Multiple domain behavioral modeling using VHDL-AMS

Advanced control methods for power electronics systems

In the last three decades, there has been an exponential growth in the area of information technology providing the information processing needs of data-driven businesses in government, science, and private industry in the form of capturing, staging, integrating, conveying, analyzing, and transferring data that will help knowledge workers and decision makers make sound business decisions. Data integration across enterprise warehouses is one of the most challenging steps in the big data analytics strategy. Several levels of data integration have been identified across enterprise warehouses: data accessibility, common data platform, and consolidated data model. Each level of integration has its own set of complexities that requir es a certain amount of time, budget, and re sources to implement. Such levels of integration are designed to address the technical challenges inherent in consolidating the disparate data sources. In this paper, we present a methodology based on industry best practices to measure the readiness of an organization and its data sets against the different levels of data integration. We introduce a new Integration Level Model (ILM) tool, which is used for quantifying an organization and data system’s readine ss to share data at a certain level of data integration. It is based largely on the established and accepted framework provided in the Data Mana gement Association (DAMA-DMBOK). It comprises several key data management functions and supporting activities, together with several environmental elements that describe and apply to each functi on. The proposed model scores the maturity of a system’s data governance processes and provides a pragmatic methodology for evaluating integration risks. The higher the computed scores, the better managed the source data system a nd the greater the likelihood that the data system can be brought in at a higher level of integration. Keywords: Big data, multi-agency data integration, data management, data warehouse

In the simulation of power electronics systems, for reasons of computing time and convergence, it may be necessary to use ideal components which generate ideal voltage switchings (steep edges). However, in reality, these voltage variations are far from ideal and to reproduce a voltage closer to reality, it is necessary to model these variations. This is especially important for the study of residual voltage obtained by simultaneous switching, which are present in PWM strategies developped to reduce the impact of the common-mode voltage generated by 3-phase inverters. This paper is focused on the required model accuracy, in order to take into account these residues obtained by the synchronization of switching voltages.

In this work we present a FPGA implementation of the Latency Insertion Method (LIM) to perform simulation of power electronics systems with high switching frequencies (e.g. SiC based power converter with ƒ sw = 100 − 200kHz). We describe how LIM is used to model a buck and a three phase AC/DC converter and how a FPGA solver based on this approach is implemented. Simulation test performed on a Virtex-7 are presented. All real-time simulations are performed with time steps of 40ns and smaller.

The Field Programmable Gate Array (FPGA) offers opportunities for improved performance and design flexibility for digital control of power electronics. However, the complexity of Hardware Description Language (HDL) coding can be a barrier for the design engineer. Presented is a system modeling and development environment for FPGA-based digital control that also has the ability to auto-generate HDL code. The method uses Altera DSP Builder technology in a MATLAB / SIMULINK environment to develop a digital power electronics controller. A full-bridge PWM converter for a solar grid-tie inverter was built and close correlation to the model was demonstrated. The method presented provides complete system simulation of power electronics, while also providing the quality and productivity benefits of auto-code generation.

Low integrity is a challenge for any organization. However, most organizations emphasize integrity without explaining what is required of an individual with high integrity. Exhibiting high integrity is necessary for academics; yet, the level of academic integrity remains unclear. Therefore, the purpose of this study is to examine the integrity level of academicians in a Malaysian public university. This paper shares the findings on the level of integrity of academics based on a questionnaire completed by 213 academicians. Data were collected by survey questionnaire and was analyzed using descriptive and inferential statistics. An overall mean score of 9.45 from a possible 10.0 indicated a high level of integrity among academics. The self-evaluation results by academics also demonstrated that they have attained integrity at a high level for their generic task, teaching and learning, research and publications and service for community with a mean score between 9.36 and 9.49. The value with the highest mean score was for “service to community”, whereas the lowest was for “research and publication”. These findings show that the university has successfully instilled values of integrity among academicians. Nevertheless, the university must continue to enhance academic integrity by exploring religiosity. Using Google Scholar, a literature search identified an Islam-based academic integrity model to explain the quantitative findings. Finally, a mixed method approach and involving all universities in Malaysia are recommended to further the findings of this study.

PurposeThe present work aims to explain how the nonlinear average model can be used in power electronic integration design as a behavioral model.Design/methodology/approachThe nonlinear average model is used in power electronic integration design as a behavioral model, where it is applied to a voltage source inverter based on IGBTs. This model was chosen because it takes into account the nonlinearity of the power semiconductor components and the wiring circuit effects, which can be formalized by the virtual delay concept. In addition, the nonlinear average model cannot distinguish between slow and quick variables and this is an important feature of the model convergence.FindingsThe paper studies extensively the construction of the nonlinear average model algorithm theoretically. Detailed explanations of the application of this model to voltage source inverter design are provided. The study demonstrates how this model illustrates the effect of the nonlinearity of the power semiconductor components' characteristics on dynamic electrical quantities. It also predicts the effects due to wiring in the inverter circuit.Research limitations/implicationsMore simulations and experimental analysis are still necessary to improve the model's accuracy, by using other static characteristic approaches, and to validate the applicability of the model to different converter topologies.Practical implicationsThe paper formulates a simple nonlinear average model algorithm, discussing each step. This model was described by VHDL‐AMS. On the one hand, it will assist theoretical and practical research on different topologies of power electronic converters, particularly in power integration systems design such as the integrated power electronics modules (IPEM). On the other hand, it will give designers a more precise behavioral model with a simpler design process.Originality/valueThe nonlinear average model used in power electronic integration design as behavioral model is a novel approach. This model reduces computational costs significantly, takes physical effects into account and is easy to implement.

Multi-Input converter has gained much more attentions because of the simplify circuit and less cost when implemented in the power system. As a new kind of digital control product, with lower costs, smaller package and higher level of integration, Digital signal controller (DSC), has a very good prospect in the field of digital control. Based on DSC TMS320F28035, this paper presents a new design and implementation for Multi-Input converter in order to realize the reasonable power distribution. All necessary DSC hardware or software techniques and algorithms required to implement the controller are discussed in detail. The steady state and dynamic response performance of the controller is presented in order to demonstrate the effectiveness of this design.

The tracking/rejection of periodic signals constitutes a wide field of research in the control theory and applications area and Repetitive Control has proven to be an efficient way to face this topic; however, in some applications the period of the signal to be tracked/rejected changes in time or is uncertain, which causes and important performance degradation in the standard repetitive controller. This thesis presents some contributions to the open topic of repetitive control working under varying frequency conditions. These contributions can be organized as follows: One approach that overcomes the problem of working under time varying frequency conditions is the adaptation of the controller sampling period, nevertheless, the system framework changes from Linear Time Invariant to Linear Time-Varying and the closed-loop stability can be compromised. This work presents two different methodologies aimed at analysing the system stability under these conditions. The first one uses a Linear Matrix Inequality (LMI) gridding approach which provides necessary conditions to accomplish a sufficient condition for the closed-loop Bounded Input Bounded Output stability of the system. The second one applies robust control techniques in order to analyse the stability and yields sufficient stability conditions. Both methodologies yield a frequency variation interval for which the system stability can be assured. Although several approaches exist for the stability analysis of general time-varying sampling period controllers few of them allow an integrated controller design which assures closed-loop stability under such conditions. In this thesis two design methodologies are presented, which assure stability of the repetitive control system working under varying sampling period for a given frequency variation interval: a mu-synthesis technique and a pre-compensation strategy. On a second branch, High Order Repetitive Control (HORC) is mainly used to improve the repetitive control performance robustness under disturbance/reference signals with varying or uncertain frequency. Unlike standard repetitive control, the HORC involves a weighted sum of several signal periods. With a proper selection of the associated weights, this high order function offers a characteristic frequency response in which the high gain peaks located at harmonic frequencies are extended to a wider region around the harmonics. Furthermore, the use of an odd-harmonic internal model will make the system more appropriate for applications where signals have only odd-harmonic components, as in power electronics systems. Thus an Odd-harmonic High Order Repetitive Controller suitable for applications involving odd-harmonic type signals with varying/uncertain frequency is presented. The open loop stability of internal models used in HORC and the one presented here is analysed. Additionally, as a consequence of this analysis, an Anti-Windup (AW) scheme for repetitive control is proposed. This AW proposal is based on the idea of having a small steady state tracking error and fast recovery once the system goes out of saturation. The experimental validation of these proposals has been performed in two different applications: the Roto-magnet plant and the active power filter application. The Roto-magnet plant is an experimental didactic plant used as a tool for analysing and understanding the nature of the periodic disturbances, as well as to study the different control techniques used to tackle this problem. This plant has been adopted as experimental test bench for rotational machines. On the other hand, shunt active power filters have been widely used as a way to overcome power quality problems caused by nonlinear and reactive loads. These power electronics devices are designed with the goal of obtaining a power factor close to 1 and achieving current harmonics and reactive power compensation.

P02-184 Continuity of care, systems integration and patient transitions: Central or local psychiatric beds? The VELO-project

The technologies that should be developed to make small-scale solid waste processing facilities attractive and viable for small municipalities with solid waste between 50 and 250 tons per day are identified. Research and development needs for refuse derived fuel systems, thermal systems, and biological processes are listed. Selected research and development needs discussed for mechanical processing systems are: develop data bank for low-cost, low-energy shredder options; develop performance data for shredders applied after separation; develop data bank for Trommel performance; and identification and evaluation of low-cost materials separation equipment. Selected research and development needs discussed for thermal systems are: emission levels from solid/waste/to/energy systems; determination of the theoretical efficiencies for thermal processing systems; boiler erosion/corrosion evaluation for systems firing refuse derived fuel; optimization of feed and ash handling systems; refractory life and maintenance requirements; development of 5- to 20-TPD systems; and optimization studies of control systems for small modular incinerators. Selected research and development needs discussed for biological processing systems are: optimum design and operation to maximize gas recovery rates and investigate process configuration alternatives for anaerobic digesters.

We present an approach to model-driven software product line engineering which is based on feature models and domain models. A feature model describes both common and varying properties of the instances of a software product line. The domain model is composed of a structural model (package and class diagrams) and a behavioral model (story diagrams). Features are mapped onto the domain model by annotating elements of the domain model with features. An element of a domain model is specific to the features included in its feature annotation. An instance of the product line is defined by a set of selected features (a feature configuration). A configuration of the domain model is built by excluding all elements whose feature set is not included in the feature configuration. To ensure consistency of the configured domain model, we define constraints on the annotations of inter-dependent domain model elements. These constraints guarantee that a model element may be selected only when the model elements are also included on which it depends. Violations of dependency constraints may be removed automatically with the help of an error repair tool which propagates features to dependent model elements.

Integrating Environmental Management Control Systems - Boosting the Translation of Environmental Strategy into Environmental Managerial Performance

Integration associations of different levels are actively developing in all regions of the world. Eight common markets, namely the European Economic Area (EEA), the Eurasian Economic Union (EEU), the Cooperation Council for the Arab States of the Gulf (GCC), the East African Community (EAC), the Economic Community of Central African States (ECCAS), the Southern Common Market (MERCOSUR), the Central American Common Market (CACM) and the Caribbean Single Market and Economy (CSME) are central. These are integration associations based on free trade and free exchange of all factors of production. The purpose of the study was to identify geographic differences in the depth of integration within the world’s common markets. The depth of integration is studied quantitatively using the index of integration depth developed by the authors. It is based on the principle of common approach to assessing integration across four freedoms, i. e. the movement of goods, services, people and capital, represented in the aggregate index by two indicators, namely openness (the ratio of a particular flow within the common market to the size of the country) and importance (the share of flows within the common market in all external flows). This approach allows to assess the country’s participation in both regional and international movement of production factors. The study revealed that common markets formed on similar principles differ significantly in the depth of integration. In contrast to the developed European common market, participants in the Asian, African and Latin American common markets are characterized by a much more intensive exchange of production factors with third countries than with each other. This is facilitated by the regional specific features of the processes of international economic integration. Only the EEA can be classified as a common market with high level of integration; the EEU, CACM, CSME and EAC are characterised by the low level of integration; and it is very low in the GCC, MERCOSUR and ECCAS. There are many centres of diffusion of integration processes in the EEA and CSME; the CACM, EAC, GCC and MERCOSUR have one main centre and one sub-centre; and there is one supercentre in the EEU. In most cases, the centre’s level of integration is one of the lowest within the market.

In this paper we will present a method to facilitate bachelor students with educational laboratory setups which they can use to build fully operational mechatronic and power electronic systems in the spirit of the internet of things. First we will examine all required components and their position in the overall system. It will be demonstrated that both analog and digital control can be applied to the same power electronics board and that this system can be controlled via a web-server. Starting with the internet connection, a Single Board Computer [SBC] will be able to connect to a web-server running a server-side script for communication with the outside world. The user has access to this web-server and can set parameters. The SBC can control multiple micro-controllers via I2C or USB connections. A micro-controller is then reading signals and giving control signals to a high speed analog control circuitry which in turn can regulate the power electronics. The power electronics regulates the electric motor or actuator, driving the actual applications. The main focus of this paper is on the development of a general power electronics board that facilitates multiple purposes. Several aspects of energy conversion have to be taken into consideration and therefore, the board is made general in such a way, that it can serve as a platform to teach students the variety of DC-DC and DC-AC converters that form the energy conversion backbone in the future IoT.