Compact Car Regenerative Drive Systems: Electrical or Hydraulic

Abstract

The objective of the research is to address the power density issue of electric hybrids and energy density issue of hydraulic hybrids by designing a drive system. The drive system will utilize new enabling technologies such as the INNAS Floating Cup pump/pump motors and the Toshiba Super Charge Ion Batteries (SCiB). The proposed architecture initially included a hydraulic-electric system, where the high power braking power is absorbed by the hydraulic system while energy is slowly transferred from both the Internal Combustion Engine (ICE) drive train and the hydraulic drive train to the electric accumulator for storage. Simulations were performed to demonstrate the control method for the hydraulic system with in-hub pump motors. Upon preliminary analysis it is concluded that the electric system alone is sufficient. The final design is an electric system that consists of four in-hub motors. Analysis is performed on the system and MATLAB Simulink is used to simulate the full system. It is concluded that the electric system has no need for a frictional braking system if the Toshiba SCiBs were used. The regenerative braking system will be able to provide an energy saving from 25% to 30% under the simulated conditions.