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 From Hierarchical Control to Flexible Interactive Electricity Services: A Path to Decarbonization

2021 ◽  
Vol 15 ◽  
pp. 1558-1570
Author(s):  
Marija D. Ilic ◽  
Pedro M. S. Carvalho
Keyword(s):  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Hierarchical Control ◽  
Electric Energy ◽  
Specific Model ◽  
Net Energy ◽  
Primary Control ◽  
Interaction Variables ◽  
And Control

We propose to conceptualise electric energy systems as complex dynamical systems using physically intuitive multilayered energy modelling as the basis for systematic diverse technology integration, and control in on-line operations. It is shown that such modelling exhibits unique structure which comes from the conservation of instantaneous power (P) and of instantaneous reactive power ( _Q), (interaction variables (intVar)) at the interfaces of subsystems. The intVars are used as a means to model and control the interactive zoomed-out inter-modular (inter-area, inter-component) system dynamics. Control co-design can then be pursued using these models so that the primary control shapes intVars of its own module by using its own lowlevel detailed technology-specific model and intVar info exchange with the neighbours. As a result, we describe how the proposed approach can be used to support orderly evolution from today’s hierarchical control to a platform enabling flexible interactive protocols for electricity services. The potential for practical use of the proposed concepts is far-reaching and transparent. All that needs to be conceived is that intVar characterising any intelligent Balancing Authority (iBA) is a generalisation of today’s Area Control Error (ACE) characterising net energy balance of a Balancing Authority (BA). An iBA can be any subsystem with its own sub-objectives, such as distributed energy resources (DERs) comprising customers and grid forming microgrids; distribution systems; transmission systems; Independent System Operators (ISOs); and, ultimately, electric energy markets within large interconnection. Several industry problems are described as particular sub-problems of general interactive electricity services. These formulations help one compare models and assumptions used as part of current solutions, and propose enhanced solutions. Most generally, feasibility and stability conditions can be introduced for ensuring feasible power flow solutions, regulated frequency and voltage and orderly power exchange across the iBAs.

Approach to Nav Aids System on Islands

2021 ◽  
Author(s):  
Khalil Ibrahim Alblooshi ◽  
Kamaljit Singh ◽  
Raju Paul ◽  
Faris Ragheb Kamal
Keyword(s):  
International Association ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Storm Events ◽  
Effective Solution ◽  
Monitoring And Control ◽  
Monitoring And Control System ◽  
Navigational Aids ◽  
Maintenance Requirements ◽  
And Control

Abstract Offshore business is gradually moving from traditional Well Head Platforms to the concept of Artificial Drill Islands and use of renewable energy sources. Navigational Aids design for artificial drilling islands has unique challenges due to vast periphery. This paper highlights all such challenges along with recommendations for a reliable and cost effective solution. Clients as well as FEED/EPC Contractors can benefit from the experience shared in this paper. The trend over the last decade has been to develop Navigation Aids that minimize maintenance requirements whilst maintaining stable and satisfactory performance. Although, Navigation Aids are automated there is still a need for regular visual inspections as there is always the risk of vandalism, ship impact or damage during significant storm events. Navigational Aids System shall be in strict compliance with International Association of Lighthouse Authorities (IALA) Guidelines. In addition to usual Visual & Audible Navigations Aids, artificial islands require break water lanterns (both red & green type). Also, number of Navigational Aids is much more than those required for a typical offshore platform. Requirement of interfaces with remote ends need to be clearly defined as these have impact on the design and ultimate cost. GSM monitoring and control system, GPS synchronization & AIS remote monitoring shall be considered. Cabling over the Island periphery is neither reliable nor cost effective solution. Standalone solar power based Navigational Aids Skids with all control and monitoring facilities can be more suitable solution. Considering that Island Contractor provides few Navigational Aids before the mobilization of EPC Contractor, it is essential to coordinate the Navigational Aids design aspects to ensure synergy in terms of compatibility.

IoE-Based Control and Monitoring of Electrical Grids

2019 ◽  
pp. 57-82 ◽  
Author(s):  
Nelson Pinto ◽  
Dario Cruz ◽  
Jânio Monteiro ◽  
Cristiano Cabrita ◽  
Jorge Semião ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Energy Management ◽  
Renewable Energy Sources ◽  
Monitoring And Control ◽  
Monitoring And Control System ◽  
Energy Management Systems ◽  
Management Measures ◽  
Electrical Grids ◽  
And Control ◽  
Levels Of Integration

In many countries, renewable energy production already represents an important percentage of the total energy that is generated in electrical grids. In order to reach higher levels of integration, demand side management measures are yet required. In fact, different from the legacy electrical grids, where at any given instant the generation levels are adjusted to meet the demand, when using renewable energy sources, the demand must be adapted in accordance with the generation levels, since these cannot be controlled. In order to alleviate users from the burden of individual control of each appliance, energy management systems (EMSs) have to be developed to both monitor the generation and consumption patterns and to control electrical appliances. In this context, the main contribution of this chapter is to present the implementation of such an IoT-based monitoring and control system for microgrids, capable of supporting the development of an EMS.

scholarly journals A Generalized and Mode-adaptive Approach to the Power Flow Analysis of the Isolated Hybrid AC/DC Microgrids

2019 ◽  
Author(s):  
Yu Xiao ◽  
Chunguang Ren ◽  
Xiaoqing Han ◽  
Peng Wang
Keyword(s):  
High Performance ◽  
Power Flow ◽  
Low Cost ◽  
External Disturbance ◽  
Flow Analysis ◽  
Distributed Energy ◽  
Dc Microgrid ◽  
Dc Microgrids ◽  
Binary Matrices ◽  
And Control

HybridAC/DC microgrids(HMG) are emerging as an attracting method for integrating the AC/DC distributed energy resources(DERs) with the features of high-performance and low-cost. In the isolated hybrid AC/DC microgrid (IHMG), the key problem is how to balance the power variation and regulate the voltage and frequency. Various energy storage systems (ESS)and interlinking converter (IC) technologies are viable for this application. The present study proposes a novel unified power flow model to evaluate and compare the abilities of the ESS with different connection topologies and ICs with different control approaches to maintain the voltage and frequency stability of the IHMG. In order to investigate the performance of the proposed scheme, five operation modes of the IHMG are defined and explained. The classification is based on the connection topologies and control modes of the ESS/IC in the IHMG. Then, a set of generic PF equations are derived. Moreover, three binary matrices are applied in the construction of the unified power equations. These matrices are used for describing the running state of the IHMG. Finally, in order to verify the proposed scheme, it is applied to several case studies of the IHMG. The operation characteristics of multi-DC subgrids IHMG in different modes, particularly when an external disturbance occurs, are investigated.

scholarly journals Optimized Hierarchical Control for an AC Microgrid Under Attack

Ingeniería ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 64-82
Author(s):  
Vladimir Toro ◽  
Eder David Baron ◽  
Eduardo Mojica-Nava
Keyword(s):  
Power Flow ◽  
Hierarchical Control ◽  
Active Power ◽  
Cyber Attacks ◽  
Cyber Attack ◽  
Secondary Control ◽  
Confidence Factor ◽  
Communication Links ◽  
Local Controller ◽  
The Stability

Context: An inverter-based microgrid working in islanded mode can suffer cyber- attacks, these can be done against either the local controller or the communication links among the inverters. Secondary control is able to reject those attacks, however, a tertiary control action is necessary in order to stabilize the power flow among the microgrid. Method: Confidence factor technique allows to reject attacks in a microgrid acting directly over the secondary control, however, this technique omits other factor related to the power available. In this case, secondary control was complemented with a tertiary control that includes optimization criteria. Results: An inverter-based microgrid is simulated in Matlab for different scenarios and under cyberattack, this allows checking the correct response of the controller under attacks and the effective powersharing among inverters. Conclusions: The tertiary control allows stabilizing the active power of the system after the rejection of a cyber-attack by the secondary control. Each inverter supplies active power according to its máximum power rating without affecting the stability of the whole system.

scholarly journals Towards more resilient electrical networks in urban areas

2018 ◽  
Vol 61 ◽  
pp. 00015
Author(s):  
Anna Palau-Mayo ◽  
Mikel de Prada ◽  
José Luís Domínguez-García
Keyword(s):  
Urban Areas ◽  
Power Flow ◽  
Renewable Energy Sources ◽  
Decisive Role ◽  
Extreme Weather Events ◽  
Self Healing ◽  
Electrical Networks ◽  
Distribution Grid ◽  
System Operator ◽  
And Control

The requirement of system decarbonisation fixed by the EU 2050 plan is leading to an increased establishment of renewable energy sources. Additionally, the emergence of power electronics and ICT technologies has played a decisive role towards a novel distribution electric grid allowing new monitoring, operation and control. In parallel to the energetic transition, an increasing occurrence of extreme weather events and a reinforced concern on climate change leads to the concept of resilience, which is the capacity to adapt and recover from disruptive events in a coordinated procedure. After a fault event, assuming the objective of the system operator is to minimize the load unsupplied, the present study aims at outlining an early research state on the concept of self-healing through the development of a power flow optimization algorithm within a meshed network. Moreover, the effects of integrating Distributed Energy Resources (DER) in order to increase distribution grid resilience as well as to ensure and secure power supply to the system leads to the clusterization of the power system. With controllable technologies, the on-outaged areas are able to disconnect from the main grid, creating islanded microgrids (MGs) which can work autonomously and consequently, increase grid resilience.

IoT-CAN based system for remote monitoring and control of DC microgrids

2021 ◽  
Author(s):  
Alejandro Jose Ortiz-Larquin ◽  
Javier Diaz-Carmona ◽  
Elias Rodriguez-Segura ◽  
Alejandro Espinosa-Calderon ◽  
Juan Prado-Olivarez ◽  
...  
Keyword(s):  
Remote Monitoring ◽  
Monitoring And Control ◽  
Dc Microgrids ◽  
Remote Monitoring And Control ◽  
And Control

Kubik: Open Building Approach For The Construction of an Unique Experimental Facility Aimed to Improve Energy Efficiency in Buildings

2011 ◽  
Vol 36 (1) ◽  
pp. 63-72 ◽  
Author(s):  
José A. Chica ◽  
Inés Apraiz ◽  
Peru Elguezabal ◽  
Marc O. Rrips ◽  
Victor Sánchez ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Renewable Energy Sources ◽  
Indoor Environments ◽  
Monitoring And Control ◽  
Monitoring And Control System ◽  
Improve Energy Efficiency ◽  
New Concepts ◽  
Lighting Systems ◽  
And Control

KUBIK is aimed to the development of new concepts, products and services to improve the energy efficiency of buildings. The main characteristic of KUBIK is the capability to built realistic scenarios to analyse the energy efficiency obtained from the holistic interaction of the constructive solution for the envelope, the intelligent management of the climatisation and lighting systems and the supply from renewable energy sources. The R&D infrastructure consists of a building able to provide up to 500 m2 distributed in an underground floor, a ground floor and up to two storeys; the main dimensions are 10,00 m. width x 10,00 m. length x 10,00 meter high (plus and underground floor 3,00 m. depth). The supply of energy is based on the combination of conventional and renewable energy (geothermic, solar and wind). In addition, the building is equipped with a monitoring and control system which provides the necessary information for the R&D activities. KUBIK's main structure provides an experimental, adaptable and reconfigurable infrastructure to create the indoor environments to analyse and to allow the assembly of the constructive solutions for the envelope, floors and partitions which performance must to be assessed under realistic conditions.

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