Large-Scale System Analysis Under Uncertainty

2022 ◽  
Author(s):  
Alejandro D. Domínguez-García

Discover a comprehensive set of tools and techniques for analyzing the impact of uncertainty on large-scale engineered systems. Providing accessible yet rigorous coverage, it showcases the theory through detailed case studies drawn from electric power application problems, including the impact of integration of renewable-based power generation in bulk power systems, the impact of corrupted measurement and communication devices in microgrid closed-loop controls, and the impact of components failures on the reliability of power supply systems. The case studies also serve as a guide on how to tackle similar problems that appear in other engineering application domains, including automotive and aerospace engineering. This is essential reading for academic researchers and graduate students in power systems engineering, and dynamic systems and control engineering.

Author(s):  
Sheree A Pagsuyoin ◽  
Joost R Santos

Water is a critical natural resource that sustains the productivity of many economic sectors, whether directly or indirectly. Climate change alongside rapid growth and development are a threat to water sustainability and regional productivity. In this paper, we develop an extension to the economic input-output model to assess the impact of water supply disruptions to regional economies. The model utilizes the inoperability variable, which measures the extent to which an infrastructure system or economic sector is unable to deliver its intended output. While the inoperability concept has been utilized in previous applications, this paper offers extensions that capture the time-varying nature of inoperability as the sectors recover from a disruptive event, such as drought. The model extension is capable of inserting inoperability adjustments within the drought timeline to capture time-varying likelihoods and severities, as well as the dependencies of various economic sectors on water. The model was applied to case studies of severe drought in two regions: (1) the state of Massachusetts (MA) and (2) the US National Capital Region (NCR). These regions were selected to contrast drought resilience between a mixed urban–rural region (MA) and a highly urban region (NCR). These regions also have comparable overall gross domestic products despite significant differences in the distribution and share of the economic sectors comprising each region. The results of the case studies indicate that in both regions, the utility and real estate sectors suffer the largest economic loss; nonetheless, results also identify region-specific sectors that incur significant losses. For the NCR, three sectors in the top 10 ranking of highest economic losses are government-related, whereas in the MA, four sectors in the top 10 are manufacturing sectors. Furthermore, the accommodation sector has also been included in the NCR case intuitively because of the high concentration of museums and famous landmarks. In contrast, the Wholesale Trade sector was among the sectors with the highest economic losses in the MA case study because of its large geographic size conducive for warehouses used as nodes for large-scale supply chain networks. Future modeling extensions could potentially include analysis of water demand and supply management strategies that can enhance regional resilience against droughts. Other regional case studies can also be pursued in future efforts to analyze various categories of drought severity beyond the case studies featured in this paper.


Author(s):  
Ken P. Games ◽  
David I. Gordon

ABSTRACTSand waves are well known indicators of a mobile seabed. What do we expect of these features in terms of migration rates and seabed scour? We discuss these effects on seabed structures, both for the Oil and Gas and the Windfarm Industries, and consider how these impact on turbines and buried cables. Two case studies are presented. The first concerns a windfarm with a five-year gap between the planning survey and a subsequent cable route and environmental assessment survey. This revealed large-scale movements of sand waves, with the displacement of an isolated feature of 155 m in five years. Secondly, another windfarm development involved a re-survey, again over a five-year period, but after the turbines had been installed. This showed movements of sand waves of ∼50 m in five years. Observations of the scour effects on the turbines are discussed. Both sites revealed the presence of barchans. Whilst these have been extensively studied on land, there are few examples of how they behave in the marine environment. The two case studies presented show that mass transport is potentially much greater than expected and that this has implications for choosing turbine locations, the effect of scour, and the impact these sediment movements are likely to have on power cables.


Author(s):  
Farhad Namdari ◽  
Fatemeh Soleimani ◽  
Esmaeel Rokrok

<p><em>Environmental concerns along with the increasing demand on electrical power, have led to power generation of renewable sources like wind. Connecting wind turbines in large scale powers with transmission network makes new challenges like the impact of these renewable sources on power system protection. This paper studies the impact of fault resistance and its location on voltage and current fundamental frequencies of faulted lines connected to DFIG based wind farms and it will be demonstrated that because of the large differences between these frequencies, impedance measuring of distance relays is inefficient. Hence in these power systems using conventional impedance measurements is not suitable anymore and new impedance measuring approaches are required in distance relays.</em></p>


2019 ◽  
Vol 112 ◽  
pp. 02011
Author(s):  
Cristian-Gabriel Alionte ◽  
Daniel-Constantin Comeaga

The importance of renewable energy and especially of eolian systems is growing. For this reason, we propose the investigation of an important pollutant - the noise, which has become so important that European Commission and European Parliament introduced Directive 2002/49/CE relating to the assessment and management of environmental noise. So far, priority has been given to very large-scale systems connected to national energy systems, wind farms whose highly variable output power could be regulated by large power systems. Nowadays, with the development of small storage capacities, it is feasible to install small power wind turbines in cities of up to 10,000 inhabitants too. As a case study, we propose a simulation for a rural locality where individual wind units could be used. This specific case study is interesting because it provides a new perspective of the impact of noise on the quality of life when the use of this type of system is implemented on a large scale. This option, of distributed and small power wind turbine, can be implemented in the future as an alternative or an adding to the common systems.


Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6532
Author(s):  
Vahab Rostampour ◽  
Thom S. Badings ◽  
Jacquelien M. A. Scherpen

We present a Buildings-to-Grid (BtG) integration framework with intermittent wind-power generation and demand flexibility management provided by buildings. First, we extend the existing BtG models by introducing uncertain wind-power generation and reformulating the interactions between the Transmission System Operator (TSO), Distribution System Operators (DSO), and buildings. We then develop a unified BtG control framework to deal with forecast errors in the wind power, by considering ancillary services from both reserves and demand-side flexibility. The resulting framework is formulated as a finite-horizon stochastic model predictive control (MPC) problem, which is generally hard to solve due to the unknown distribution of the wind-power generation. To overcome this limitation, we present a tractable robust reformulation, together with probabilistic feasibility guarantees. We demonstrate that the proposed demand flexibility management can substitute the traditional reserve scheduling services in power systems with high levels of uncertain generation. Moreover, we show that this change does not jeopardize the stability of the grid or violate thermal comfort constraints of buildings. We finally provide a large-scale Monte Carlo simulation study to confirm the impact of achievements.


2018 ◽  
Vol 76 (1) ◽  
pp. 11-26 ◽  
Author(s):  
Christina Klasa ◽  
Marco Arpagaus ◽  
André Walser ◽  
Heini Wernli

Abstract Dynamical processes determining the time evolution of difference kinetic energy (DKE) in a limited-area domain are investigated with the convection-permitting ensemble model COSMO-E for a forecasting period of 4 days. DKE is quantified by means of ensemble variance of the irrotational and nondivergent horizontal wind. For three case studies characterized by contrasting predictability levels of precipitation, it is shown that DKE of the irrotational wind strongly increases during periods of solar-forced moist convective activity and decreases when the latter ceases. The response of DKE of the nondivergent wind is also clearly related to the convective activity, but delayed by a few hours, pointing to interactions between both wind components. Apart from the impact of moist convection, DKE of the nondivergent wind is primarily governed by large-scale advection, imposed at the lateral domain boundaries of the limited-area ensemble. This forcing may also sustain or increase DKE of the irrotational wind when moist convection is absent. Consequently, the large-scale flow and diurnal solar forcing, associated with higher spatiotemporal predictability, determines the overall evolution of the limited-area ensemble variance of the horizontal wind, which increases in the presence of moist convective activity or strong synoptic-scale forcing, and stagnates or decreases otherwise, rendering forecasts of convection-permitting ensembles valuable beyond the very short forecast range.


2014 ◽  
Vol 672-674 ◽  
pp. 227-232
Author(s):  
Xu Zhi Luo ◽  
Hai Feng Li ◽  
Hua Dong Sun ◽  
An Si Wang ◽  
De Zhi Chen

With the fast development of the wind power, security constraints of power systems have become the bottleneck of the acceptable capacity for wind power. The underdamping oscillation modes of the inter-area is an important aspect of the constraints. In this paper, an equivalent model of a power system with wind plants has been established, and the impact of the integration of the large-scale wind power on the inter-area oscillation modes has been studied based on the frequency-domain and time-domain simulations. The results indicate that the damping of inter-area oscillation mode can be enhanced by the replacement of synchronous generators (SGs) with the wind generators. The enhancing degree is up to the participation value of the SGs replaced. The conclusion has been verified by the actual system example of Xinjiang-Northwest grid. It can provide a reference for system programming and operation.


Author(s):  
Roghieh Abdollahi Biroon ◽  
Pierluigi Pisu ◽  
David Schoenwald

The increasing penetration of renewable energy sources in power grids highlights the role of battery energy stor- age systems (BESSs) in enhancing the stability and reliability of electricity. A key challenge with the renewables&rsquo;, specially the BESSs, integration into the power system is the lack of proper dynamic model for stability analysis. Moreover, a proper control design for the power system is a complicated issue due to its complexity and inter-connectivity. Thus, the application of decentralized control to improve the stability of a large- scale power system is inevitable, especially in distributed energy sources (DERs). This paper presents an optimal distributed hybrid control design for the interconnected systems to suppress the effects of small disturbances in the power system employing utility-scale batteries based on existing battery models. The results show that i) the smart scheduling of the batteries&rsquo; output reduces the inter-area oscillations and improves the stability of the power systems; ii) the hybrid model of the battery is more user-friendly compared to the Western electricity coordinating council (WECC) model in power system analysis.


Author(s):  
Olga Patrakeeva

The problem of assessing the effects of infrastructure projects for territories is debatable. Modeling experience has been accumulated today, and elaborated macroeconomic models allow to identify causal relationships between the indicators of transport development and economic growth. The goal of this article is to define a simulation model of assessing the impact of transport projects on the economic growth of Krasnodar Krai exemplified by the Crimean Bridge project. The solution of this scientific problem requires taking into account different factors and complicated interrelationships within the framework of the regional social and economic system under consideration, using methods of system analysis and tools of economic and mathematical simulation. The simulation model reflects the scenario parameters of the capital management policy, highway transport freight turnover, highway transport freight turnover directly connected with the construction of Kerch Straight Bridge, carriage of goods by railway transport, carriage of goods by railway transport directly connected with the construction of Kerch Straight Bridge. The interrelations of this model’s parameters are established by the econometrics methods. In accordance with the produced scenarios the expected median values of the additional increment of the Krasnodar Krai GRP due to the increment of transportation associated with the Crimean Bridge operation are in the range between 0.97 % and 1.1 %. The most conservative scenario presumes the median value of 0.97 % and lower limit of 0.8 %. This tool can be used to assess the direct effect of railway and road construction for other Russian regions. The proposed simulation model will be further expanded by including further distribution functions of scenario variables and additional structural relationships.


2019 ◽  
Vol 17 (6) ◽  
pp. 35-45 ◽  
Author(s):  
Ryan Quint ◽  
Naomi Stringer ◽  
Lisa Dangelmaier ◽  
Irina Green ◽  
David Edelson ◽  
...  

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