull spanned by the trajectories of leader UAVs with the help of a new set of error variables. Moreover, the unknown nonlinearities inherent in the multi-UAVs system, computational burden, and input saturation are simultaneously handled by utilizing neural network (NN), minimum parameter learning of NN (MPLNN), first-order sliding-mode differentiator (FOSMD) techniques, and a group of auxiliary systems. Furthermore, the graph theory and Lyapunov stability analysis methods are adopted to guarantee that all follower UAVs can converge to the convex hull spanned by the leader UAVs even in the event of actuator faults. Finally, extensive comparative simulations have been conducted to demonstrate the effectiveness of the proposed control scheme. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

44. Wirelessly Operated, Implantable Optoelectronic Probes for Optogenetics in Freely Moving Animals.

Author

Zhao, Yu, Liu, Changbo, Liu, Zhixiang, Luo, Wenhan, Li, Lizhu, Cai, Xue, Liang, Dong, Su, Yuanzhe, Ding, He, Wang, Qiang, Yin, Lan, Guan, Jisong, Luo, Minmin, and Sheng, Xing

Subjects
INDIUM gallium nitride, OPTOGENETICS, BRAIN-computer interfaces, ANIMAL behavior, BRAIN stimulation, ANIMAL mechanics
Abstract

Recording and interrogating brain activities using optical methods have become emerging technologies in neuroscience. Traditional tools for optogenetic stimulation in the deep brain are mostly based on implantable fibers, imposing constraints on the animal movement. Recently developed microscale light-emitting diodes (micro-LEDs), which can be wirelessly operated, serve as injectable light sources that directly interact with neural systems. Here, we exploit a wirelessly controlled, implantable system for optogenetic studies in behaving animals. Thin-film indium gallium nitride (InGaN)-based blue micro-LEDs transferred onto flexible probes are injected into the animal brain and optically activate channelrhodopsin-2 expressing neurons. A customized circuit module with a battery is employed to modulate the micro-LED, which is remotely controlled at a distance up to 50mvia 2.4-GHz radio frequency communications. The systems are implemented on freely moving mice, and demonstrate optogenetic modulation of locomotive behaviors in vivo. Moreover, independent and synchronous control of multiple animals is accomplished with the communication unit in the design circuit. The proposed system provides the potential for advanced optical neural interfaces and offers solutions to study complicated animal behaviors in neuroscience research. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results