This thesis was made together with Syntronic, a leading design house specializing in advanced productand systems development. One of the major trends in vehicle industry today is the emergence of electricvehicles. One of the main challenges for the electric vehicles is the energy storage capacity whichtogether with powertrain, rolling- and wind resistance losses determines the vehicle range. Therefore,steps are taken in all areas from more efficient electronics to regenerative breaking which have beenwidely adopted, and the hunt for harvesting energy from other areas of the car is on its way. Energydissipated in heat from the shock absorbers can be harvested and some concepts of this have showngood results.The focus of this work was therefore to, based on previous studies, develop and evaluatea new type of shock absorber with integrated energy harvesting.A product development process was used to generate a new or develop a current concept for aregenerative shock absorber. From the product development process a compact hydraulic-electricsystem within the shock absorber were designed and evaluated on its regenerative capabilities with apeak efficiency of 32 percent while also providing an adjustable dampening coefficient. The conceptoffers a compact and affordable design by utilizing a vane pump integrated into the shock absorberpiston.

Indiana University-Purdue University Indianapolis (IUPUI) / The harvested energy of wind can be transferred to the generators either through a gearbox or through an intermediate medium such as hydraulic fluids. In this method, high-pressure hydraulic fluids are utilized to collect the energy of single or multiple wind turbines and transfer it to a central generation unit. In this unit, the mechanical energy of the hydraulic fluid is transformed into electric energy. The prime mover of hydraulic energy transfer unit, the wind turbine, experiences the intermittent characteristics of wind. This energy variation imposes fluctuations on generator outputs and drifts their angular velocity from desired frequencies. Nonlinearities exist in hydraulic wind power transfer and are originated from discrete elements such as check valves, proportional and directional valves, and leakage factors of hydraulic pumps and motors. A thorough understanding of hydraulic wind energy transfer system requires mathematical expression of the system. This can also be used to analyze, design, and predict the behavior of large-scale hydraulic-interconnected wind power plants. This thesis introduces the mathematical modeling and controls of the hydraulic wind energy transfer system. The obtained models of hydraulic energy transfer system are experimentally validated with the results from a prototype. This research is classified into three categories. 1) A complete mathematical model of the hydraulic energy transfer system is illustrated in both ordinary differential equations and state-space representation. 2) An experimental prototype of the energy transfer system is built and used to study the behavior of the system in different operating configurations, and 3) Controllers are designed to address the problems associated with the wind speed fluctuation and reference angular velocity tracking. The mathematical models of hydraulic energy transfer system are also validated with the simulation results from a SimHydraulics Toolbox of MATLAB/Simulink®. The models are also compared with the experimental data from the system prototype. The models provided in this thesis do consider the improved assessment of the hydraulic system operation and efficiency analysis for industrial level wind power application.