creator Niu, Geng advisor Krishnamurthy, Mahesh Environmental issues and fossil fuel depletion push the evolution of transportation and electrified transportation into the most likely next generation. However, there are several challenges in electrification with the major concerns involving the energy storage system. A hybrid energy storage system may provide an opportunity to improve the energy storage system of applications in transportation electrification. Hydraulic systems have been a mature technology for a long time and this study proposes a hydraulic add-on for electric vehicles. The high power density of a hydraulic accumulator could absorb high frequency regenerative braking and support battery discharging during acceleration, which will extend the driving range and reduce the current stress of the battery pack. Several models and controls have been created to evaluate hydraulic add-ons in di↵erent applications. The simulation results show a roughly 30% current stress drop and up to 25% energy saving (Wh/km) on average for city buses and delivery trucks over di↵erent driving cycles. A scaled down prototype vehicle with a novel electric hydraulic hybrid powertrain based on a go-kart chassis was built to perform road tests to validate the simulations results. Submitted by Erma Thomas (thomase@iit.edu) on 2018-03-16T19:26:07Z No. of bitstreams: 1 etdadmin_upload_523617.zip: 12708167 bytes, checksum: fdb116dc460952fe4b4b042082db1578 (MD5) Made available in DSpace on 2018-03-16T19:26:07Z (GMT). No. of bitstreams: 1 etdadmin_upload_523617.zip: 12708167 bytes, checksum: fdb116dc460952fe4b4b042082db1578 (MD5) Previous issue date: 2017-07 Ph.D. in Electrical Engineering, July 2017 2017 2017-07 http://hdl.handle.net/10560/4214 en Accumulator Electric vehicle Energy storage Fluid power Hybrid powertrain Hydraulics Dissertation born digital application/pdf In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access ECE / Electrical and Computer Engineering Illinois Institute of Technology Affiliated department