It is the objective of this work to develop a computational framework for multi-rate/multi-scale modeling and simulation of power electronics and energy conversion systems for hardware-in-the-loop testing on multi-domain simulation platforms. Based on high-fidelity models of components and subsystems of power and energy systems, numerically rigorous, order-reduction techniques are used to extract several levels of interconnected simulation resolutions from the high-order detailed model. The resulting multi-resolution simulation offers rapid and accurate simulation of the overall systems from a general to a detailed consideration. The computational prototyping framework for switched linear systems, nonlinear systems, and systems with controllers is to be developed. Thereafter, the framework will be extended to ?systems of systems? and other concepts, like flexible nested simulation and co-simulations. At each stage, the numerical reduction techniques and corresponding flexible framework are to be validated with several hardware prototypes of power electronics and energy conversion systems.
Intellectual Merit:
The proposed methodology addresses the tradeoff between the modeling and simulation accuracy and speed. The accuracy is provided through high-fidelity component models and physics-based approaches. The simulation speed and stability is ensured by numerically rigorous order reduction techniques. The resolution of the simulation environment is adjusted arbitrarily upon user discretion, and the signal integrity is preserved. Moreover, since this approach is systematic and automatable, there is less need for expert knowledge. From a control perspective, it provides a framework to implement hardware in the loop and real-time controller concepts. Moreover, the framework comprises a multi-domain simulation environment.
Broader Impacts:
The development of this computational prototyping framework will allow aggregated and aggressive design, analysis, and optimization approaches in power and energy systems, in particular large solar systems, wind farms, advanced electric ship, and hybrid vehicles. This will help accelerate these technologies to adoption, creating energy saving and positive impacts on environment, sustainability, and geopolitics. For educational outreach, undergraduates from different engineering disciplines are to be employed. The recruitment strategy will target underrepresented groups in particular. The team will promote education as an integrated part of this project and will publish the educational aspects of this project. The material will also be used in an advanced power electronics course. Furthermore, a monograph will be published on the developed techniques and will be shared freely via the internet
Intellectual Merit: Research findings affect the paradigm of modeling, simulation, optimization, and control for power and energy systems. In particular, reported results break the tradeoff between the physical modeling and numerical simulation accuracy and speed. The accuracy is guaranteed through high-fidelity component models and physics-based approaches. The simulation speed and stability is ensured by numerically rigorous order-reduction and waveform relaxation techniques. Reachability analysis frameworks are developed for computationally tractable model verification and validation of power electronics systems. Reachability analysis assures safe and proper operation of power electronics systems within a given time span, without resorting to a time-exhaustive brute-force simulations. Multiport power converters are developed for DC power processign and energy conversion. They provide a reliable and flexible means to integrate a large, heterogeneous set of distributed energy DC resources (e.g., photovoltaic, rectified wind, fuel cells) while serving a diverse set of dc loads. Multiport converters can play the role of power processors, actualizing the concept of small-scale energy distribution in future DC grids. This enables a paradigm shift from many single-tasked converters to a few multi-tasked intelligent converters. The sparse communication and computationally efficient control environments are developed for truly distributed control paradigms for small-scale DC and AC energy distribution systems. It helps address main challenges that prevent proliferation of emerging energy systems by eliminating the role of a computationally-intensive centralized controller, using a low-bandwidth sparse communication network that reduces complexity and cost of communication, and offering true plug-and-play capability that can accomodate any new source without the need for structural redesign of controllers. The published work is in reduced-order physical modeling of energy storage and magnetic components, multi-resolution simulation of power converters, multiport DC power processing, and localized computation for distributed control paradigms. Several multiport power electronics converters, storage component characterization setups, and a fully functional DC microgrid systems have been developed and used for hardware verification of proposed control, computation, and communication platforms in power processing and energy conversion systems. This body of knowledge has led to tens of articles published in peer-reviewed journals, conference proceedings, and book chapters including invited articles, best paper awards, and featured cover articles. Broader Impact: Developed tools and converter topologies will affect autonomous renewable energy generation/storage systems, modular microgrids, and hybrid electric vehicles that have noticed significant growth lately due to natural resource depletion, global socio-political scenarios, federal mandates, and economical incentives. Electrical Engineering is moving toward automated computer-aided design and analysis at an ever-increasing pace. From the perspective of numerical tools developed, this computational prototyping framework will allow aggregated and aggressive design, analysis, and optimization approaches in power and energy systems, in particular large solar systems, wind farms, advanced electric ship, and hybrid vehicles. This translates into noticeable energy saving, with great impacts on environment, sustainability, and geopolitics. It alleviates the limitations imposed by the human factor and export knowledge in providing a flexible modeling and simulation environment in power and energy area. Multi-domain computational/virtual prototyping platforms are most suitable candidates for industry's ultimate design/analysis tools as well as energy research and education. Moreover, distributed controllers with localized computation provides a failure-safe control, computation, and communication environment for mission-critical applications such as electric ships and all electric airplanes, data centers, forward operating bases, and remote hospitals. The PI has given 11 invited talks on "computational prototyping for energy systems" in academic and industrial settings. Three special issues have been arranged in different IEEE journals on topics pertaining to this research to gather experts from power electronics, power sytstems, control and computation societies. Two masters thesis and two PhD dissertations have been supported by this grant, leading to 2012 Joseph J. Suozzi INTELEC fellowship from IEEE Power Electronics Society. Another PhD student has accepted a tenure-track assistant professor position. Four PhD students, including two female students, were hosted to do research. Four undergraduate researchers, including a female, Hispanic student and a mechanical engineer, have worked on the REU supplement of this Award. The research findings have been embedded in undergraduate- and graduate-level power electronics and graduate-level electric motor drives courses at the University of Texas-Arlington, where more than a hundred students have been exposed to analysis, simulation, control, and computation in power electronics and energy conversion systems. This help address the imminent shortage of qualified power engineers due to combined effect of the diminishing student interest and an aging workforce.
