Coordinated Control System Research Articles

A dynamic nonlinear model for a wide-load range operation of ultra-supercritical once-through boiler-turbine units

As the penetration of renewable energy generation increases in power grid, ultra-supercritical (USC) once-through boiler-turbine (OTBT) units are required to operate in a wide load range to maintain the grid stability. Coordinated control system (CCS) coordinates boiler and turbine systems to track load demand and ensure safe and economical operation simultaneously. However, few studies focus on modeling the USC-OTBT units for CCS design under the current stringent requirement. This study develops a dynamic nonlinear model of a USC-OTBT unit operating in a wide load range, which is a first step toward designing an effective CCS. This work first analyzes and captures the nonlinear characteristics of the USC-OTBT unit in low load and extends to model the dynamic process of the unit in a wider load range, from low load to full load. Besides, two energy functions are presented by analyzing open-loop responses to improve the model structure and dynamic modeling accuracy. Model structure is derived from mass and energy conservation laws, and model parameters and functions are identified based on running data. Validation results demonstrate the effectiveness of the model for a wide load range operation of the USC-OTBT unit, providing a basis for an effective CCS design.

A geographic routing protocol based on trunk line in VANETs

A Trunk Line Based Geographic Routing(TLBGR) protocol in Vehicular Ad-hoc Networks (VANETs) is proposed in this paper to solve the problem of data acquisition in the traditional trunk coordinated control system. Because of the characteristics of short communication time and high packet loss among vehicles, the vehicles entering the trunk lines can not transmit their information to the trunk coordinated control system stably. To resolve this problem, the proposed protocol uses the trunk lines’ traffic flow and the surrounding road network to provide a real-time data transmission routing scheme. It takes into account the data congestion problem caused by the large traffic flow of the main roads, which leads to the corresponding increase of the information flow of the section and the package loss, and the link partition problem caused by the insufficient traffic flow, which makes the vehicles have to carry and relay information thus increasing the transmission delay. The proposed TLBGR protocol can be divided into two stages: the next-intersection selection, and the next-hop selection in the chosen path between the current and next intersections. Simulation results show that, compared with other IoT routing protocols including Greedy Perimeter Stateless Routing (GPSR), Ad-hoc On Demand Vector (AODV), and Q-AODV, the TLBGR protocol has better performance in aspects of end-to-end delay, delivery rate, and routing cost under the scenario of urban traffic trunk lines. The TLBGR protocol can effectively avoid data congestion and local optimum problems, increase the delivery rate of data packets, and is therefore suitable for the routing requirements in this application scenario.

Improved Coordinated Control of Coal-fired Power Units with Large-scale Renewable Energy Integration by Introducing Battery Energy Storage System

With a high proportion of renewable energy being connected to the grid, the stable operation of the power system has been severely challenged. Conventional coal-fired power units need to take measures to compensate for random fluctuations in renewable power generation. This study introduces the battery energy storage system (BESS) to the coordinated control system (CCS) of the coal-fired units to improve the load regulation. Firstly, the dynamic models of boiler-turbine unit and BESS are set up. Furthermore, an improved coordinated control system combined with boiler, turbine, and BESS is designed. A dual controller that consists of BESS and fuel control is proposed to improve the power ramp rate. Finally, a power step simulation in a 330 MW coal-fired power unit is conducted. The simulation results show that the power ramp rate is 60 MW/min and the AGC performance index reaches 7.68 with the improved strategy.

Source-Network-Load-Storage Coordinated Control System Based on Distribution IOT Cloud Platform and Virtual Power Plant

In view of the distribution network operation problems caused by many distributed generations integration to distribution network, and the increasingly serious peak valley imbalance in grid, this paper proposes a coordinated control system of source-network-load-storage based on virtual power plant technology, which is designed and implemented in the actual project. The system uses cloud platform technology and multi-energy complementary technology to realize coordination and optimization control mechanism between sources, network and loads in regional distribution network. The system is based on the distribution Internet of things cloud master platform. Through the virtual power plant technology, resources such as cogeneration, photovoltaic, wind, distributed energy storage, electric vehicles, flexible loads are aggregated to achieve coordinated and unified control, realize the optimal operation of multi-energy complementary. It can accept the control of the dispatching center, and participate in the power transaction of demand response. Based on the application scenario, this paper explains how to use virtual power plant technology to participate in demand response power transaction, and describes the transaction rules and processes. The system is beneficial to the safety and reliability of the distribution network. It can implement reasonable configuration and consumption of distribution generations. It can control controllable loads such as electric vehicle charging pile to participate in peak regulation of power grid, and provide strong technical support for the realization of demand response.

Coordination of Lateral Vehicle Control Systems Using Learning-Based Strategies

The paper proposes a novel learning-based coordination strategy for lateral control systems of automated vehicles. The motivation of the research is to improve the performance level of the coordinated system compared to the conventional model-based reconfigurable solutions. During vehicle maneuvers, the coordinated control system provides torque vectoring and front-wheel steering angle in order to guarantee the various lateral dynamical performances. The performance specifications are guaranteed on two levels, i.e., primary performances are guaranteed by Linear Parameter Varying (LPV) controllers, while secondary performances (e.g., economy and comfort) are maintained by a reinforcement-learning-based (RL) controller. The coordination of the control systems is carried out by a supervisor. The effectiveness of the proposed coordinated control system is illustrated through high velocity vehicle maneuvers.

Improving the CCS performance of coal-fired drum boiler units base on PEB and DEB strategies

This paper proposes a coordinated control system (CCS) for a coal-fired drum boiler unit based on precise energy balance (PEB) and direct energy balance (DEB) strategies. Firstly, considering the boiler energy storage is extremely complex, this paper proposes a drum boiler model with clear physical meaning. Based on the model, the boiler energy storage is further tested and analyzed. Secondly, considering several key parameters, a PEB strategy for feedforward control is proposed. Combined with the DEB strategy and load command (LDC) reconstruction, the CCS of the unit is designed. Simulation results show that the PEB strategy can achieve precise feedforward control, the LDC reconstruction can greatly improve the evaluation indicators of the unit load, and the CCS can adapt well to changes in coal quality and boiler energy storage. Application results show that the unit load can track its set point well under small and large ranges of load swing. The ramp rate is up to 13.2MW/min, the load accuracy is less than 1.2MW/min, the response time is less than 22s, and the comprehensive indicator is up to 4.35. Therefore, the CCS can be highly adapted to the dispatching demand of power grid. In addition, the boiler combustion is stable, the max deviations of steam pressure and temperature are 0.7MPa and 6.4°C, respectively.

Adaptive and multi-path progression signal control under connected vehicle environment

Through wireless communications, enriched information from connected vehicles (CVs) can describe traffic information near an intersection and would supplement a data source for an effective signal control. This paper proposes an adaptive traffic signal control system in a CV environment. At the intersection level, an adaptive control model is developed to assign optimal green times by minimizing the total vehicle delay. When the CV penetration rate is low, a method depending on limited CV data is presented to estimate the vehicle arrival information. At the corridor level, a real-time optimization model is formulated to design the dynamic progression plan for critical paths (i.e. paths with high flows). These two optimization models are solved by the dynamic programming technique. A real-world arterial is modeled in VISSIM to evaluate the effectiveness and efficiency of the proposed traffic signal control system. Simulations with various CV penetration rates and demand levels are conducted to compare the proposed system with fixed coordination and adaptive signal control systems. Results indicate that the proposed system outperforms both base systems by reducing 15.67% and 13.81% of the average delay, respectively, when the CV penetration rate is relatively high. Moreover, the proposed system can improve the arterial performance under all tested scenarios with various CV penetration rates and demand levels. Since the tested demand scenarios can reflect the real traffic fluctuations, it can be proved that the proposed control system could be applied in the field to boost the overall traffic efficiency along the arterial.

Compensation Design of Coordinated Control System for Supercritical Once-Through CHP Plants Based on Energy Analysis

To increase the flexibility of power generation, the supercritical once-through boiler combined heat and power (CHP) plant should improve its coordinated control system (CCS). The difficulty of CCS for supercritical once-through boiler unit is to determine the water-fuel ratio in the dynamic process. First, a CHP unit model is established and simplified into a three-input three-output object under pure condensing working conditions. Second, dynamic relative matrix gain method and simulation is used to analysis several once-through boiler coordinated control schemes commonly used in engineering in which the compensation link is designed on the basis of water-fuel ratio. Simulation results show that, the water following CCS scheme has better intermediate point temperature performance and worse throttle pressure performance than the fuel following CCS scheme. To improve pressure performance, the closed-loop characteristics of pressure response to fuel and feed water flow are analyzed and compared through wavelet analysis. Finally, a method for determining the inertia time constant in the dynamic compensation link by comparing the wavelet coefficients is proposed. Wavelet analysis show that the imbalance in the speed of energy changes to fuel and feed water flow is the essential cause of large fluctuations in intermediate point temperature and throttle pressure before turbine of the supercritical once-through boiler unit. Simulation results show that using the proposed dynamic compensation in water following CCS can effectively reduce fluctuations of the intermediate point temperature and fluctuations of throttle pressure before turbine when power load command changes.

The Key technologies for the construction of resilient distribution networks under the background of smart grids

When the power grid faces sudden extreme events, large-scale blackouts have caused huge economic losses. At the same time, under the development of smart grid, the research of resilient distribution network has received more extensive attention. This article introduces the connotations and concepts of resilient distribution networks in the context of smart grids, and expands the connotations of resilient grids. In addition to the resilience of physical strength under extreme disasters, it also proposes market resilience under the laws of market economy and normal operation mode. This article also introduces several key technologies for improving the resilience of power grids, including intelligent self-sensing power reserve system, adjustable flexible load, source-grid-load-storage coordinated control system, online intelligent diagnosis of power cables, and Operation and maintenance, describes the principles and functions of these technologies in building resilient power grids. The article describes from the perspectives of prevention before disasters and recovery when disasters occur.

A Bioinspired Soft Robot Combining the Growth Adaptability of Vine Plants with a Coordinated Control System.

Tip-extending soft robots, taking flexible film or rubber as body material and fluid pressure as input power, exhibit excellent advantages in constrained and cluttered environments for detection and manipulation. However, existing soft continuum robots are of great challenges in achieving multiple, mutually independent, and on-demand active steering over a long distance without precise steering control. In this paper, we introduce a vine-like soft robot made up of a pressurized thin-walled vessel integrated with the high controllability of a control system with multiple degrees of freedom in three dimensions. Moreover, steering and kinematic models to relate the steering angle and robot length to the location of the robot tip are provided, and a dynamic finite element model for analyzing the motion of the spatial consecutive steering is established. We demonstrate the abilities of disinfection of the robot moving in a long and tortuous pipeline and detection in a multi-obstacle constrained environment. It is established that the robot exhibits great advantages in active consecutive steering over a long distance, high controllability in completing more complex path planning, and significant ability of carrying operational tools for ventilation pipeline disinfection and multi-obstacle detection. The bionic soft robot shows great promise for use in environment sensing, target detecting, and equipment servicing.

Design of prosthetics and orthotics based on muscular coordination control system

Design of prosthetics and orthotics based on muscular coordination control system

Flexibility Enhancement for Coordinate Control System of 1000MW Ultra-Supercritical Unit by Optimized Error-Based ADRC Approach

Flexibility Enhancement for Coordinate Control System of 1000MW Ultra-Supercritical Unit by Optimized Error-Based ADRC Approach

Coordinate-based control for a materials handling equipment utilizing real-time simulation

This paper presents the development and implementation of an advanced control system for a hydraulic manipulator. Designing a suitable coordinate control system for materials handling machines is vital for desired machine performance. For this purpose, targets of developing a proper coordinate control system were defined and mathematical equations were formulated. The two common control methods, i.e. open-loop control and closed-loop control were specifically designed for the handler in question, and the performance of the machine was studied applying each control method. The simulation environment and the operation principle of the created models are discussed in detail in this paper. The two control strategies introduced were tested through real-time simulation, and the accuracy and the performance of the manipulator were investigated utilizing each control method. The limitations and problems of each control strategy are addressed, and suggestions for further research directions to improve the accuracy of tip control are recommended. The case study in this paper is a mobile harbor crane material handler provided by the Mantsinen Group.

Multi-modal human-computer interaction system in cockpit

In order to explore new human-machine interaction methods, a set of multi-modal human-machine interaction coordinated control system is proposed, which realizes the basic flight control based on the change of the pilot’s field of view, touch control, voice control and other information obtained from multi-mode coordinated control. This system introduces a new type of human-computer interaction into the cockpit application on the basis of the human-computer interaction interface for flight driving, and has carried out research on multi-mode collaborative control system, mainly including eye movement interaction, touch interaction gesture Interaction and voice interaction. Finally, this project formed a multi-mode cooperative control software and hardware system.

AUTOMATIC SYNTHESIS OF PETRI NETS AT TUNING UP OF THE COORDINATING AUTOMATIC CONTROL SYSTEMS

The process of automated tuning for the coordinating automatic control system is considered in this paper. This process of tuning for the coordinating control system is linked to the automatic synthesis of Petri nets based on functioning of the artificial neural network. Thereby, we can automate the process of tuning and synthesis of system models and also solve the urgent task linked to the minimization of tuning time for the multilevel control systems. The purposes of the scientific work are time reduction of the tuning and automatization of the tuning for the multilevel coordinating systems of the automatic control. In order to achieve this purpose in the MATLAB \ Simulink software environment it is necessary to devel- op the system for automated tuning of the regulators of various levels for the coordinating automatic control system. The application of artificial neural network with automatic synthesis of Petri nets allows to introduce intelligent technology in the automated tuning system. In this work we have presented the corresponding block diagrams of considered automated tuning system and the principles of its functioning. The certain principle of the formation of Petri nets is proposed. These Petri nets represent the algorithms of tuning in the systems for analysis the corresponding processes. The formation of the composition in the scheme from Petri net during the functioning of the artificial neural network is presented in the paper. The results of experiment are presented in the final part of this work. This time characteristics of the pro- cess of setting up for the coordinating automatic control system of foodstuffs cooling in tunnel chamber. The experiments were conducted in the Matlab 2012a environment. Based on the results of the experiment we have depicted the process of synthesis of the Petri net representing the system tuning algorithm. The performed experiments have showed the principal suitability of the automated search system for the settings of the regulators of various levels of the coordinating control system. The technique of automatic synthesis of Petri nets based on the functioning of artificial neural networks has obtained the further devel- opment while performing the approved task in the scientific paper.

Modeling method of steam turbine generator set based on cascade feedforward PID coordinated control system

Objective In order to quickly and accurately evaluate the reliability of a steam turbine generator set under actual working conditions, it is necessary to construct a visual model of the set. Method Based on an analysis of a mathematical model of a traditional steam turbine generator set, a cascade PID method is proposed and a feedforward link added. Then, based on a Matlab Simulink environment, a visual model of the optimized control of a steam turbine generator set is built, and the steady state and fault state of the set are simulated and analyzed with the help of the simulated fault module. Results The simulation results show that the output speed of the steam turbine generator set based on cascade feedforward PID coordinated control is higher than the given speed for a short time when starting under load, but the stable value is quickly restored under the action of the control feedback. In the case of failure, the rotation speed can also fluctuate within a given range. Conclusion This modeling method of a steam turbine generator set based on a cascade feedforward PID coordinated control system can be popularized in the modeling of nuclear turbine propulsion systems, providing an analytical means of achieving the visual analysis of the unit's operation state, and saving both cost and time.

Countering FDI Attacks on DERs Coordinated Control System Using FMI-Compatible Cosimulation

In this article, the resilience of a coordinated control system for a set of PV-based distributed energy resources (DERs) against false data injection (FDI) attacks is evaluated. The evaluation is performed using a functional mock-up interface (FMI)-compatible cosimulation platform which enables the interaction of multi-domain simulators (EMTP, MATLAB/Simulink, and NS-3). The cosimulation platform permits rigorous analysis of cybersecurity through detailed modeling of all system components. The DER coordinated control and communication systems implemented on the IEEE-34 bus benchmark consist of measurement, control and monitoring components including substation central controller, DER local controllers, synchrophasor network and advanced metering infrastructure (AMI). Some DERs are equipped with an energy storage system (ESS) and coordinated by the central control unit in order to correct voltage disturbances resulting from the intermittent solar photovoltaic (PV) generation. The FDI attack targets the AMI system and aims at manipulating the load profile messages reported by the smart meter collector, thus yielding a central control failure. To detect the attacks and mitigate their impacts, a neural network-based algorithm is proposed and incorporated in the central control unit. The effectiveness of the proposed detection and mitigation algorithm is confirmed through simulations using the proposed FMI-compatible cosimulation platform.

The control‐oriented model of coordinated control system based on stochastic differential equations

AbstractConsidering the large‐scale development of renewable energy resources globally, control optimization of coal‐fired power plants is becoming increasingly crucial. The dynamics of the coordinated control system (CCS) must be studied prior to designing a controller. These dynamics of the subcritical units have been expressed through various modeling methods. However, in previous studies, ordinary differential equations (ODEs) have been primarily employed, which cannot reflect the uncertainties in the system. Therefore, a model with a greater accuracy should be observed to comprise uncorrelated residuals. In this study, the uncertainties in the calorific value of fired coal and combustion process were analyzed first. A normal distribution of disturbance was assumed in this process. The dynamics of the CCS were then described with stochastic differential equations (SDEs). Furthermore, a parameter estimation procedure was designed. The residual evaluation is employed to improve the model evaluation. After simulations, the SDE‐based model‐3 in this study elucidates the dynamics of the subcritical boiler‐turbine system better than the ODE‐based model and other SDE‐based models. The measured values can be regarded as a possible result of this model, rendering it a potential platform to employ stochastic model predictive control in CCS.

Нечёткое согласованное управление системой электроприводов четырёхколёсного мобильного робота

This paper presents the construction of a fuzzy system controller of a coordinated control system of an electric drive system for a four-wheel mobile robot with two differential drive units. The structure of this system regulator, the rule base, and the expression of the relationship between its elements are shown. In the article the authors show the results of computer experiments in graphs of trajectory error for different configurations of the robot and the system controller coefficient values.

Lane Departure Assistance Coordinated Control System for In-Wheel Motor Drive Vehicles Based on Dynamic Extension Boundary Decision

Aiming at the advantages in active safety control of in-wheel motor drive vehicles, the classified decision-control-execution is proposed to the lane departure assistance system under the premise of ensuring the stability of the vehicle. The dynamic extension boundaries which vary with vehicle speed, road curvature and road adhesion coefficient are designed in the decision layer by using the neural network algorithm, which divides different dangerous degrees into different decision regions. The active differential steering controller, the electronic differential controller and their coordinated control strategy are designed in the control layer, and the corresponding control is carried out among different decision regions. In order to avoid the dangerous situation of secondary deviation caused by the existence of drift angle when the vehicle is rectified to the lane centerline, the heading angle controller is then designed in the control layer. The different torque distribution modes are divided according to the current vehicle speed, road adhesion coefficient and lateral acceleration in the execution layer, and the economic distribution, stability distribution, joint distribution are correspondingly executed among different torque distribution modes. Finally, Carsim and Matlab/Simulink are used for simulation verification.