Component-based simulation for a reconfiguration study of transitic systems

This paper is organized as follows. Part A presents the context of reconfiguring transitic systems and the main idea in implementing the decision step. It comprises sections 1 to 3. Section 3 presents an example that illustrates the concepts presented in the next sections. Parts B and C express the models and principles used to simulate transitic systems, the result of which will be helpful for choosing the new configuration. Part B focuses mainly on models. It comprises sections 4 to 6. Part C focuses mainly on simulation principles. It comprises sections 7 to 10

Frameworks for Component-based Simulation

AbstractThe need to reduce development costs of simulation models has led to recent efforts for setting simulation standards that foster model reuse and interoperability. Specifically, the High Level Architecture (HLA) is a new simulation standard supported by the US Defense Modeling and Simulation Office (DMSO). It has been adopted as the standard technical architecture for all US Department of Defense simulations. In the meantime, the commercial sector has had successful efforts in developing enabling technologies for distributed computing; namely, the Common Object Request Broker Architecture (CORBA) by the Object Management Group (OMG). CORBA is a large and complex set of specifications and protocols that utilizes the objectoriented paradigm to achieve distributed object-oriented computing environments that allow object interoperability and reuse. When used as an infrastructure for simulation model reuse and interoperability, both HLA and CORBA exhibit merits and limitations. Since HLA and CORBA were developed independently, need exists for a comparative evaluation of the two architectures as a basis for component-based simulation. In this paper, both HLA and CORBA are presented in the context of component-based simulation model development and interoperability. The two architectures are compared against four comparison criteria that are related to their conceptual foundation and design

Simulator adaptation at runtime for component-based simulation software

Component-based simulation software can provide many opportunities to compose and configure simulators, resulting in an algorithm selection problem for the user of this software. This thesis aims to automate the selection and adaptation of simulators at runtime in an application-independent manner. Further, it explores the potential of tailored and approximate simulators - in this thesis concretely developed for the modeling language ML-Rules - supporting the effectiveness of the adaptation scheme.Komponenten-basierte Simulationssoftware kann viele Möglichkeiten zur Komposition und Konfiguration von Simulatoren bieten und damit zu einem Konfigurationsproblem für Nutzer dieser Software führen. Das Ziel dieser Arbeit ist die Entwicklung einer generischen und automatisierten Auswahl- und Adaptionsmethode für Simulatoren. Darüber hinaus wird das Potential von spezifischen und approximativen Simulatoren anhand der Modellierungssprache ML-Rules untersucht, welche die Effektivität des entwickelten Adaptionsmechanismus erhöhen können

Implementation of Component-based Simulation Support Tool for Conceptual Design

Presented paper speaks about the problem of conceptual design stage simulation support. Simulation support is a very useful part of conceptual design system due to capability to verify ideas in early design stages. The problem excluding classical simulation tools is lack of information about designed device, is inconsistency and uncertainty. Thus specialised tool must be developed. The component-oriented editor of component descriptions and models is presented. This tool enables to describe components not only in terms of algebraic equations, but also by fuzzy rules. The problem of dynamic work with uncertainty representation during simulation and design processes is also solved. Presented tool also differentiates from standard tools like Mathematica or Matlab in its ability to work with component-based models, where each component is described from many aspects and only few of them are valid in concrete use. The tool must be able to select relations relevant in concrete simulation task and omit the rest.

OSA: an Integration Platform for Component-Based Simulation

Poster abstract.International audienceMany discrete-event simulators are developed concurrently, but with identical or similar purpose. This poster presents the Open Simulation Architecture (OSA), a discrete-event component-based simulation platform whose goal is to favor the reuse and integration of simulation software components and models. To favor reuse, OSA uses a layered approach to combine the modeling, simulation, and related concerns, such as instrumentation or deployment. OSA is both a testbed for experimenting new simulation techniques and a tool for real case studies. The ability of OSA to support challenging studies is illustrated by a Peer-to-peer system case study involving millions of components

State-variable modelling of CLL resonant converters

The paper presents the derivation and application of state-variable models to high-order topologies of resonant converters. In particular, a 3rd order CLL resonant circuit is considered with bridge rectification and both a capacitive output filter (voltage output), and an LC output filter (current output). The state-variable model accuracy is verified against component-based simulation packages (Spice) and practical measurements, and it is shown that the resulting models facilitate rapid analysis compared to their integration-based counterparts (Spice, Saber), without the loss of accuracy normally associated with fundamental mode approximation (FMA) techniques. Moreover, unlike FMA, the models correctly predict the resonant peaks associated with harmonic excitation of the tank resonance. Subsequently, it is shown that excitation of the resonant tank by odd harmonics of the input voltage can be utilised to provide overcurrent protection in the event of an output short-circuit. Further, through judicious control of operating frequency, it is shown that 'inductive' zero voltage switching (ZVS) can still be obtained, facilitating reductions in gate-drive switching losses, thereby improving efficiency and thermal management of the supply under fault conditions. Although the results are ultimately generic to other converter counterparts, measured results from two prototype 36 V input, 11-14.4V output, 3rd - order CLL converters are included to practically demonstrate the attributes of the proposed analysis and control schemes

Component based performance simulation of HVAC systems

The design process of HVAC (Heating, Ventilation and Air Conditioning) systems is based upon selecting suitable components and matching their performance at an arbitrary design point, usually determined by an analysis of the peak environmental loads on a building. The part load operation of systems and plant is rarely investigated due to the complexity of the analysis and the pressure of limited design time. System simulation techniques have been developed to analyse the performance of specific commonly used systems: however these 'fixed menu, simulations do not permit appraisal of hybrid and innovative design proposals. The thesis describes research into the development of a component based simulation technique in which any system may be represented by a network of components and their interconnecting variables. The generalised network formulation described is based upon the engineer's schematic diagram and gives the designer the same flexibility in simulation as is available in design. The formulation of suitable component algorithms using readily available performance data is discussed, the models developed being of a 'lumped parameter' steady state form. The system component equations are solved simultaneously for a particular operating point using a gradient based non-linear optimisation algorithm. The application of several optimisation algorithms to the solution of RVAC systems is described and the limitations of these methods are discussed. Conclusions are drawn and recommendations are made for the required attributes of an optimisation algorithm to suit the particular characteristics of HVAC systems. The structure of the simulation program developed is given and the application of the component based simulation procedure to several systems is described. The potential for the use of the simulation technique as a design tool is discussed and recommendations for further work are made