Intelligent power management of a supercapacitor based hybrid power train for light-rail vehicles and city busses

This paper presents the concept of a double-layer capacitor (supercapacitor) based hybrid power train for light-rail vehicles and city busses. The components of the power system are build-up around a common DC-bus. To minimize volume, weight and costs of the power train, the buck-boost inverter is integrated into the traction inverter of the induction machine. The supercapacitor battery is connected by an external inductor. Main element of the hybrid drive is its control, which guarantees a save vehicle operation and manages the power of the hybrid power train. In case of a diesel-electric vehicle the most important aim of the developed control is to save energy by an optimised use of the prime mover unit and by receiving the braking energy by the supercapacitor battery. The stored energy will then be used for the next accelerating phase. This paper presents simulations of the hybrid power train and first practical test-bench results which have been recorded from a prototype inverter made for integration into a diesel-electric bus.