The system order reduction via balancing in view of the method of singular perturbation

U radu je predstavljeno nekoliko tehnika za redukciju reda sistema, poznatih iz literature, koje su sve zasnovane na uravnoteženju sistema uz primenu metode singularnih perturbacija. Ove tehnike imaju istu robusnost tačnosti izračunatu u skladu sa H∞ normom sistema redukovanog reda kao i dve tehnike poznate pod nazivom direktno odsecanje i metod balansirane rezidualizacije. Modifikacija ovih tehnika zadržava tačnu vrednost pojačanja jednosmernog signala kakva je kod originalnog sistema i daje aproksimaciju od veoma dobre do odlične tačnosti na nižim i srednjim učestanostima. Efikasnost prikazanih tehnika za redukciju reda modela data je na realnom primeru.This paper presents several techniques for system order reduction, known from literature, all of them based on system balancing by employing the method of singular perturbation. These techniques have the same robustness accuracy evaluated with respect to the H∞ norm of the reducedorder system like two techniques known as the direct truncation and the balancing residualization method. A modification of these techniques preserves the exact DC gain as the original system, and produces from very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order-reduction techniques here presented, a real simulation example is given

Multimodeling Control via System Balancing

A new approach in multimodeling strategy is proposed. Multimodel strategies in which control agents use different simplified models of the same system are being developed using balancing transformation and the corresponding order reduction concepts. Traditionally, the multimodeling concept was studied using the ideas of multitime scales (singular perturbations) and weak subsystem coupling. For all reduced-order models obtained, a Linear Quadratic Gaussian (LQG) control problem was solved. Different order reduction techniques were compared based on the values of the optimized criteria for the closed-loop case where the full-order balanced model utilizes regulators calculated to be the optimal for various reduced-order models. The results obtained were demonstrated on a real-world example: a multiarea power system consisting of two identical areas, that is, two identical power plants

Singular Perturbations and Time-Scale Methods in Control Theory: Survey 1976-1982

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / N00014-79-C-0424U.S. Air Force / AFOSR 78-363

Applications of Singular Perturbation Techniques to Control Problems

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / N00014-79-C-0424National Science Foundation / NSF ECS 82-1763

Application of robust order reduction in modeling and control of real systems and objects in mechanical engineering

Дисертација „Примена робусне редукције реда система у моделовању и управљању реалним објектима у машинству“ је посвећена техникама и методама за редукцију реда линеарних модела, представљених у простору стања, као и условима и ограничењима за њихову примену. Приказан је концепт сингуларних пертурбација и његова примена у редукцији сложености модела система. Размотрене су различите карактеризације линеарних модела великог реда, чије репрезентације моделима у простору стања имају различите временске скале или и мали параметар (имају матрице великих димензија са пуно нула-елемената или са елементима, чији се редови величине веома разликују). Представљени су: сингуларно пертурбовани слабо повезани системи, слабо повезани системи, сингуларно пертурбовани системи, квази сингуларно пертурбовани системи и квази слабо повезани системи. Свака од ових класа представљена је одговарајућим моделом у простору стања неког реалног система. Детаљније је изложен прорачун регулатора за линеаран сингуларно пертурбован систем. Описана је метода балансирања, као и технике за редукцију реда линеарних модела, познате из литературе, које захтевају примену трансформације балансирања: балансирано одсецање, балансирана резидуализација, генералисана балансирана резидуализација, кориговано балансирано одсецање, метода заснована на брзом подсистему уз одбацивање спорог, модификована генералисана балансирана резидуализација, као и реверзна техника резидуализације. Свака од ових техника даје по један модел редукованог реда, полазећи од балансираног модела пуног реда. Технике изложене у овој тези, примењене су на редуковање реда четири модела реалних система. Први је модел бинарне дестилационе колоне са прегревачем и девет подова. Други је модел у простору стања борбене летелице L-1011. Трећи је математички модел каталитички контролисане реакције, из процесне технике. Четврти је математички модел дела електроенергетског система Србије, сачињен од две машине. Изложена је и редукција реда модела нестабилних линеарних система, на основу изабране литературе...The dissertation Application of Robust Order Reduction for Modeling and Control of Real Systems in Mechanical Engineering is dealing with techniques and methods of order reduction for linear models in the state space representation, as well as with conditions and limitations of their applicability. Well known concept of singular perturbations is described with its application in reduction of complexity of the system’s model. Different characterizations of large scale linear models are overviewed, having state space representations who exhibit different time scales or small parameter, too. These models have matrices of large dimensions with many zero-elements or elements with different size order, some very large and others very small. The singularly perturbed and weakly coupled systems, the weakly coupled systems, the singularly perturbed systems, the quasy singularly perturbed systems and the quasy weakly coupled systems are listed and represented here. Each class of these is represented with corresponding state space model of one real system. The design of the regulator for the linear singularly perturbed system is described in detail. The balancing method is analyzed, as well as techniques for the order reduction of linear model’s, known from the literature. These require application of the balancing transformation: the balancing truncation, the balancing residualization, the generalized balancing residualization, the corrected balancing truncation, the method based on the fast subsystem with rejection of the slow subsystem, the modified generalized balancing residualization, as well as the reversed residualization technique. Each of these techniques mentioned gives one model of reduced order, starting from the balanced full order model. Techniques represented in this thesis are applied on order reduction of four real system’s models. The first is the state space model of binary distillation column, with condenser, reboiler and nine plates. The second is the state space model of L-1011 fighter aircraft. The third is a mathematical model of the controlled catalytic reaction, from process engineering. The fourth part is a mathematical model of the part of electric power system of Serbia, consisting of two machines. Described here is the order reduction for models of unstable linear systems as well, based on the chosen references..

Advances in Theoretical and Computational Energy Optimization Processes

The paradigm in the design of all human activity that requires energy for its development must change from the past. We must change the processes of product manufacturing and functional services. This is necessary in order to mitigate the ecological footprint of man on the Earth, which cannot be considered as a resource with infinite capacities. To do this, every single process must be analyzed and modified, with the aim of decarbonising each production sector. This collection of articles has been assembled to provide ideas and new broad-spectrum contributions for these purposes

Global Narratives and the Vulnerable Frontiers: A critical assessment of global climate change communication processes and traditional retentions

Contemporary ecological issues compound environmental communications primary challenge of raising public consciousness and effectively mobilizing agency to mount robust systemic and practical actions. This fundamental challenge persists amidst capitalist enclosure that exacerbates anthropogenic climate change in a manner that indicts current models of macrosocietal planning (Steffen, 2011; Garnaut, 2008). Yet, we know little about our capacity to raise public consciousness and therefore incite reparatory actions in the environmental domain (Foxwell-Norton & Lester, 2017). This is most consequential in resource-dependent communities, the frontiers of climate impact. Critical aspects of life, including subsistence on rainfed agriculture, are manifestly undermined by current and projected climate change related impacts. Given the urgent existential implications of inaction or even inadequate action, this study seeks to optimize climate change communication in accordance with transformative and reparatory consciousness. It links the field of climate change communications with critical perspectives in Communication for Social Change and integrates the reparatory notion of climate justice to explicitly highlight the ethico-political terrain on which communicative actions must be directed to be commensurate with the distinct variability, high degree of permanence and multidimensionality of anthropogenic challenges. The comparative and cross-cultural study is based on a representative purposive sample of 300 drawn from across 17 indigenous and traditional villages in Fiji, India and Belize that typifies heightened and disproportionate levels of vulnerability. It employs a socio-cultural elicitation and analytical framework to delineate and probe climate change perception, disposition and actions across 14 dimensions with keen attention to contextually variable group membership, alongside standard demographic variables. Probing these interpretive communities uniquely illuminates how discrete group membership structures climate disposition. It also highlights contextual intervention levels for knowledge improvement and mobilization generally and across specific dimensions, including religious and nature-oriented fatalism, discrete motives and potential sources of leadership. Definitively, it offers globally relevant recommendations for optimizing communication processes in resource-dependent communities across three pathways: coping, resilience and transformation. This is premised on comparative analysis of the findings of the socio-cultural elicitation process against climate change communications general acceptance of core communication principles regarding risk perception, message construction, resonance, motive, intervention levels and engagement frames

Renewable Energy

The demand for secure, affordable and clean energy is a priority call to humanity. Challenges associated with conventional energy resources, such as depletion of fossil fuels, high costs and associated greenhouse gas emissions, have stimulated interests in renewable energy resources. For instance, there have been clear gaps and rushed thoughts about replacing fossil-fuel driven engines with electric vehicles without long-term plans for energy security and recycling approaches. This book aims to provide a clear vision to scientists, industrialists and policy makers on renewable energy resources, predicted challenges and emerging applications. It can be used to help produce new technologies for sustainable, connected and harvested energy. A clear response to economic growth and clean environment demands is also illustrated