scholarly journals A Decentralized, Flat-Structured Control System for Chiller Plants

2019 ◽  
Vol 9 (22) ◽  
pp. 4811 ◽  
Author(s):  
Dong He ◽  
Qingyu Xiong ◽  
Xuyang Zhang ◽  
Yunchuang Dai ◽  
Ziyan Jiang
Keyword(s):  
Energy Efficiency ◽  
Control System ◽  
Decentralized Control ◽  
Control Method ◽  
Control Strategies ◽  
Measured Data ◽  
Self Organization ◽  
Centralized Control ◽  
Self Recognition

This paper presents a novel control system for chiller plants that is decentralized and flat-structured. Each device in chiller plant system is fitted with a smart node. It is a smart agent, which collects, handles and sends out information to its neighbours. All the smart nodes form a network that can realize self-organization and self-recognition. Different kinds of control strategies can be converted into series of decentralized computing processes carried on by the smart nodes. The principle and mechanism of this decentralized, flat-structured control system for chiller plants are described in detail. Then a case study is presented to show how to build the decentralized, flat-structured control system actually. The measured data shows that the decentralized control method is energy efficiency. Moreover, it is much more flexible and scalable compared with the traditional centralized control method.

scholarly journals Overlapping Decentralized Control Strategies of Building Structures’ Vibration with Time Delay Based on H∞ Control Algorithms under Seismic Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaofang Kang ◽  
Jian Wu ◽  
Yewei Zhang ◽  
Guoliang Liu ◽  
Suhui Zhang ◽  
...  
Keyword(s):  
Control System ◽  
Time Delay ◽  
Vibration Control ◽  
Decentralized Control ◽  
Control Strategy ◽  
Control Algorithm ◽  
Control Method ◽  
Control Strategies ◽  
Linear Matrix ◽  
Feedback Gain

A decentralized control strategy can effectively solve the control problem of the large-scale time delayed structures. In this paper, combining the overlapping decentralized control method, linear matrix inequality (LMI) method, and H∞ control algorithm, overlapping decentralized H∞ control approach of the time delayed structures has been established. The feedback gain matrixes of all subsystems are obtained by this method based on genetic algorithm optimization tools and the specific goal of optimization control. The whole vibration control system of the time delayed structures is divided into a series of overlapping subsystems by overlapping decentralized control strategy. The feedback gain matrixes of each subsystem can be obtained by using H∞ control algorithm to calculate each subsystem. The vibration control of a twenty layers’ antiseismic steel structure Benchmark model was analyzed with the numerical method. The results show that the proposed method can be applied to control system with time delay. The overlapping decentralized control strategies acquire the similar control effects with that of the centralized control strategy. Moreover, the flexibility of the controller design has been enhanced by using overlapping decentralized control strategies.

scholarly journals QHAR: Q-Holonic-Based ARchitecture for Self-Configuration of Cyber–Physical Production Systems

2021 ◽  
Vol 11 (19) ◽  
pp. 9013
Author(s):  
Douha Macherki ◽  
Thierno M. L. Diallo ◽  
Jean-Yves Choley ◽  
Amir Guizani ◽  
Maher Barkallah ◽  
...  
Keyword(s):  
Decentralized Control ◽  
System Performance ◽  
Production Systems ◽  
Control Level ◽  
Centralized Control ◽  
Four Dimensions ◽  
Potential Capacity ◽  
Heterarchical Control ◽  
Cyber Physical Production Systems

Production systems must be able to adapt to increasingly frequent internal and external changes. Cyber-Physical Production Systems (CPPS), thanks to their potential capacity for self-reconfiguration, can cope with this need for adaptation. To implement the self-reconfiguration functionality in economical and safe conditions, CPPS must have appropriate tools and contextualized information. This information can be organized in the form of an architecture. In this paper, after the analysis of several holonic and nonholonic architectures, we propose a holonic architecture that allows for reliable and efficient reconfiguration. We call this architecture QHAR (Q-Holonic-based ARchitecture). QHAR is constructed based on the idea of a Q-holon, which has four dimensions (physical, cyber, human, and energy) and can exchange three flows (energy, data, and materials). It is a generic Holon that can represent any entity or actor of the supply chain. The QHAR is structured in three levels: centralized control level, decentralized control level, and execution level. QHAR implements the principle of an oligarchical control architecture by deploying both hierarchical and heterarchical control approaches. This ensures the overall system performance and reactivity to hazards. The proposed architecture is tested and validated on a case study.

scholarly journals Analyses of the Control System Strategies and Methodology for Part Power Control of the Simple and Intercooled Recuperated Brayton Helium Gas Turbine Cycles for Generation IV Nuclear Power Plants

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
A. Gad-Briggs ◽  
P. Pilidis ◽  
T. Nikolaidis
Keyword(s):  
Control System ◽  
Inventory Control ◽  
Nuclear Power ◽  
Power Plants ◽  
Control Method ◽  
Control Strategies ◽  
Limiting Factors ◽  
Cycle Performance ◽  
Study Results ◽  
And Performance

An important requirement for Generation IV Nuclear Power Plant (NPP) design is the control system, which enables part power operability. The choices of control system methods must ensure variation of load without severe drawbacks on cycle performance. The objective of this study is to assess the control of the NPP under part power operations. The cycles of interest are the simple cycle recuperated (SCR) and the intercooled cycle recuperated (ICR). Control strategies are proposed for NPPs but the focus is on the strategies that result in part power operation using the inventory control method. First, results explaining the performance and load limiting factors of the inventory control method are documented; subsequently, the transient part power performances are also documented. The load versus efficiency curves were also derived from varying the load to understand the efficiency penalties. This is carried out using a modeling and performance simulation tool designed for this study. Results show that the ICR takes ∼102% longer than the SCR to reduce the load to 50% in design point (DP) performance conditions for similar valve flows, which correlates with the volumetric increase for the ICR inventory tank. The efficiency penalties are comparable for both cycles at 50% part power, whereby a 22% drop in cycle efficiency was observed and indicates limiting time at very low part power. The analyses intend to aid the development of cycles for Generation IV NPPs specifically gas cooled fast reactors (GFRs) and very high-temperature reactors (VHTRs), where helium is the coolant.

Pure Time Delay Analysis for Decentralized Networked Control Systems

2014 ◽  
Author(s):  
Ahmad F. Taha ◽  
Ahmed Elmahdi ◽  
Jitesh H. Panchal ◽  
Dengfeng Sun
Keyword(s):  
Control System ◽  
Time Delay ◽  
Control Systems ◽  
Decentralized Control ◽  
Control Method ◽  
Networked Control System ◽  
Networked Control ◽  
Space Representation ◽  
Global Dynamics ◽  
Pure Time Delay

The network disturbance effect can be considered as either a perturbation or as a pure time delay for the exchanged signals. The network-induced time delay is one of the main challenges when a network is inserted in the feedback loops of a control system. In this paper, our objective is to improve the behavior of a Networked Control System (NCS) by analyzing the time-delay given that the decentralized control design method is adopted. First, we review an observer-based control method for decentralized control systems. Second, we establish a map between the decentralized non-networked system, and the typical NCS state-space representation. The main idea the mapping is to put the Decentralized Networked Control System (DNCS) in a general form and then map the resulting system to the typical NCS form. Third, we derive the global dynamics of the DNCS. Fourth, an upper bound for the time-delay is derived that guarantees the stability of LTI DNCSs. Finally, we present a numerical example that illustrates the applicability of the derived bound.

scholarly journals Design of Centralized PI Control System for Two Variable Processes based on Root Locus Technique

2019 ◽  
Vol 9 (1) ◽  
pp. 4851-4855
Keyword(s):  
Control System ◽  
System Design ◽  
Decentralized Control ◽  
Pi Control ◽  
Control System Design ◽  
Centralized Control ◽  
Single Variable ◽  
Root Locus ◽  
Input And Output ◽  
Simulation Results

This paper describes the design of centralized controller for two variable processes. The two variable process structures are somehow different from the single variable processes. This difference is occurred because of interrelations between the variables present in the process. Hence, when a controller is planned for such systems, the relations amid the variables must be taken into consideration. This process is done in decentralized control system design. But decentralized control system works well when the interrelations between the variables are simple. If the interaction is strong, then the centralized control system is preferred since it uses a controller for each pair of input and output variables. The controller used in main diagonal works for improving the servo performance and off diagonal controller reduces the interrelation effect. So the performance is improved by minimizing the interrelation effects. The design process is easy to understand by field engineers working in industries. The simulation results are included in this paper to specify the efficacy of the proposed scheme.

scholarly journals Design and Analysis of DYC and Torque Vectoring using Multiple-Frequency Control Electronic Differential in an Independent Rear Wheel Driven Electric Vehicle

2019 ◽  
Vol 9 (2) ◽  
pp. 307-315
Keyword(s):  
Control System ◽  
Electric Vehicle ◽  
Control Method ◽  
Sliding Mode ◽  
Control Strategies ◽  
Frequency Control ◽  
Multiple Frequency ◽  
Traction Control ◽  
Traction Control System ◽  
Torque Vectoring

Electric vehicle (EV) are being embraced in recent times as they run on clean fuel, zero tail emission and are environment-friendly. Recent advancements in the field of power electronics and control strategies have made it possible to the advent in the vehicle dynamics, efficiency and range. This paper presents a design for traction control system (TCS) for longitudinal stability and Direct Yaw Control (DYC) for lateral stability simultaneous. The TCS and DYC is based on multiple frequency controlled electronic differential with a simple and effective approach. Along with it, some overviews have been presented on some state of the art in traction control system (TCS) and torque vectoring. The developed technique reduces nonlinearity, multisensory interfacing complexity and response time of the system. This torque and yaw correction strategy can be implemented alongside fuzzy control, sliding mode or neural network based controller. The effectiveness of the control method has been validated using a lightweight neighbourhood electric vehicle as a test platform. The acquired results confirm the versatility of proposed design and can be implemented in any DC motor based TCS/DYC.

Decentralized Control of Structural Acoustic Radiation

2001 ◽  
Author(s):  
Kenneth D. Frampton
Keyword(s):  
Control System ◽  
Decentralized Control ◽  
Large Scale ◽  
Acoustic Radiation ◽  
Electrical Power ◽  
Computational Effort ◽  
Centralized Control ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Recent Developments

Abstract Although the application of active control to vibrations has been investigated from many years, the extension of this technology to large-scale systems has been thwarted, in part, by an overwhelming need for computational effort, data transmission and electrical power. This need has been overwhelming in the sense that the potential applications are unable to bear the power, weight and complex communications requirement of large-scale centralized control systems. Recent developments in MEMS devices and networked embedded devices have changed the focus of such applications from centralized control architectures to decentralized ones. A decentralized control system is one that consists of many autonomous, or semi-autonomous, localized controllers called nodes, acting on a single plant, in order to achieve a global control objective. Each of these nodes has the following capabilities and assets: 1) a relatively limited computational capability including limited memory, 2) oversight of a suite of sensors and actuators and 3) a communications link (either wired or wireless) with neighboring or regional nodes. The objective of a decentralized controller is the same as for a centralized control system: to maintain some desirable global system behavior in the presences of disturbances. However, decentralized controllers do so with each node possessing only a limited amount of information on the global systems response. Exactly what information each node has access to, and how that information is used, is the topic of this investigation.

scholarly journals Analysis on the monitoring system of energy conservation and comfort in office buildings based on internet of things

2020 ◽  
Vol 15 (3) ◽  
pp. 351-355
Author(s):  
Dongmei Li
Keyword(s):  
Energy Efficiency ◽  
Control System ◽  
Internet Of Things ◽  
Energy Saving ◽  
Monitoring System ◽  
Air Conditioning ◽  
Control Method ◽  
Working Hours ◽  
Central Air Conditioning ◽  
Energy Saving Control

Abstract In order to reduce the cost of central air conditioning, we need to reduce its energy consumption. This paper briefly introduced Internet of Things and the energy-saving and comfort monitoring system of central air conditioning based on the Internet of Things. The system took comfort degree as constraint and energy efficiency as objective to control energy saving of central air conditioning. Company X in Guanghan, Sichuan, China, was taken as an example for analysis. The system was compared with the energy-saving control system which took temperature and power as constraints. Compared with before the energy-saving control, the proportion of air conditioning downtime in the working hours of employees increased after the implementation of the two kinds of energy-saving control systems, and the proportion of downtime under the energy-saving control system designed in this study was larger; in addition, after the control of the two kinds of energy-saving systems, the energy efficiency of the air conditioning significantly improved, and the air conditioning under the control of the energy-saving system proposed in this study had more improvement in energy efficiency and higher energy-saving efficiency. The energy-saving control method proposed in this study can effectively reduce the power consumption of the central air conditioning in the office.

Study on Narrow-Gauge Traction Locomotive Control System

2011 ◽  
Vol 418-420 ◽  
pp. 2074-2077
Author(s):  
Jian Zong ◽  
Yi Ruan ◽  
Ming Hui Chen ◽  
Li Bo Xu
Keyword(s):  
Control System ◽  
Power Distribution ◽  
Control Method ◽  
Control Strategies ◽  
Frequency Control ◽  
Good Control ◽  
Drive System ◽  
Motor Drive ◽  
Mechanical Feature ◽  
Motor Drive System

Most narrow-gauge vehicles driven by DC motor now, as DC drive due to power constraints and high maintenance costs, most of them will gradually be replaced by AC drives. But VVVF(Variable Voltage Variable Frequency) control method adopt in some running narrow-track traction locomotives, that can reduce over-current with load starting and should be compensated at low frequency. Based on study the Control strategies of narrow-track locomotives, comparing with the characteristics of power distribution of dual-motor drive system. The motor ought to have the same mechanical feature in dual-motor drive system, vector control strategy select in the control system. Experiments prove the system has good performance of stability, reliability, and good control performance, which can meet the narrow-track traction locomotive control requirements.

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