Advantages and technical issues of regenerative brake method at all over the speed range

Abstract

In this paper, the authors propose "regenerative brake notch" method which follows the maximum regenerative brake force according to the vehicle speed. This specially designed brake force reference selected by the train driver aims at saving the kinetic energy which originally would be dissipated by the mechanical brake in the high speed range. By means of the regenerative brake notch, it is able to save much kinetic energy, but the brake section is slightly prolonged. Another drawback of this method is how to inform the starting braking point to the driver, because this brake system does not generate constant regenerative brake force all over the speed range. To cope with this problem, the authors propose the utilization of imaginary train that run along with the real train in combination with the preinstalled train information control system (TICS) to obtain the correct starting braking point and inform to the driver. The running profiles of these trains are compared to obtain the correct starting braking point. By means of this method, only the point to start braking is required and the driver can regulate the brake force in the lower speed range to stop the train at the station. In this paper, the energy saving effect by the regenerative brake notch is compared with the conventional constant deceleration brake notch in terms of running distance, error of the starting braking point and rail adhesion coefficient. Through the calculation study, the energy saving effect and usefulness of the proposed regenerative brake notch is revealed.