Regenerative Braking in the Case of Hybrid Propulsion Systems

In the case of most hybrid vehicles, electric motors used for traction also allow braking by generating electricity, which is then stored in a traction battery. The paper presents the results obtained on an experimental stand that connects three power sources: a heat engine, an electric motor and a generator. A double-satellite planetary mechanism is the main part of an experimental stand that has been designed for coupling 3 power sources. In this way, the behavior of the transmission of a mixed hybrid car with the division of the power flow is simulated, a solution that simulates a continuously variable transmission with electric control. Starting from a dynamic model of the stand, the differential equations of motion of the mechanical system with two degrees of freedom that couple the three machines are determined. The presented mathematical model, by modeling the external characteristics of the engines, can be used to simulate all the operating regimes of a hybrid car. The experimental results are compared with the theoretical ones obtained by integrating the equations of motion, in order to determine the torque in case of regenerative braking.