چكيده به لاتين
The shortage of fossil fuels and environmental pollution resulted from these resources, population growth and mechanized human services cause the utilization of new resources and storage systems, more exploitation of energy and optimization process. Replacement of renewable energy resources necessitates the utilization of new energy manufacturing, storage, and control systems which are under development. The fuel cell has a high density of energy production, but it does not have the capacity to respond quickly to voltage variations and the required electric current Therefore, auxiliary battery is used to provide the load power requirement. Despite its energy density, the battery has a relatively low power density and short cycle life, which prevents to use it in high-power systems such as braking and load balancing. In contrast to batteries, supercapacitors have a much higher specific surface area and provide larger amounts of system necessary energy over a much shorter time interval. Therefore, supercapacitors are fully compatible for applications requiring the supply of energy-intensive pulses in short periods of time.And have contributed to the fuel cells and batteries in the hybrid power generation system. And according to their reliability and stability can be widely used in storage and energy management systems. In this thesis, carbon nanotube are used to build supercapacitor for their unique physical and chemical properties (including high electrical conductivity and good ability to connect directly to the current collector). And Valuable results have been achieved by using the composite structure of carbon nanotubes and metal oxides in order to increase electrical conductivity, direct connection of carbon nanotubes to the current collector to reduce resistance and improve the power density. In the following, The automotive energy management system was designed with consideration of braking system, battery and the supercapacitor, and with the innovative supercapacitor simulation in the GTPOWER software, the effects of changing supercapacitor “SOC” on the improvement of the standard driving cycles have been evaluated. The results of the experimental studies show that the electrochemical properties of the pure carbon nanotubes have improved significantly after the addition of cobalt oxide and the proposed composite. That the main reason of it is about synergistic effect of nanoparticles and metal oxide that the developed supercapacitor is capable to use in high energy storage systems. In the following, we use GT-Power and MATLAB Simulink software for modeling and simulating an electric car with hybrid battery / supercapacitor sources and considering a brake energy recovery system. An energy management and control system designed for it and in the results we have been investigated the Car response for required power and power supplied from battery and supercapacitor in different driving cycles and other parameters such as speed, power, etc are analyzed and discussed in the third and fourth chapters. In this thesis, the energy management system is designed based on supercapacitor and battery charge level with respect to vehicle kinetic energy and acceleration at different times and maximum utilization of brake recovery energy. In this thesis, the energy management system is designed based on supercapacitor and battery charge level considering vehicle kinetic energy and acceleration at different times and maximum utilization of brake recovery energy. So Supercapacitor and battery bank energy management system design has been developed based on minimum discharge control and power requirements of sources to obtain storage and use of braking energy. Normally the battery is the main source and the supercapacitor is an auxiliary source and the supercapacitor provides the surplus power required by the vehicle which the battery cannot supply. The energy management system is designed in terms of vehicle acceleration into three general modes: vehicle acceleration strategy, vehicle constant speed strategy and finally braking and acceleration and speed reduction (energy recovery) strategy. Then, the performance of the US and European Urban Driving Cycle and Test was evaluated and the energy management system was optimized with respect to supercapacitor and battery charging levels. Then, the performance of the US and European Urban Driving Cycle was evaluated and the energy management system was optimized considering supercapacitor and battery charging levels. In the result the graphs of Distance, speed and acceleration variations, external resistive forces, average axial force, motor and braking power, comparing engine power demand and power management power supply, battery and supercapacitor charge level during the driving cycle and etc. is described and discussed in detail. The results show that the supercapacitor is aiding the battery in acceleration and speed control processes And according to Relatively low capacity (40 amps) of battery intended for the simulated model compared to the 90 amps batteries used in commercial electric cars, If the supercapacitor isn’t allocated to the energy management system It wasn’t possible for single battery to Supply of car power required during this cycle. And this is a confirmation for importance of minifying battery size, using of wasted energy and related economic issues in the car.
