| Breaking energy hasn't been well used by now, and the recovering of the breaking energy is potential especially for city bus and subway vehicle, which need to start and break frequently. Many ways are used to recover the breaking energy, such as the hydraulic way, flywheel and the electrochemical way. The electrochemical way is the most promising one, and it is reliable, easy to operate, and has a simple structure and higher recover rate of the breaking energy. It is widely used in the newly developed electrical vehicles or hybrid electric vehicles.Along with the development of the technology, the super capacitor is developed. This new kind of electrical component has more than ten times of the power density and one hundred times of charge and discharge velocity than the storage battery. The breaking energy can be recovered and then released quickly with the super capacitor.A novel breaking energy recovery system, which takes the super capacitor as the energy store device, is presented here. The general questions in breaking energy recovery are discussed, and the dynamic models of the subway and the electrical vehicle are presented. The energy of the vehicle that can be recovered in different initial speed and ending speed is calculated from the simulation based on Simulink, and the reference of the capacity of the super capacitor is calculated.The characters of the super capacitor, the transfer rules of the DC/DC converter, the breaking characters of the vehicle and the characters of the DC machine, which are associated with breaking energy store system droved by the DC machine, are introduced here, and with these rules the mathematic model and the control rule of DC/DC convertor are obtained. At last, with the two toolboxes Simulink and SimPowerSystems in Matlab the simulation models and the simulation results of the subway vehicles and the electric vehicles are presented, also a detailed analysis of the simulation results are given.
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