Real-Time Simulation of Efficient Energy Management Algorithms for Electric Vehicle Chargers

Transportation electrification is happening at a rapid pace around the globe in response to the climate change mitigation measures taken by the regulatory agencies to curb tailpipe emissions. As the electric vehicle technology evolved, the size of on-board storage units has increased, which require charging from an external energy source. Renewable charging of electric vehicles is an attractive option to reduce the carbon footprint of an electric vehicle. The intermittent nature of the renewables necessitates a storage unit to provide continuous power. With a battery complementing solar generation, a power converter is deployed to interface these sources and storage units with the electric vehicle for charging. The converter shall now have to operate to quench the charging requirements by sourcing power from solar generation and storage elements. The converter also has to capture the generated solar power during the non-charging period and store it in the battery. All these functional requirements demand a robust energy management strategy to utilize all available sources and storage units efficiently without compromising load requirements. A Stateflow-based energy management algorithm for a three-port converter is proposed in this work. The proposed algorithm is implemented using OPAL-RT, and the real-time simulation results are presented

User Experience for Model-Driven Engineering : Challenges and Future Directions

Since its infancy, Model Driven Engineering (MDE) research has primarily focused on technical issues. Although it is becoming increasingly common for MDE research papers to evaluate their theoretical and practical solutions, extensive usability studies are still uncommon. We observe a scarcity of User eXperience (UX)-related research in the MDE community, and posit that many existing tools and languages have room for improvement with respect to UX [26], [44], [37], where UX is a key focus area in the software development industry. We consider this gap a fundamental problem that needs to be addressed by the community if MDE is to gain widespread use. In this vision paper, we explore how and where UX fits into MDE by considering motivating use cases that revolve around different dimensions of integration: model integration, tool integration, and integration between process and tool support. Based on the literature and our collective experience in research and industrial collaborations, we propose future directions for addressing these challenges

The Graph Rewriting and Transformation Language: GReAT

In this paper, we describe the language and features of our graph transformation tool, GReAT.We begin with a brief introduction and motivation, followed by an overview of the actual language, the modeling framework, and the tools that were written to support transformations. Finally, we compare GReAT to other similar tools, discuss additional functionality we are currently implementing, and describe some of our experiences with the tool thus far

Enhancing Graphical Model-Based System Design: An Avionics Case Study

Graphical model-based system design is very appealing. However, there exist many different formalisms, with different semantics---as far as they do have well-defined semantics---and differing capabilities of the accompanying tools. In this paper, we present a case study from the avionics domain and report on the experiences in using different modeling languages and tools. The focus here is on the pragmatics of modeling, i. e., the practical process of building and inspecting graphical models. The underlying application is a high-lift ï¬ap system, which is highly safety-critical and served as a demonstrator within the Dependable Embedded Components and Systems (DECOS) project that explored the design of distributed dependable systems build on time-triggered architectures. Specifically, we compare a realization in the Safety Critical Application Development Environment (SCADE), a commercial tool from Esterel-Technologies, with a design in the Kiel Integrated Environment for Layout (KIEL), a research tool that allows to explore novel model handling paradigms. Hence we compare traditional graphical drag-and-drop WYSIWYG modeling with alternative, productivity enhancing approaches. We conclude with a brief outlook on future extensions which will tightly integrate with existing tools based on the Eclipse platform

Modeling and Control in Matlab for ABB's Control Builder

One problem when new controllers or control systems are built is the test of the controllers or the control systems. One way to test the controller is to build a real process to test the controller against. Another way to test the controller is to build the process-model in some kind of computer simulation tool. The advantages of using a simulation tool in a computer are quite many. For example it is often quicker to build the process-model in a computer than to build a real process. It is also often quicker and easier to change some parameters in a model built in a computer simulation tool, than to change the parameters in a real process. In this master thesis a lot of verifications are made to confirm if it is possible to make real-time simulations of process-models build in Matlab/Simulink, and controllers implemented in ABB's Soft Controller. The connection between the process-models in Matlab/Simulink and the controller, implemented in the Soft Controller, is made via ABB's commercial OPC-MMS Server, connected to the Soft Controller, and a Gateway application, connected between the OPC-MMS Server and Matlab/Simulink. The simulation work as it should if the user of this simulation tool is aware of the delays that will appear due to the different sampling stages of the system. The possibilities with this kind of simulations are that test of function blocks (FB) and control modules (CM) used in ABB's Control Builder can be made in an easy way. Another possibility is to show customers improvements that can be made in their control system. </p

Assessing and augmenting SCADA cyber security: a survey of techniques

SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability

Definition of a Type System for Generic and Reflective Graph Transformations

This thesis presents the extension of the graph transformation language SDM (Story Driven Modeling) with generic and reflective features as well as the definition of type checking rules for this language. The generic and reflective features aim at improving the reusability and expressiveness of SDM, whereas the type checking rules will ensure the type-safety of graph transformations. This thesis starts with an explanation of the relevant concepts as well as a description of the context in order to provide the reader with a better understanding of our approach. The model driven development of software, today considered as the standard paradigm, is generally based on the use of domain-specific languages such as MATLAB Simulink and Stateflow. To increase the quality, the reliability,and the efficiency of models and the generated code, checking and elimination of detected guideline violations defined in huge catalogues has become an essential, but error-prone and time-consuming task in the development process. The MATE/MAJA projects, which are based on the use of the SDM language, aim at an automation of this task for MATLAB Simulink/Stateflow models. Modeling guidelines can be specified on a very high level of abstraction by means of graph transformations. Moreover, these specifications allow for the generation of guideline checking tools. Unfortunately, most graph transformation languages do not offer appropriate concepts for reuse of specification fragments - a MUST, when we deal with hundreds of guidelines. As a consequence we present an extension of the SDM language which supports the definition of generic rewrite rules and combines them with the reflective programming mechanisms of Java and the model repository interface standard JMI. Reusability and expressiveness are not the only aspects we want to improve. Another fundamental aspect of graph transformations must be ensured: their correctness in order to prevent type errors while executing the transformations. Checking and testing the graph transformations manually would ruin the benefit obtained by the automation of the guideline checking and by the generic and reflective features. Therefore, we propose in this work a type-checking method for graph transformations. We introduce a new notation for rules of inference and define a type system for SDM. We also proposed an algorithm to apply this type system. We illustrate and evaluate both contributions of our work by applying them on running examples. Proposals for other additional SDM features as well as for possible improvements of our type checking open new perspectives and future research to pursue our work

Bidirectional DC-DC Converter for Supercapacitor as DC-bus Stabilization Element

The demand for renewable energy from wind and solar is increasing. These energy sources are intermittent and unpredictable to a degree and require a stable but fast responding DCgrid. This is achieved by extending the requirements of the DC-grid to its stabilization element and introducing high power density energy storage. The supercapacitor is investigated in this regard to be utilized as a stabilization element. Its fast electric response makes the supercapacitor an excellent energy storage device that works well with other energy storage devices like batteries and fuel cells but also standalone. An isolated bidirectional DC-DC converter is necessary to control the supercapacitor’s power flow and utilize its advantages fully. Firstly, an isolated bidirectional DC-DC converter is simulated and integrated with a supercapacitor in Matlab®/Simulink® to meet a specific system requirement. The DC-DC converter is presented with the dual active bridge topology and single-phase-shift control strategy. Based on the results, it is investigated if the supercapacitor is a good stabilization element for a DC-microgrid. Secondly, a supercapacitor system with integrated cell management, current and voltage sensing, over-voltage protection, and compact design is developed. The design is flexible, where one module can be connected in series or parallel to fit a custom design. In this thesis, six modules are necessitated to meet the system requirement. It is desirable to first test a prototype of one module before assembling the entire energy storage. The supercapacitor prototype is tested in the lab with a DC-load, and its transient response is compared with a simulated supercapacitor. A conference paper on the topic of supercapacitor and lithium-ion batteries is submitted for IEEE ICECCME2021. This paper presents our results that visualize the difference in transient response between the simulated and physical energy storage devices.Masteroppgave i energiENERGI399MAMN-ENER