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CEP special issue on smart power system control
Control Engineering Practice ∎ (∎∎∎∎) ∎∎∎–∎∎∎
Contents lists available at ScienceDirect
Control Engineering Practice journal homepage: www.elsevier.com/locate/conengprac
Editorial
CEP special issue on smart power system control
The term “Smart Grid” in a broader sense implies no less than the fundamental transformation of the electric power system. Many of the issues investigated and the solutions proposed in this context ultimately come down to control applications. As is wellknown, the power system represents the largest and most complex dynamic system. It goes without saying that its reliable and stable operation is of fundamental importance for the well-being of the modern society, and smart grid applications promise to add a new layer to enhance the efficiency and reliability of the system. Although many of the new smart grid approaches and applications involve modern communication and computer technologies, the underlying theoretical backgrounds are often not completely new. But usually new aspects, ideas and modifications emerge in the process of application to power systems. In this regard the power system also proves to be an excellent test area where one can assess the practicality of any new theoretical concepts. Smart grid therefore is uniquely positioned to bring power and control engineers together to learn from the experiences and expertize of one another. A second important trend at the moment is the large-scale utilization of renewable energy sources. These plants - compared with the traditional generation units - are small, and exist in large numbers spread throughout the network. To ensure the controllability and observability of the system they need to be integrated into a wide area communication network. The communication and control tasks, including reliability and cybersecurity aspects, are so broad that they extend beyond the purview of power engineers. Interdisciplinarity is an absolute requirement where control engineering has to play a central role. The Technical Committee 6.3 on Power and Energy Systems of the IFAC has taken up the new challenges and has intensified its activities in recent years considerably. As a result, a large number of invited sessions of TC 6.3 were devoted to the subject of Smart Grid in the IFAC World Congress 2014 in Cape Town. Also, in terms of the number of contributions, the TC was a leader compared to the other TC. The special issue at hand includes selected contributions from the IFAC World Congress in Cape Town. In accordance with the rules of the CEP, the authors of the tentatively selected best papers were asked to revise the contents or to add new results to become eligible for a new publication in the journal CEP. The present selection does not cover the complete cross-section of the very extensive and varied activities in the field of smart grid. In addition, the focus is on control and system theoretical approaches. Seven papers are included in this special issue: Two of the papers deal with model predictive control (MPC), but
http://dx.doi.org/10.1016/j.conengprac.2016.03.011 0967-0661/& 2016 Elsevier Ltd. All rights reserved.
the approaches used are quite different. The first paper proposes a method for efficient building temperature control, whereby the focus is on finding a suitable tradeoff between the linear and nonlinear MPC. The approach is interesting and practice-oriented. The second MPC article deals with the load - frequency control taking into account imbalance uncertainties arising from wind generation. Stability has always been a topic of great interest in power system research. Three papers deal with this topic. One of the papers proposes a fault-tolerant emergency control, whereby the oscillatory stability is to be improved through adaptation to the changed situation. For this purpose, a central reconfiguration block is proposed and designed. Stability monitoring is the topic of another article. For this purpose, a synchrophasor based system for power system observability and dynamic state estimation is proposed. In the third article, the authors discuss the characterization of power systems near their stability boundaries using the sub-Gramian method. Microgrids represent decentralized small energy systems where the control tasks both in the island and in mains parallel operation pose a particular challenge. This issue is the topic in one of the papers. As generation units photovoltaic and fuel cells are considered. For the tuning of the proposed controller a heuristic optimization method is used. Conventional power plants based on steam turbines are likely to be around for a while. In this technology, the focus is mainly about process improvements and efficiency enhancement. However, with this the control task is getting ever more complex and challenging. The last article deals with an intelligent coordinated controller design for a 600 MW supercritical boiler by utilizing a neural network based approach. The papers presented in this special issue represent only a small selection of power system control applications. Research in the field of smart grid is continuing and even growing. It is currently the foremost power system research area. Interested researchers in different disciplines are encouraged to come up with new ideas, applications, test results and publish their results in CEP.
István Erlich University of Duisburg, Essen, Institute of Electrical Power Systems, Chair of IFAC TC 6.3 on Power and Energy Systems, Germany E-mail address: [email protected]
Contents lists available at ScienceDirect
Control Engineering Practice journal homepage: www.elsevier.com/locate/conengprac
Editorial
CEP special issue on smart power system control
The term “Smart Grid” in a broader sense implies no less than the fundamental transformation of the electric power system. Many of the issues investigated and the solutions proposed in this context ultimately come down to control applications. As is wellknown, the power system represents the largest and most complex dynamic system. It goes without saying that its reliable and stable operation is of fundamental importance for the well-being of the modern society, and smart grid applications promise to add a new layer to enhance the efficiency and reliability of the system. Although many of the new smart grid approaches and applications involve modern communication and computer technologies, the underlying theoretical backgrounds are often not completely new. But usually new aspects, ideas and modifications emerge in the process of application to power systems. In this regard the power system also proves to be an excellent test area where one can assess the practicality of any new theoretical concepts. Smart grid therefore is uniquely positioned to bring power and control engineers together to learn from the experiences and expertize of one another. A second important trend at the moment is the large-scale utilization of renewable energy sources. These plants - compared with the traditional generation units - are small, and exist in large numbers spread throughout the network. To ensure the controllability and observability of the system they need to be integrated into a wide area communication network. The communication and control tasks, including reliability and cybersecurity aspects, are so broad that they extend beyond the purview of power engineers. Interdisciplinarity is an absolute requirement where control engineering has to play a central role. The Technical Committee 6.3 on Power and Energy Systems of the IFAC has taken up the new challenges and has intensified its activities in recent years considerably. As a result, a large number of invited sessions of TC 6.3 were devoted to the subject of Smart Grid in the IFAC World Congress 2014 in Cape Town. Also, in terms of the number of contributions, the TC was a leader compared to the other TC. The special issue at hand includes selected contributions from the IFAC World Congress in Cape Town. In accordance with the rules of the CEP, the authors of the tentatively selected best papers were asked to revise the contents or to add new results to become eligible for a new publication in the journal CEP. The present selection does not cover the complete cross-section of the very extensive and varied activities in the field of smart grid. In addition, the focus is on control and system theoretical approaches. Seven papers are included in this special issue: Two of the papers deal with model predictive control (MPC), but
http://dx.doi.org/10.1016/j.conengprac.2016.03.011 0967-0661/& 2016 Elsevier Ltd. All rights reserved.
the approaches used are quite different. The first paper proposes a method for efficient building temperature control, whereby the focus is on finding a suitable tradeoff between the linear and nonlinear MPC. The approach is interesting and practice-oriented. The second MPC article deals with the load - frequency control taking into account imbalance uncertainties arising from wind generation. Stability has always been a topic of great interest in power system research. Three papers deal with this topic. One of the papers proposes a fault-tolerant emergency control, whereby the oscillatory stability is to be improved through adaptation to the changed situation. For this purpose, a central reconfiguration block is proposed and designed. Stability monitoring is the topic of another article. For this purpose, a synchrophasor based system for power system observability and dynamic state estimation is proposed. In the third article, the authors discuss the characterization of power systems near their stability boundaries using the sub-Gramian method. Microgrids represent decentralized small energy systems where the control tasks both in the island and in mains parallel operation pose a particular challenge. This issue is the topic in one of the papers. As generation units photovoltaic and fuel cells are considered. For the tuning of the proposed controller a heuristic optimization method is used. Conventional power plants based on steam turbines are likely to be around for a while. In this technology, the focus is mainly about process improvements and efficiency enhancement. However, with this the control task is getting ever more complex and challenging. The last article deals with an intelligent coordinated controller design for a 600 MW supercritical boiler by utilizing a neural network based approach. The papers presented in this special issue represent only a small selection of power system control applications. Research in the field of smart grid is continuing and even growing. It is currently the foremost power system research area. Interested researchers in different disciplines are encouraged to come up with new ideas, applications, test results and publish their results in CEP.
István Erlich University of Duisburg, Essen, Institute of Electrical Power Systems, Chair of IFAC TC 6.3 on Power and Energy Systems, Germany E-mail address: [email protected]