Adaptive Model Predictive Control Including Battery Thermal Limitations for Fuel Consumption Reduction in P2 Hybrid Electric Vehicles

The primary objective of a hybrid electric vehicle (HEV) is to optimize the energy consumption of the automotive powertrain. This optimization has to be applied while respecting the operating conditions of the battery. Otherwise, there is a risk of compromising the battery life and thermal runaway that may result from excessive power transfer across the battery. Such considerations are critical if factoring in the low battery capacity and the passive battery cooling technology that is commonly associated with HEVs. The literature has proposed many solutions to HEV energy optimization. However, only a few of the solutions have addressed this optimization in the presence of thermal constraints. In this paper, a strategy for energy optimization in the presence of thermal constraints is developed for P2 HEVs based on battery sizing and the application of model predictive control (MPC) strategy. To analyse this approach, an electro-thermal battery pack model is integrated with an off-axis P2 HEV powertrain. The battery pack is properly sized to prevent thermal runaway while improving the energy consumption. The power splitting, thermal enhancement and energy optimization of the complex and nonlinear system are handled in this work with an adaptive MPC operated within a moving finite prediction horizon. The simulation results of the HEV SUV demonstrate that, by applying thermal constraints, energy consumption for a 0.9 kWh battery capacity can be reduced by 11.3% relative to the conventional vehicle. This corresponds to about a 1.5% energy increase when there is no thermal constraint. However, by increasing the battery capacity to 1.5 kWh (14s10p), it is possible to reduce the energy consumption by 15.7%. Additional benefits associated with the predictive capability of MPC are reported in terms of energy minimization and thermal improvement

Aeronautical engineering: A special bibliography with indexes, supplement 49

The bibliography contains 368 abstract citations of reports, journal articles, and other documents concerned with the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. Research and development in aerodynamics, aeronautics, and ground support equipment are also treated. Subject, personal, and contract number indexes are included for ease of access

Battery States Monitoring and its Application in Energy Optimization of Hybrid Electric Vehicles

L'abstract è presente nell'allegato / the abstract is in the attachmen

Optimal free descriptions of many-body theories

Interacting bosons or fermions give rise to some of the most fascinating phases of matter, including high-temperature superconductivity, the fractional quantum Hall effect, quantum spin liquids and Mott insulators. Although these systems are promising for technological applications, they also present conceptual challenges, as they require approaches beyond mean-field and perturbation theory. Here we develop a general framework for identifying the free theory that is closest to a given interacting model in terms of their ground-state correlations. Moreover, we quantify the distance between them using the entanglement spectrum. When this interaction distance is small, the optimal free theory provides an effective description of the low-energy physics of the interacting model. Our construction of the optimal free model is non-perturbative in nature; thus, it offers a theoretical framework for investigating strongly correlated systems

Optimal Sizing and Power Management Strategies of Islanded Microgrids for Remote Electrification Systems

Over the past few years, electrification of remote communities with an efficient utilization of on-site energy resources has entered a new phase of evolution. However, the planning tools and studies for the remote microgrids are considered inadequate. Moreover, the existing techniques have not taken into account the impact of reactive power on component sizes. Thus, this thesis concentrates on optimal sizing design of an islanded microgrid (IMG), which is composed of renewable energy resources (RERs), battery energy storage system (BESS), and diesel generation system (DGS), for the purpose of electrifying off-grid communities. Owing to the utilization of both BESS and DGS, four power management strategies (PMSs) are modeled upon analyzing the impacts of reactive power to chronologically simulate the IMG. In this work, two single-objective optimization (SOO) and two multiobjective optimization (MOO) approaches are developed for determining the optimal component sizes in an IMG. Chronological simulation and an enumeration-based search technique are adopted in the first SOO approach. Then, an accelerated SOO approach is proposed by adopting an improved piecewise aggregate approximation (IPAA)-based time series and a genetic algorithm (GA). Next, an adaptive weighted sum (AWS) method, in conjunction with an enumeration search technique, is adopted in a bi-objective optimization approach. Finally, an elitist non-dominated sorting GA-II (NSGA-II) technique is proposed for MOO of the IMG by introducing three objective functions. The enumeration-based SOO approach ensures a global optimum, determines the optimal sizes and PMSs simultaneously, and offers a realistic solution. The accelerated SOO approach significantly reduces the central processing unit (CPU) time without largely deviating the life cycle cost (LCC). The bi-objective optimal sizing approach generates a large number of evenly spread trade-off solutions both in regular and uneven regions upon adopting the LCC and renewable energy penetration (REP) as the objective functions. Using the MOO approach, one can produce a diversified set of Pareto optimal solutions, for both the component sizes and PMSs, at a reduced computational effort. The effectiveness of the proposed approaches is demonstrated by simulation studies in the MATLAB/Simulink software environment

Aeronautical Engineering: A special bibliography with indexes, supplement 46, July 1974

This special bibliography lists 374 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1974

Management: A continuing literature survey with indexes, March 1975

A special bibliography listing 1,064 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in 1974 is presented