Adaptive fuzzy control for power-frequency characteristic regulation in high-RES power systems

Future power systems control will require large-scale activation of reserves at distribution level. Despite their high potential, distributed energy resources (DER) used for frequency control pose challenges due to unpredictability, grid bottlenecks, etc. To deal with these issues, this study presents a novel strategy of power frequency characteristic dynamic adjustment based on the imbalance state. This way, the concerned operators become aware of the imbalance location but also a more accurate redistribution of responsibilities in terms of reserves activations is achieved. The proposed control is based on the concept of “cells” which are power systems with operating capabilities and responsibilities similar to control areas (CAs), but fostering the use of resources at all voltage levels, particularly distribution grids. Control autonomy of cells allows increased RES hosting. In this study, the power frequency characteristic of a cell is adjusted in real time by means of a fuzzy controller, which curtails part of the reserves, in order to avoid unnecessary deployment throughout a synchronous area, leading to a more localised activation and reducing losses, congestions and reserves exhaustion. Simulation tests in a four-cell reference power system prove that the controller significantly reduces the use of reserves without compromising the overall stability

Implementation of fuzzy logic for mitigating conflicts of frequency containment

Ever increasing shares of intermittent RES in present and future power systems pose new challenges with regard to operation, particularly balance, frequency and voltage stability. Towards effective solutions, the ELECTRA IRP project has developed a novel structure for future power systems operation, by dividing them in a number of Cells, constituting so a Web-of-Cells, and equipped with controllers addressing operation objectives. This paper deals with the Frequency Containment Control use case and, in particular, its implementation in the context of operation constraints imposed by different system conditions. To this end, a design method based on fuzzy logic for avoiding conflicts caused from these conditions or multiple control loops implemented on the same resource is proposed. Simulation results for various selected scenarios and controllers show the effectiveness of the proposed approach

Frequency restoration reserves : provision and activation using a multi-agent demand control system

In this work a control system for restoration reserve providers is proposed in which optimal biddings of restoration reserve capacity are made based on the predicted flexibility of the reserve resources within the portfolio of the reserve provider. I t is assumed that the gate closure time for submitting reserve capacit y bids is 1 hour before activation time. The reserve capacity bids need to be formed so that activation of the capacity is always feasible, irrespective of the consumption of the portfolio before an activation request. The determination of the optimal reserve capacity bids is only based on aggregated flexibility constraint information received by the individual flexible resources within the portfolio of the reserve provider. No further resource-spe cific information is used to determine the optimal reserve capacity bid. The activation and dispatch of the required power consumption at real time is done through a market-based multi-agent control system. A simulation example, in which the reserve capacity of a portfolio of batteries is simulated, proves the feasibility of the proposed approach and shows that a high precision of the portfolio response can be obtained

Integrating plus energy buildings and districts with the eu energy community framework:Regulatory opportunities, barriers and technological solutions

The aim of this paper is to assess opportunities the Clean Energy Package provides for Plus Energy Buildings (PEBs) and Plus Energy Districts (PEDs) regarding their economic optimization and market integration, possibly leading to new use cases and revenue streams. At the same time, insights into regulatory limitations at the national level in transposing the set of EU Clean Energy Package provisions are shown. The paper illustrates that the concepts of PEBs and PEDs are in principle compatible with the EU energy community concepts, as they relate to technical characteristics while energy communities provide a legal and regulatory framework for the organization and governance of a community, at the same time providing new regulatory space for specific activities and market integration. To realize new use cases, innovative ICT approaches are needed for a range of actors actively involved in creating and operating energy communities as presented in the paper. The paper discusses a range of different options to realize PEBs and PEDs as energy communities based on the H2020 EXCESS project. It concludes, however, that currently the transposition of the Clean Energy Package by the EU Member States is incomplete and limiting and as a consequence, in the short term, the full potential of PEBs and PEDs cannot be exploited

PDG: A Process-Level Debugger in GRAPE for communicating processes on transputer platforms

. In this paper, we describe the process-level debugger of GRAPE, a hierarchical graphical programming environment for concurrent programs. This debugger allows to debug concurrent programs that are based on communicating sequential processes. Its unique feature is that it clearly separates the identification of erroneous processes from the exact localisation of the bug on the source-level. This divide-and-conquer approach is absolutely necessary for debugging complex parallel programs in a fast and systematic way. Our process-level debugging approach is based on an animation of program behaviour on its hierarchical graphical representation. Graphical views are used that reflect the programmer's mental picture of the application. Hierarchy allows us to employ a top-down debugging approach in which we successively refine the search-space by zooming in on suspect processes first-timeright. During animation, a debugging kernel implementing a record-replay mechanism guarantees reproducible..

Powerful High-Level Debugger for Parallel Programs

The testing and debugging of complex programs has always been one of the most cost-determining factors in software design. This is even more true when parallel programs are considered. Debugging them is often based on a debugging cycle. First we make an assumption about the probable source of the bug, and next the validity of this assumption is verified. By repeatedly applying this technique, we try to limit the search-space until eventually the bug is resolved. There is a great need however for powerful high-level tools that enable the localization of bugs without indulging in this time-consuming error-prone debugging cycle. This paper describes such a high-level debugging tool, based on the animation of a program on its hierarchical-graphical representation. Keywords : Parallel programs, high-level debugging, animation, graphical programming environment 1. INTRODUCTION As computer hardware is getting less expensive every day, not longer the hardware cost, but the cost of the people ..

Architectures and concepts for smart decentralised energy systems

Publisher Copyright: © 2021 Elsevier Inc. All rights reserved.The idea of creation of more decentralized power system has been circulating for a while, but started to materialise only during the recent years, when massive introduction of support schemes for RES has started to move more and more generation into the distribution network. Apart from the environmental benefits, this has created several challenges for planning and operation of the conventional power system. Furthermore, the growing recognition of necessity for optimization across different energy carriers for example “ETIP SNET Vision 2050" is also pointing towards more and more decentralized system. This chapter presents an overview of the main architectures and concepts for smart decentralized energy systems, through the critical analysis of recent documents such as Pan-European roadmaps (ETIP-SNET) and scenarios (TYNDP2020), results of R&D projects and regulatory documents (“Clean Energy for all Europeans”). The chapter is organized in four parts and starts with background for decentralization: driving forces, trends, and foreseen benefits as well as potential challenges and pitfalls. The second section starts with an overview of different levels of decentralization. The decentralized architecture combined with new ICT infrastructure (including machine learning), opens possibility for new and more efficient control approaches (balancing and voltage). This issue has been studied for example in ELECTRA IRP project, elaborating a cellular structure with dedicated set of novel controls for the power system. This section will further look at the market alternatives and the areas with several unresolved issues and gaps, which must be explored further and require an immediate attention from the research community. The following section will present views of several key stakeholders on decentralization of the power system. It appears that transformation to partially or fully decentralized power system will require certain changes of the present and creation of new roles and responsibilities among actors on the power market. Some of these modifications has been already introduced and formalised in the most recent recast of “Clean Energy for all Europeans.” The section will further present somewhat different opinions about this among the involved stakeholders, which have been expressed in several position papers. The final section makes conclusions and links the content to other chapters of the book.Peer reviewe