Design and Implementation of Quench Protection in the EAST Cryogenic Control System

An outline of the complete design of the cryogenic system, including the detection of quench signals, the processing flow after a quench and the concrete measures of pressure release for EAST is described in this paper. The hardware and software configurations on DeltaV DCS are illustrated in detail. The results of quench protection testing in cooling experiments are also analyzed.

Principle, Modeling and Control of DC-DC Convertors for EV

DC DC convertors can convert the EV's high voltage DC power supply into the low voltage DC power supply. In order to design an excellent convertor one must be guided by theory of automatic control. The principle and the method of design, modeling and control for DC DC convertors of EV are introduced. The method of the system response to a unit step function input and the frequency response method are applied to researching the convertor's mathematics model and control characteristic. Experiments show that the designed DC DC convertor's output voltage precision is high, the antijamming ability is strong and the adjustable performance is fast and smooth.

Stability Analysis and Control of DC Distribution System with Electric Vehicles

The DC distribution network system equipped with a large number of power electronic equipment exhibits weak damping characteristics and is prone to low-frequency and high-frequency unstable oscillations.The current interpretation of the oscillation mechanism has not been unified.Firstly,this paper established the complete statespace model of the distribution system consisting of a large number of electric vehicles,characteristic equation of the distribution network system is derived by establishing a state-space model,and simplified reduced-order equations describing the low-frequency oscillation and the high-frequency oscillation are obtained.Secondly,based on eigenvalue analysis,the oscillation modes and the influence of the key system parameters on the oscillation mode are studied.Besides,impacts of key factors,such as distribution network connection topology and number of dynamic loads,have been discussed to suppress oscillatory instability caused by inappropriate design or dynamic interactions.Finally,using the DC distribution example system,through model calculation and time-domain simulation analysis,the correctness of the aforementioned analysis is verified.

Research on Intelligent Control and protection of flexible HVDC

This paper introduces the working principle of HVDC control and protection system. And the paper summarizes the flexible HVDC technology features and application fields and describes the composition and software intelligent flexible HVDC control and protection system configuration. Finally, the simulation results are also given, experimental results show： HVDC flexible intelligent control and protection has a good control effect in the steady state and transient process, suitable for practical engineering application.

Design of BLDCM Driving and Control System for Motorized Treadmill

To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor （BLDCM） driving and control system for motorized treadmill is developed. High integration and reliability of this system are ensured under the condition that intelligent power module （IPM） is used and the protection module is included. Periodic current control method is applied to reduce the average current flowing through the armature winding of the motor when the treadmill is required to start with low speed while large load is added. Piecewise proportion-integration-differentiation （PID） control algorithm is applied to solve the problem of speed fluctuation when impulse load is added. The motorized treadmill of a new generation with the driving and control system has the advantages of high reliability, good speed stability, wide timing scope, low cost, and long life-span. And it is very promising for practical applications.

Optimal Cooperative Secondary Control for Islanded DC Microgrids via a Fully Actuated Approach

DC-DC converter-based multi-bus DC microgrids(MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately portray the electrical characteristics of actual MGs while is controller design-friendly has kept the issue active. To this end, this paper establishes a large-signal model containing the comprehensive dynamical behavior of the DC MGs based on the theory of high-order fully actuated systems, and proposes distributed optimal control based on this. The proposed secondary control method can achieve the two goals of voltage recovery and current sharing for multi-bus DC MGs. Additionally, the simple structure of the proposed approach is similar to one based on droop control, which allows this control technique to be easily implemented in a variety of modern microgrids with different configurations. In contrast to existing studies, the process of controller design in this paper is closely tied to the actual dynamics of the MGs. It is a prominent feature that enables engineers to customize the performance metrics of the system. In addition, the analysis of the stability of the closed-loop DC microgrid system, as well as the optimality and consensus of current sharing are given. Finally, a scaled-down solar and battery-based microgrid prototype with maximum power point tracking controller is developed in the laboratory to experimentally test the efficacy of the proposed control method.

Review of the Configuration and Transient Stability of Large-scale Renewable Energy Generation through Hybrid DC Transmission

Based on the complementary advantages of Line Commutated Converter(LCC)and Modular Multilevel Converter(MMC)in power grid applications,there are two types of hybrid DC system topologies:one is the parallel connection of LCC converter stations and MMC converter stations,and the other is the series connection of LCC and MMC converter stations within a single station.The hybrid DC transmission system faces broad application prospects and development potential in large-scale clean energy integration across regions and the construction of a new power system dominated by new energy sources in China.This paper first analyzes the system forms and topological characteristics of hybrid DC transmission,introducing the forms and topological characteristics of converter-level hybrid DC transmission systems and system-level hybrid DC transmission systems.Next,it analyzes the operating characteristics of LCC and MMC inverter-level hybrid DC transmission systems,provides insights into the transient stability of hybrid DC transmission systems,and typical fault ride-through control strategies.Finally,it summarizes the networking characteristics of the LCC-MMC series within the converter station hybrid DC transmission system,studies the transient characteristics and fault ridethrough control strategies under different fault types for the LCC-MMC series in the receiving-end converter station,and investigates the transient characteristics and fault ride-through control strategies under different fault types for the LCC-MMC series in the sending-end converter station.

Fractional Gradient Descent RBFNN for Active Fault-Tolerant Control of Plant Protection UAVs

With the increasing prevalence of high-order systems in engineering applications, these systems often exhibitsignificant disturbances and can be challenging to model accurately. As a result, the active disturbance rejectioncontroller (ADRC) has been widely applied in various fields. However, in controlling plant protection unmannedaerial vehicles (UAVs), which are typically large and subject to significant disturbances, load disturbances andthe possibility of multiple actuator faults during pesticide spraying pose significant challenges. To address theseissues, this paper proposes a novel fault-tolerant control method that combines a radial basis function neuralnetwork (RBFNN) with a second-order ADRC and leverages a fractional gradient descent (FGD) algorithm.We integrate the plant protection UAV model’s uncertain parameters, load disturbance parameters, and actuatorfault parameters and utilize the RBFNN for system parameter identification. The resulting ADRC exhibits loaddisturbance suppression and fault tolerance capabilities, and our proposed active fault-tolerant control law hasLyapunov stability implications. Experimental results obtained using a multi-rotor fault-tolerant test platformdemonstrate that the proposed method outperforms other control strategies regarding load disturbance suppressionand fault-tolerant performance.

Glucagon-like peptide-1 receptor agonists:Exploring the mechanisms from glycemic control to treatment of multisystemic diseases

This editorial takes a deeper look at the insights provided by Soresi and Giannitrapani,which examined the therapeutic potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)for metabolic dysfunction-associated fatty liver disease.We provide supplementary insights to their research,highlighting the broader systemic implications of GLP-1RAs,synthesizing the current understanding of their mechanisms and the trajectory of research in this field.GLP-1RAs are revolutionizing the treatment of type 2 diabetes mellitus and beyond.Beyond glycemic control,GLP-1RAs demonstrate cardiovascular and renal protective effects,offering potential in managing diabetic kidney disease alongside renin–angiotensin–aldosterone system inhibitors.Their role in bone metabolism hints at benefits for diabetic osteoporosis,while the neuroprotective properties of GLP-1RAs show promise in Alzheimer's disease treatment by modulating neuronal insulin signaling.Additionally,they improve hormonal and metabolic profiles in polycystic ovary syndrome.This editorial highlights the multifaceted mechanisms of GLP-1RAs,emphasizing the need for ongoing research to fully realize their therapeutic potential across a range of multisystemic diseases.

EAST Cryogenic Supervisory and Control System Based on Delta-V DCS

The control system for the Experimental Advanced Superconductive Tokamak （EAST） cryogenic system is designed and constructed based on Delta-V DCS （Distribution Control System）, which consists of engineering workstations, operator workstations, application workstations, redundant controller units, input/output （I/O） cards and a redundant control network. Our task is to design a supervisory and control system to provide the operator interface for control and monitoring, sending alarms, archiving of selected signals, and other routines to analyze realtime and historic data. The hardware configuration, software structure and control algorithms are illustrated in detail in this paper. Hvpothetic oroblems and further research are also mentioned.

Architecture Design for Integrated Wide Area Protection and Control Systems

This paper firstly reviews the recent development in power system protection and control, with special attention paid to the wide-area and integrated protection, in order to look into future development of integration of protection and control for smart grids. This paper mainly reports on the development of integrated wide area protection and control for power systems. The concept of integrated wide area protection and control is introduced, in which a hierarchical protection and control system provides the protection and control of wide area or regional power substations/ plants and their associated power network. The system is mainly divided into three levels, the local, the substation/plant and the wide area/regional protection and control. The integrated functions at each level are described in details with an aim to develop an optimal coordination mechanism between the levels. One of the core elements in the system is the synchronised wide area communication network between the substations and the protection and control system, in which latest communication technology is employed. Another important player in the system is the wide area synchronized protection and control information platform, which not only enables the fusion three line of defence for power system protection and control, but also provides a perfect tool for the application of cloud computing to substations and power networks.

Technology and engineering application of cross area HVDC interconnection system high-precision simulation modeling based on ADPSS

In recent years, a large number of high voltage direct current(HVDC) transmission projects have been connected to AC systems. This has started to have an impact on AC/DC hybrid power grids, particularly receiving terminal power grids. An HVDC system is a large-scale power electronic integrated nonlinear system, and it includes a primary system and a control and protection system. Hence, the precision and degree of detail of HVDC systems directly affect the actual effect of simulation. In recent years, in the case of the normal operation and failure of AC power grids, the abnormal fluctuation and even locking of HVDC systems caused by the inappropriate strategies of the control and protection system component have strongly affected power grids. This has significantly affected the safety and stability of receiving power grids and normal operation. In this study, the actual engineering HVDC control logic provided by a manufacturer is analyzed and simulated based on the user defined component library of the ADPSS electromagnetic transient calculation program, and an HVDC control model based on an actual system is established. The accuracy of the DC control custom model based on ADPSS is verified through the simulation of an actual power grid.

Seismic protection of frame structures via semi-active control:modeling and implementation issues

Theoretical and practical issues concerning the multi-faceted task of mitigating the latero-torsional seismic response of a prototypal frame structure with asymmetric mass distribution are approached, Chevron braces with embedded magnetorheological dampers acting on the interstory drift are used to ensure additional energy dissipation. The semi-active control strategy employed to govern the modification of the damper characteristics via feedback is based on the selection of optimal forces according to a H2/LQG criterion, with respect to which the actual forces are regulated by a clipped-optimal logic. A dynamic observer is used to estimate the state through a non-collocated placement of the acceleration sensors. Several aspects to be addressed throughout the complex process including the design, modelization, and implementation phases of semi-active protection systems are discussed. Finally, experimental results obtained to mitigate the motion induced by ground excitation in a large-scale laboratory prototype, simulating the seismic response of a two-story building, are summarized.

Protection and Quality Control of Wild Chinese Herbal Medicine Resources in Nature Reserves by Taking Longyuwan Scenic Spot Within Funiu Mountain Nature Reserve as an Example

This paper discussed how to protect and control the quality of wild Chinese herbal medicine resources in nature reserves by taking Longyuwan National Forest Park within Funiu Mountain Nature Reserve as an example. Through the combination of three methods including literature review, visiting and investigational studies, and field surveys, the data of investigation, collection and collation were analyzed. According to data of surveys, collection and collation, problems related to the protection of wild Chinese herbal medicine resources faced by Longyuwan Scenic Spot within Funiu Mountain Nature Reserve were also analyzed and protection strategies and quality control of wild Chinese herbal medicine resources in this nature reserve were discussed. It was expected that the results would provide important scientific references for the sustainable development, protection and quality control of wild Chinese herbal medicine resources within nature reserves.

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.

Immobilization of antibodies on the self-assembled monolayer by antigen-binding site protection and immobilization kinetic control

The orientation of the biological molecule immobi-lized on a solid surface has been critical in devel-opment of various applications. In this study, ori-entation of antibody was retained by protecting the antigen-binding site of the antibody prior to immo-bilization to -functionalized mixed self-assembled monolayer (SAM) of 12-mercaptododecanoic acid and 1-heptanethiol. More importantly, the number of immobilization bonds formed between each an-tigen-binding site protected antibody molecule and the solid surface was controlled by optimizing the mole fraction of the activated carboxyl group of the linker molecules in the mixed SAM. The amount of antibody used in this study was approximately equivalent to the amount for one monolayer surface coverage. The resulting activity of protected immo-bilized antibody was about 10 fold higher than that of random immobilized

Study on DeviceNet communication mechanism and its application in protection measurement and control system

To fit in with the developing requirement of int and communication of protective relays, a protection egrated functions of protection measurement, control measurement and control system based on DeviceNet fieldbus is designed. The communication mechanism of DeviceNet is studied and data trigger modes, communication connection, message types and other key technologies are analyzed. The object modeling and device description of the device are realized too. Results of network test, dynamic simulation and test in the field indicate that this system can accomplish all the communication tasks in real time and can make precise response to every kind of faults of the motor, transformer, line and capacitor. Moreover, this system has higher measurement precision and better control capability.

Design and Analysis of the Main AC/DC Converter System for ITER

A design of the main AC/DC converter system for ITER is described and the configuration of the main AC/DC converters is presented. To reduce the reactive power absorbed from the converter units, the main AC/DC converters are designed to be series-connected and work in a sequential mode. The structure of the regulator of the converter system is described. A simulation model was built up for the PSCAD/EMTDC code, and the design was validated accordingly. Harmonic analysis and reactive power calculation of the converters units are presented. The results reveal the advantage of sequential control in reducing reactive power and harmonics.

Application of Diagonal Recurrent Neural Network toDC Motor Speed Control Systems

A new kind of dynamic neural network--diagonal recurrent neural network (DRNN) and its learning method and architecture are presented. A direct adaptive control scheme is also developed that is applied to a DC (Direct Current) speed control system with the ability to auto-tune PI (Proportion Integral) parameters based on combining DRNN with PI controller. The simulation results of DRNN show better control performances and potential practical use in comparison with PI controller.