Promotion of energy efficiency and environmental protection are major challenges in future energy applications due to the rising prices in petroleum oil and environmental impacts. Rapidly growing technologies such as hybrid electric vehicles (HEVs) and electric power generation are the best examples of the emerging need to incorporate efficiency, reliability, security, safety, and environmentally friendliness into the energy systems. Due to lack of proper matching between the source and load dynamic characteristics, maintaining the operating conditions at optimal point is not possible in conventional energy application. It has been proven that employing energy storage systems improves the efficiency and reliability of the electric power generation as well as power train of the vehicles. This CAREER proposal will investigate the feasibility and implementation trends of integration of the two systems while they both use the same energy storage system. The required building blocks, tools, and technologies for future cyberinfrastructure development will also be identified. In the future envisioned by this creative proposal, by the year 2020, at least ten percent of the vehicles will be in the form of a hybrid car with an onboard energy storage unit. The vehicles are plugged in to the power grid while they are not in use; hence, while being charged, the onboard energy storage unit will be used for the grid regulation and peak load shaving purposes. The electric energy stored in the vehicle will be used to provide parts of or the entire traction force while the vehicle is in use. Intelligent power management strategy and proper communications between the vehicle and power grid as well as the required power electronic components are the main focus of this proposal. The proposed plan is to devise a new comprehensive approach to the applications of energy storage units in power systems. The main intellectual merit of the proposed project is to integrate the transportation and electric power generation sectors in order to improve the efficiency, fuel economy, and reliability of both systems. This task is performed via integration of the onboard energy storage units of vehicles with the power grid by power electronic converters and communication systems. The Principal Investigator (PI) has strong knowledge and significant accomplishments to be able to carry out the proposed work. He has been in the process of developing new undergraduate and graduate courses as well as laboratories at the University of Missouri-Rolla (UMR). The proposed research and education activities will improve the study of the applications of power electronics and energy storage systems in power and energy systems by integrating the process of learning and discovery. Students at all levels will be exposed to discovery-based exercises and creative research-based educational tools. Furthermore, the cutting edge research and scientific advances will be delivered in the classroom, laboratory, and field. Different workshops in the related fields of hybrid vehicles, renewable energy sources, fuel cells, and power electronics will be designed to promote the recruitment, training, and professional development of high school students, teachers, fire marshals, paramedics, and general public. Minority and female students will be included to participate in the proposed research and education activities. Collaborations with institutions, faculty members, and students who are members of underrepresented groups will be established. This project also fosters potential research collaborations and communications between UMR, HEV manufacturers, power utility companies, and other involved universities and research institutes. Another impact of the proposed project is the identification and establishment of highest quality multi-disciplinary interaction with other fields of engineering including computational intelligence, controls, and communications. The results of the proposed activities will be disseminated through presentations, tutorials and papers at local, national and international seminars, conferences, and workshops. The broader community of general public, code officials, and policy-makers will also be provided with the analysis, interpretation, and synthesis of the proposed research and education results through presentations and public media in order to communicate in a broader context.
Major research outcomes of the project are: 1) Double-input power electronic converters: The energy storage unit is one of the most important subsystems in the structure of a plug-in hybrid electric vehicle since it directly impacts the performance, fuel economy, cost, and weight of the vehicle. New structures for the energy storage unit, which utilize both batteries and ultracapacitors, were investigated in this project. Several new power electronic topologies including double-input buck-buck and double-input buck-buckboost converters were derived. Also, several linear and nonlinear control algorithms were devised. 2) Battery charge equalization: Plug-in hybrid vehicles need an energy storage unit that is reliable during the lifetime of the car. Battery and ultracapacitor capacity imbalances stemming from manufacturing and ensuing driving environment and operational usage affect voltage levels, which must adhere to strict limits to ensure the safety of the driver. A double-tiered capacitive charge shuttling technique to balance the battery or ultracapacitor cell voltages was devised. 3) Effect of PHEVs on the power grid: While plug-in hybrid electric vehicles (PHEV) partially rely on the electricity from the power grid, they raise concerns about their negative impacts on power generation, transmission, and distribution installations. Positive or negative impacts of PHEVs on the power grid cannot be thoroughly examined unless extensive data on the utilization of each individual PHEV are available. For instance, in order to estimate the aggregated impact of PHEVs on the electricity demand profile, one needs to know i) when each PHEV would begin its charging process, ii) how much electrical energy it would require, and iii) how much power would be needed. This research effort extracted and analyzed the data that was available through national household travel surveys (NHTS). The objective was to obtain various PHEV charging load profiles (PCLP). The project also developed a model for examining the existing power system capacity to meet the PHEV load demand, considering the charging request rate, the energy requirements of PHEVs, and the available power capacity. Major educational outcomes of the project are: 1) Workforce training: Several graduate students at M.Sc. and Ph.D. levels conducted research on hybrid and plug-in hybrid electric vehicles. Their work lead to the completion of several theses and the publication of many conference and journal articles. Also, many undergraduate students were engaged in related research activities. 2) Course development: Two new courses related to the topic of the project were developed. One of the courses which is titled "EE 309 Electric-Drive Vehicles" is a senior/graduate level course. This course is offered once a year. The second course which is titled "EE 409 Advanced Electric-Drive Vehicles" is a graduate-level course. This course is offered every other year.
