Design and implementation of a series hydraulic hybrid propulsion system to increase regenerative braking energy saving range

Environmental contamination has prompted researchers to offer approaches and solutions in a variety of fields, including hybrid drive train. A novel series hydraulic circuit for a regenerative braking system has been presented in order to expand the energy-saving range of regenerative braking and remove friction braking. In various driving scenarios, the generated hydraulic torque performs deceleration. On the basis of the type of deceleration, the single and dual braking modes are examined. In the single braking mode, the required torque is produced by a change in pump output flow, but in the dual braking mode, the torque is provided by simultaneous changes in flow and pressure. The controllers are applied to change the pump output pressure and flow based on the braking mode. Due to the existence of numerous situations for parameters influencing the choice of braking method and the significant difference in the amount of recovery energy in two scenarios an artificial neural network has been employed to decide between single and double braking. To validate the suggested model, a setup for experimentation has been created to simulate various circumstances. Compared to conventional circuits, the modification to the hydraulic circuit increases the initial cost and complexity of the control structure and maintenance. The evaluation of braking performance and the amount of energy stored under various braking conditions resulted to an average energy storage of 63 percent in single braking mode and 17 percent in dual braking mode. The maximum speed error in single braking is 3.5 at 60 RPM and 7 at 132 RPM in double braking. Thus, the maximum speed error during single and double braking is 5.8 and 5.3 percent, respectively. Unlike typical hybrid systems, all braking conditions resulted in the storage of energy.

Automated summary

Environmental contamination has led researchers to propose solutions in various fields, including hybrid drive trains. A new hydraulic circuit for a regenerative braking system is presented to improve energy-saving and eliminate friction braking. The circuit offers single and dual braking modes, with the torque generated by changes in pump output flow and pressure. An artificial neural network is used to decide between the two braking modes. Experimental results show an average energy storage of 63% in single braking mode and 17% in dual braking mode, with maximum speed errors of 3.5 and 7 at different RPMs.