scholarly journals Investigation of Microgrid Hierarchical Control and Structure

2020 ◽  
Vol 75 (1-4) ◽  
pp. 1-8
Author(s):  
Tayebeh Faghihi ◽  
Shahab Sabzi
Keyword(s):  
Literature Review ◽  
Hierarchical Structure ◽  
Control Strategies ◽  
Hierarchical Control ◽  
Electric Utility ◽  
Control Methods ◽  
The Hierarchical Structure ◽  
The Subject ◽  
Microgrid Control ◽  
And Control

This paper offers a literature review on different structures and control strategies of the microgrid. The implementation of a microgrid system provides significant advantages for both electric utility and end-users. Microgrid control is one of the most sophisticated parts of such implementations that must be taken into account before moving to the next steps. The different control objectives and structures of the main grid and microgrid lead to various control methods proposed for microgrids. The hierarchical structure is the most accepted method for microgrid control that has three levels including primary, secondary, and tertiary. The focus of this study will be on the main modes of typical microgrids, types of microgrid and how to control them. The investigation of this paper will give an overview to the readers, and in our next paper, we will focus more deeply on the subject, with a specific concentration on the concept of secondary control and corresponding trending methods.

scholarly journals A Hierarchical Control Methodology for Renewable DC Microgrids Supporting a Variable Communication Network Health

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 418 ◽  
Author(s):  
Muhammad Shahid ◽  
Muhammad Khan ◽  
Jianming Xu ◽  
Khurram Hashmi ◽  
Salman Habib ◽  
...  
Keyword(s):  
Power Flow ◽  
Renewable Energy Sources ◽  
Hierarchical Control ◽  
Network Connectivity ◽  
Voltage Regulation ◽  
Monitoring And Control ◽  
Dc Microgrids ◽  
Communication Links ◽  
Microgrid Control ◽  
And Control

The monitoring and control of renewable energy sources (RESs) based on DC (Direct Current) microgrids (DC MG) are gaining much consideration at this time. In comparison with the isolated individual control of converters in a microgrid, DC microgrids provide better voltage regulation and harmonized energy generation/consumption. To address the inherent vulnerability of communication links, robust methods have been proposed that improve the resilience of communication-based control. However, the failure of the communication links in microgrid control layers remains a considerable issue that may lead to one or more nodes being disconnected and operating as a communication island. Such types of communication islanding may cause the unpredictable behavior of the system and further destabilization may lead to a cascaded failure. This paper proposes a fast algorithm to detect and evaluate network connectivity based on the information stored at every node in the form of a look-up table. The control structure has been modified under communication islanding, and a communication connectivity observer is used at every node to detect and address power flow issues under communication islanding. The proposed method has been verified through mathematical analysis, simulation, and experimental results.

scholarly journals A Comparative Study of Formation Control at the Earth-Moon L₂ Libration Point

2021 ◽  
Author(s):  
Waqas A. Manzoor
Keyword(s):  
Formation Control ◽  
Controller Design ◽  
Libration Point ◽  
Control Strategies ◽  
Control Input ◽  
Control Methods ◽  
Space Applications ◽  
Affine Systems ◽  
The Earth ◽  
And Control

This thesis examines the performance of control methods that fall under the optimal, predictive and adaptive classifications, subjected to sensor/actuator faults, and presents approaches to apply them to non-affine systems utilizing single thruster and solar sail actuator configurations. The system of interest consists of a leader-follower satellite formation near the L2 point of the Earth-Moon system. The control methods studied here include those which are emerging in the space systems literature, and are evaluated in terms of their transient and steady state responses, and control input variation. Numerical simulation of faults affecting both sensor and propulsion actuator systems are conducted, along with an experiment to validate the results in a laboratory environment. The observed behavioral characteristics in the simulations match those demonstrated in the experiment. Alternative representations of dynamics were explored for controller design of non-affine systems. The research presented herein provides support for the usage of the proposed control strategies in future space applications.

scholarly journals A Comparative Study of Formation Control at the Earth-Moon L₂ Libration Point

2021 ◽  
Author(s):  
Waqas A. Manzoor
Keyword(s):  
Formation Control ◽  
Controller Design ◽  
Libration Point ◽  
Control Strategies ◽  
Control Input ◽  
Control Methods ◽  
Space Applications ◽  
Affine Systems ◽  
The Earth ◽  
And Control

This thesis examines the performance of control methods that fall under the optimal, predictive and adaptive classifications, subjected to sensor/actuator faults, and presents approaches to apply them to non-affine systems utilizing single thruster and solar sail actuator configurations. The system of interest consists of a leader-follower satellite formation near the L2 point of the Earth-Moon system. The control methods studied here include those which are emerging in the space systems literature, and are evaluated in terms of their transient and steady state responses, and control input variation. Numerical simulation of faults affecting both sensor and propulsion actuator systems are conducted, along with an experiment to validate the results in a laboratory environment. The observed behavioral characteristics in the simulations match those demonstrated in the experiment. Alternative representations of dynamics were explored for controller design of non-affine systems. The research presented herein provides support for the usage of the proposed control strategies in future space applications.

scholarly journals Tafsir Tematik Manajemen Kesiswaan di Lembaga Pendidikan Islam

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Hindun Maisaroh ◽  
Toriquddin Toriquddin
Keyword(s):  
Literature Review ◽  
Educational Institution ◽  
Islamic Education ◽  
Literature Research ◽  
Student Management ◽  
Library Research ◽  
Qualitative Descriptive ◽  
The Subject ◽  
Descriptive Approach ◽  
And Control

Thematic interpretation (maudhu’i) is a pattern of interpretation by collecting verses of the Koran that have the same goal, meaning they both discuss one topic and arrange them based on the period of the verse down and pay attention to the background of the causes of the descent, then given explanation, description, comments, and points of content of the sentence. The purpose of this literature research is to find out thematic interpretations (maudhu'i) of the subject of the concept of student management in Islamic Education Institutions. In this study, the authors used a qualitative descriptive approach, and the type of research used was library research. The results of the literature review are: Based on the verses that have been described and analyzed, in the field of student management, the thematic interpretations are raised on QS. Al-Kahfi verses 23-24 and 69, QS Al-Hasyr verse 18, QS Az-Zumar verse 29, QS An-Nahl verse 125, and QS Al-Furqan verse 74, provide an explanation and explanation of the meaning of how student management is in perspective Al-Qur'an. Each of which is in the content as described above, namely that every activity to be carried out must be made with good planning, organization, and implementation and control, which in this case is especially in Surah Al-Kahfi verse 69 and Al-Furqan verse. 74 regarding guidance to students, so that students can develop their talents and interests as well as their competencies so that they become dzurriyah which are qurrota a'yun for parents and their second parents, namely the board of teachers in the Islamic educational institution.

Operation of Microgrid and Control Strategies

2019 ◽  
pp. 434-449
Author(s):  
Suma Deepthi Veeraganti ◽  
Ramchandra Nittala
Keyword(s):  
Electric Power ◽  
Rural Areas ◽  
Control Strategies ◽  
Electric Power Industry ◽  
Power Industry ◽  
Current Control ◽  
Frequency Regulation ◽  
Control Methods ◽  
Islanded Mode ◽  
And Control

Microgrids are the most innovative area in the electric power industry today. A microgrid can operate in grid-connected or islanded mode. In islanded mode, microgrids can provide electricity to the rural areas with lower cost and minimum power losses. Several methods have been proposed in the literature for the successful operation of a microgrid. This chapter presents an overview of the major challenges and their possible solutions for planning, operation, and control of islanded operation of a microgrid. Microgrids are the most innovative area in the electric power industry today. Moreover, microgrids provide local voltage and frequency regulation support and improve reliability and power capacity of the grid. The most popular among the control strategies based on droop characteristics, in addition a central controller is described within a hierarchical control scheme to optimize the operation of the microgrid during interconnected operation. Microgrid control methods, including PQ control, droop control, voltage/frequency control, and current control methods are formulated.

Operation of Microgrid and Control Strategies

2022 ◽  
pp. 111-126
Author(s):  
Suma Deepthi Veeraganti ◽  
Ramchandra Nittala
Keyword(s):  
Electric Power ◽  
Rural Areas ◽  
Control Strategies ◽  
Electric Power Industry ◽  
Power Industry ◽  
Current Control ◽  
Frequency Regulation ◽  
Control Methods ◽  
Islanded Mode ◽  
And Control

Microgrids are the most innovative area in the electric power industry today. A microgrid can operate in grid-connected or islanded mode. In islanded mode, microgrids can provide electricity to the rural areas with lower cost and minimum power losses. Several methods have been proposed in the literature for the successful operation of a microgrid. This chapter presents an overview of the major challenges and their possible solutions for planning, operation, and control of islanded operation of a microgrid. Microgrids are the most innovative area in the electric power industry today. Moreover, microgrids provide local voltage and frequency regulation support and improve reliability and power capacity of the grid. The most popular among the control strategies based on droop characteristics, in addition a central controller is described within a hierarchical control scheme to optimize the operation of the microgrid during interconnected operation. Microgrid control methods, including PQ control, droop control, voltage/frequency control, and current control methods are formulated.

The Coordinated Control Strategies of Voltage Stability Based on Expert Rules

2013 ◽  
Vol 732-733 ◽  
pp. 772-777
Author(s):  
Fei Zhang ◽  
Chun Lin Guo ◽  
Ling Yun Jiang ◽  
Lin Yang ◽  
Jian Zhang
Keyword(s):  
Voltage Stability ◽  
Control Strategies ◽  
Coordinated Control ◽  
Control Methods ◽  
Stability Problems ◽  
Process Characteristics ◽  
Control Rules ◽  
Facts Devices ◽  
And Control ◽  
Better Than

According to the process characteristics and control methods of different voltage stability problems, the paper researches control rules and strategies of the voltage stability, then sets up controllers of FACTS devices on a simulation platform, and puts forward the coordinated control strategies of voltage stability problems based on expert rules. The simulation studies have shown that control effects of multiple FACTS devices are significantly better than a single device, and the coordinated control methods based on the expert rules is more conducive to improving voltage stability.

scholarly journals A Comprehensive Motivation of Multilayer Control Levels for Microgrids: Synchronization, Voltage and Frequency Restoration Perspective

2020 ◽  
Vol 10 (23) ◽  
pp. 8355
Author(s):  
Ronald Jackson ◽  
Shamsul Aizam Zulkifli ◽  
Mohamed Benbouzid ◽  
Suriana Salimin ◽  
Mubashir Hayat Khan ◽  
...  
Keyword(s):  
Control Method ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Hierarchical Control ◽  
Control Level ◽  
Point Of View ◽  
Power Sharing ◽  
Grid Synchronization ◽  
Future Prediction ◽  
And Control

The current paradigm in integrating intermittent renewable energy sources into microgrids presents various technical challenges in terms of reliable operation and control. This paper performs a comprehensive justification of microgrid trends in dominant control strategies. It covers multilayer hierarchical control schemes, which are able to integrate seamlessly with coordinated control strategies. A general overview of the hierarchical control family that includes primary, secondary, tertiary controls is presented. For power sharing accuracy and capability, droop and non-droop-based controllers are comprehensively studied to address further development. The voltage and frequency restoration techniques are discussed thoroughly based on centralized and decentralized method in order to highlights the differences for better comprehend. The comprehensive studies of grid synchronization strategies also overviewed and analyzed under balanced and unbalanced grid conditions. The details studies for each control level are displayed to highlight the benefits and shortcomings of each control method. A future prediction from the authors’ point of view is also provided to acknowledge which control is adequate to be adopted in proportion to their products applications and a possibility technique for self-synchronization is given in this paper.

scholarly journals Evaluation of Motor Primitive-Based Adaptive Control for Lower Limb Exoskeletons

2020 ◽  
Vol 7 ◽  
Author(s):  
Polyana F. Nunes ◽  
Icaro Ostan ◽  
Adriano A. G. Siqueira
Keyword(s):  
Knee Joint ◽  
Control Strategies ◽  
Lower Limbs ◽  
Motor Primitives ◽  
Motor Primitive ◽  
Gait Characteristics ◽  
Limited Effectiveness ◽  
Generalized Momentum ◽  
The Subject ◽  
And Control

In order to assist after-stroke individuals to rehabilitate their movements, research centers have developed lower limbs exoskeletons and control strategies for them. Robot-assisted therapy can help not only by providing support, accuracy, and precision while performing exercises, but also by being able to adapt to different patient needs, according to their impairments. As a consequence, different control strategies have been employed and evaluated, although with limited effectiveness. This work presents a bio-inspired controller, based on the concept of motor primitives. The proposed approach was evaluated on a lower limbs exoskeleton, in which the knee joint was driven by a series elastic actuator. First, to extract the motor primitives, the user torques were estimated by means of a generalized momentum-based disturbance observer combined with an extended Kalman filter. These data were provided to the control algorithm, which, at every swing phase, assisted the subject to perform the desired movement, based on the analysis of his previous step. Tests are performed in order to evaluate the controller performance for a subject walking actively, passively, and at a combination of these two conditions. Results suggest that the robot assistance is capable of compensating the motor primitive weight deficiency when the subject exerts less torque than expected. Furthermore, though only the knee joint was actuated, the motor primitive weights with respect to the hip joint were influenced by the robot torque applied at the knee. The robot also generated torque to compensate for eventual asynchronous movements of the subject, and adapted to a change in the gait characteristics within three to four steps.

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