Operation Control Method of Relay Protection in Flexible DC Distribution Network Compatible with Distributed Power Supply

A novel operation control method for relay protection in flexible DC distribution networks with distributed power supply is proposed to address the issue of inaccurate fault location during relay protection,leading to poor performance.The method combines a fault-tolerant fault location method based on long-term and short-term memory networks to accurately locate the fault section.Then,an operation control method for relay protection based on adaptive weight and whale optimization algorithm(WOA)is used to construct an objective function considering the shortest relay protection action time and the smallest impulse current.The adaptive weight and WOA are employed to obtain the optimal strategy for relay protection operation control,reducing the action time and impulse current.Experimental results demonstrate the effectiveness of the proposed method in accurately locating faults and improving relay protection performance.The longest operation time is reduced by 4.7023 s,and the maximum impulse current is limited to 0.3 A,effectively controlling the impact of large impulse currents and enhancing control efficiency.

Operation Control of a High-resolution Plasma Imaging System in KT5D Torus

This paper describes the control software together with the operational hardware, which successfully realizes the operation of a new fully programmable imaging system with high spatial and temporal resolutions on the KT5D magnetic torus, for observing the visible l ight emission from the plasma discharge.

Based on the water source heat pump system operation control and energy consumption optimization

The contradiction between the increasing material demand and resource,is the country has faced problems,to better solve the material demand and the contradiction between the environment and resources,is applied to the development of new energy,new energy,not only can alleviate people and resources,environment and resources,the contradiction between people and the environment,also can promote the sustainable development of world economy,HVAC technology has emerged a new generation of energysaving technology,HVAC has the characteristics of low consumption,low pollution,is a development of technology,to be promoted for environmentfriendly,resource-conserving society has an important role in promoting.This paper focuses on the HVAC technology,water source heat pump system operation control and energy consumption optimization,for the relevant personnel reference.

Design and application of microgrid operation control system based on IEC 61850

We consider the microgrid operation control technology including design of microgrid operation control system,MG control device and control strategy.We pay much attention on microgrid operation control device which is core control device.In order to solve the contradiction of quick speed about microgrid operation mode shift and slow speed about the management system,threelayers control architecture based on IEC61850 is designed and adaptive control strategy is used on MG operation control system.The system has been applied in a distributed generation/energy storage power station.The actual operation shows that the system can be effectively and flexibly connected to distribution network.

Design and Operation Control for Long Campaign Life of Blast Furnaces

At the beginning of 1990s, Shougang blast furnaces （BFs） No. 2, No. 4, No. 3 and No. 1 were rebuilt se quently for new technological modernization in succession. The campaign life of BFs No. 1, No. 3 and No. 4 reaches 16.4, 17.6 and 15.6 years, respectively, and the hot metal output of one campaign reaches 33.8, 35.48 and 26.37 Mt, respectively; the hot metal output of BF effective volume of one campaign reaches 13328, 13991 and 12560 t/m^3, respectively, which reaches the international advanced level of BF high efficiency and long campaign life. In BF desig-ning, several advanced BF long campaign technologies were adopted. BF proper inner profile was optimized, reasona- ble inner profile was adopted, and closed circulating soften water cooling technology was applied in 4 BFs. Double row cooling pipe high efficiency cooling stave was developed which could prolong the service life of bosh, belly and stack. Hot pressed carbon brick and ceramic cup hearth lining structure were applied and optimized. BF operation was improved continuously to ensure stable and smooth operation of BF. Hearth working condition control was strengthened, burden distribution control technology was applied to achieve reasonable distribution of gas flow, and heat load monitoring was strengthened to maintain BF reasonable working inner profile. Proper maintenance at the end of BF campaign was enhanced. Hearth and bottom service life was prolonged by adding titaniferous material and enhancing hearth cooling. Gunning of lining was carried out periodically for the area above tuyere zone.

Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

Electric power conversion system （EPCS）, which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine （DD-WT）. However, this component accounts for the most failures （approximately 60% of the total number） in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring （CM） and fault diagnostics （FD）. Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.

Control of seismic and operational vibrations of rotating machines using semi-active mounts

A dual isolation problem for rotating machines consists of isolation of housing structures from the machine vibrations and protection of machines during an earthquake to maintain their functionality. Desirable characteristics of machine mounts for the above two purposes can differ significantly due to difference in nature of the excitation and performance criteria in the two situations. In this paper, relevant response quantities are identified that may be used to quantify performance and simplified models of rotating machines are presented using which these relevant response quantities may be calculated. Using random vibration approach with a stationary excitation, it is shown that significant improvement in seismic performance is achievable by proper mount design. Results of shaking table experiments performed with a realistic setup using a centrifugal pump are presented. It is concluded that a solution to this dual isolation problem lies in a semi-active mount capable switching its properties from ‘operation-optimum’ to ‘seismic-optimum’ at the onset of a seismic event.

A mathematical model for optimized operation and controlin a CDQ-Boiler system

Based on analyzing the thermal process of a CDQ （coke dry quenching）-Boiler system, the mathematical model for opti-mized operation and control in the CDQ-Boiler system was developed. It includes a mathematical model for heat transferring process in the CDQ unit, a mathematical model for heat transferring process in the boiler and a combustion model for circulating gas in the CDQ-Boiler system. The model was verified by field data, then a series of simulations under several typical operating conditions of CDQ-Boiler were carried on, and in turn, the online relation formulas between the productivity and the optimal circulating gas, and the one between the productivity and the optimal second air, were achieved respectively. These relation equations have been success- fully used in a CDQ-Boiler computer control system in the Baosteel, to realize online optimized guide and control, and meanwhile high efficiency in the CDQ-Boiler system has been achieved.

Research on Controlled Volume Operation Method of Large-scale Water Transfer Canal

The controlled volume method of operation is especially suitable for large-scale water delivery canal system with complex operation requirements. An operating simulation model based on the storage volume control method for multi-reach canal system in series was established. In allusion to the deficiency of existing controlled volume algorithm, the improved controlled volume algorithm of the whole canal pools was proposed, and the simulation results indicated that the storage volume and water level of each canal pool could be accurately controlled after the improved algorithm had been adopted. However, for some typical discharge demand operating conditions, if the previously mentioned algorithm was adopted, then it certainly would cause some unnecessary gate adjustments, and consequently the disturbed canal pools would be increased. Therefore, the idea of controlled volume operation method of continuous canal pools was proposed, and corresponding algorithm was designed. Through simulating practical project, the results indicated that the new controlled volume algorithm proposed for typical operating conditions could comparatively and obviously reduce the number of regulated check gates and disturb canal pools for some typical discharge demand operating conditions, thus the control efficiency of canal system could be improved.

Development of a Novel Feedforward Neural Network Model Based on Controllable Parameters for Predicting Effluent Total Nitrogen

The problem of effluent total nitrogen(TN)at most of the wastewater treatment plants(WWTPs)in China is important for meeting the related water quality standards,even under the condition of high energy consumption.To achieve better prediction and control of effluent TN concentration,an efficient prediction model,based on controllable operation parameters,was constructed in a sequencing batch reactor process.Compared with previous models,this model has two main characteristics:①Superficial gas velocity and anoxic time are controllable operation parameters and are selected as the main input parameters instead of dissolved oxygen to improve the model controllability,and②the model prediction accuracy is improved on the basis of a feedforward neural network(FFNN)with algorithm optimization.The results demonstrated that the FFNN model was efficiently optimized by scaled conjugate gradient,and the performance was excellent compared with other models in terms of the correlation coefficient(R).The optimized FFNN model could provide an accurate prediction of effluent TN based on influent water parameters and key control parameters.This study revealed the possible application of the optimized FFNN model for the efficient removal of pollutants and lower energy consumption at most of the WWTPs.

Challenges and opportunities of machine learning control in building operations

Machine learning control(MLC)is a highly flexible and adaptable method that enables the design,modeling,tuning,and maintenance of building controllers to be more accurate,automated,flexible,and adaptable.The research topic of MLC in building energy systems is developing rapidly,but to our knowledge,no review has been published that specifically and systematically focuses on MLC for building energy systems.This paper provides a systematic review of MLC in building energy systems.We review technical papers in two major categories of applications of machine learning in building control:(1)building system and component modeling for control,and(2)control process learning.We identify MLC topics that have been well-studied and those that need further research in the field of building operation control.We also identify the gaps between the present and future application of MLC and predict future trends and opportunities.

A train timetable rescheduling approach based on multi-train tracking optimization of high-speed railways

Purpose–This paper aims to propose a train timetable rescheduling(TTR)approach from the perspective of multi-train tracking optimization based on the mutual spatiotemporal information in the high-speed railway signaling system.Design/methodology/approach–Firstly,a single-train trajectory optimization(STTO)model is constructed based on train dynamics and operating conditions.The train kinematics parameters,including acceleration,speed and time at each position,are calculated to predict the arrival times in the train timetable.A STTO algorithm is developed to optimize a single-train time-efficient driving strategy.Then,a TTR approach based on multi-train tracking optimization(TTR-MTTO)is proposed with mutual information.The constraints of temporary speed restriction(TSR)and end of authority are decoupled to calculate the tracking trajectory of the backward tracking train.The multi-train trajectories at each position are optimized to generate a timeefficient train timetable.Findings–The numerical experiment is performed on the Beijing-Tianjin high-speed railway line and CR400AF.The STTO algorithm predicts the train’s planned arrival time to calculate the total train delay(TTD).As for the TSR scenario,the proposed TTR-MTTO can reduce TTD by 60.60%compared with the traditional TTR approach with dispatchers’experience.Moreover,TTR-MTTO can optimize a time-efficient train timetable to help dispatchers reschedule trains more reasonably.Originality/value–With the cooperative relationship and mutual information between train rescheduling and control,the proposed TTR-MTTO approach can automatically generate a time-efficient train timetable to reduce the total train delay and the work intensity of dispatchers.

Research on Active Safety Methodologies for Intelligent Railway Systems

Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing the goals of efficiency,convenience,economy,and environmental friendliness.This paper describes the state of the art and proposes a system architecture for intelligent railway systems.It also focuses on the development of railway safety technology at home and abroad,and proposes the active safety method and technology system based on advanced theoretical methods such as the in-depth integration of cyber–physical systems(CPS),data-driven models,and intelligent computing.Finally,several typical applications are demonstrated to verify the advancement and feasibility of active safety technology in intelligent railway systems.

Review of Operational Control Strategy for DC Microgrids with Electric-hydrogen Hybrid Storage Systems

Hydrogen production from renewable energy sources(RESs)is one of the effective ways to achieve carbon peak and carbon neutralization.In order to ensure the efficient,reliable and stable operation of the DC microgrid(MG)with an electric-hydrogen hybrid energy storage system(ESS),the operational constraints and static dynamic characteristics of a hydrogen energy storage system(HESS)needs to be fully considered.First,different hydrogen production systems,using water electrolysis are compared,and the modeling method of the electrolyzer is summarized.The operational control architecture of the DC MG with electric-hydrogen is analyzed.Combined with the working characteristics of the alkaline electrolyzer,the influence of hydrogen energy storage access on the operational mode of the DC MG is analyzed.The operational control strategies of the DC MG with electric-hydrogen hybrid ESS are classified and analyzed from four different aspects:static and dynamic characteristics of the hydrogen energy storage system,power distribution of the electric-hydrogen hybrid ESS and the efficiency optimization of hydrogen energy storage.Finally,the advantages of a modular hydrogen production system(HPS)are described,and the technical problems and research directions in the future are discussed.

Key technologies for medium and low voltage DC distribution system

Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operation of the AC/DC interconnected grid.This paper first summarizes the medium and low voltage DC distribution system schemes and plans put forward by many countries,and then elaborate status of under-construction medium and low voltage DC distribution system project cases in China.Based on these project cases,this paper analyzes key issues involved in the medium and low voltage DC distribution system topologies,equipment,operation control technologies and DC fault protections,in order to provide theoretical and technical reference for future medium and low voltage DC distribution system-related projects.Finally,this paper combines a current China research status to summarize and give a prediction about the future research direction of medium and low voltage DC distribution system,which can provide reference for the research of medium and low voltage DC distribution system.

基于快响空间的地面控制系统设计

结合虚拟任务操作中心思想,提出了构建快响空间地面控制系统的初步设计方案;其方法是融合快响空间任务控制流程和业务应用流程,以"快"为核,以"服务化"云架构为基,构建面向服务的快响空间地面控制系统;最后指出,通过采用虚拟任务操作中心技术,探索了天基信息快速支援地面技术体制创新;通过采用云服务架构及天地安全互联技术,实现用户终端以调用服务的方式远程快速使用资源;通过重构快响空间地面控制流程,实现快响力量的统一控制,协同快速反应;通过采用微服务+容器架构实现任务规划、调度和控制功能的快速构建。

太空快速响应发射场能力建设

为实现战争行动和突发事件的快速响应目的,太空快速响应发射已成为重要的解决手段。总结传统航天发射场面临的挑战,分析了太空快速响应活动对航天发射场的需求,从发射场建设需求体系、发射场测试能力推进、发射场改造和补充建设、天地一体测控通信体系、快速机动发射模式等提出了发射场建设发展途径,为满足太空快速响应发射场系统建设提供有益的技术参考。

重新审视繁文缛节:概念和测量及其三维控制模型

近年来,繁文缛节在学界和管理实践中受到关注和重视的同时也存在某些分歧,厘清其概念内涵对于深化相关研究十分必要。本文从繁文缛节的词源解析出发,基于"有益说—有害说""功能功效说—心理过程模型""客观说—主观说"三种不同视角对繁文缛节观点进行分析讨论,立足学术研究和现实场域对其概念进行科学界定,并对繁文缛节与行政负担、行政延迟、正式化等相关概念进行比较分析,进一步明确了繁文缛节的概念内涵和外延。同时,总结介绍了繁文缛节的概念操作化及其测量,提出繁文缛节三维控制理论模型。最后,结合当前研究进展,提出繁文缛节未来研究的关键领域,并对其在中国的应用前景进行了讨论。文章为繁文缛节研究的理论演进及实践管理者提供了重要的理论基础。

Active source monitoring at the Wenchuan fault zone:coseismic velocity change associated with aftershock event and its implication

With the improvement of seismic observation system, more and more observations indicate that earthquakes may cause seismic velocity change. However, the amplitude and spatial distribution of the velocity variation remains a controversial issue. Recent active source monitoring carried out adjacent to Wenchuan Fault Scientific Drilling （WFSD） revealed unambiguous coseismic velocity change associated with a local M8 5.5 earthquake. Here, we carry out forward modeling using two-dimensional spectral element method to further investigate the amplitude and spatial distribution of observed velocity change. The model is well constrained by results from seismic reflection and WFSD coring. Our model strongly suggests that the observed coseismic velocity change is localized within the fault zone with width of ~ 120 m rather than dynamic strong ground shaking. And a velocity decrease of -2.0 % within the fault zone is required to fit the observed travel time delay distribution, which coincides with rock mechanical experiment and theoretical modeling.

Automatic Train Operation Based on Adaptive Terminal Sliding Mode Control

This paper presents an adaptive terminal sliding mode control(ATSMC) method for automatic train operation. The criterion for the design is keeping high-precision tracking with relatively less adjustment of the control input. The ATSMC structure is designed by considering the nonlinear characteristics of the dynamic model and the parametric uncertainties of the train operation in real time. A nonsingular terminal sliding mode control is employed to make the system quickly reach a stable state within a finite time, which makes the control input less adjust to guarantee the riding comfort. An adaptive mechanism is used to estimate controller parameters to get rid of the need of the prior knowledge about the bounds of system uncertainty. Simulations are presented to demonstrate the effectiveness of the proposed controller, which has robust performance to deal with the external disturbance and system parametric uncertainties. Thereby, the system guarantees the train operation to be accurate and comfortable.