Efficiency of mechanical energy recovery from a tram by different input conditions

At present, more and more traction vehicles use energy recovery while braking. During this recuperation, electric traction motor becomes a generator and kinetic energy with potential energy is converted into electrical energy. Thereby the direction of current turns and electrical energy is returned to the contact line. Efficiency of the energy recovery depends on a number of factors and conditions (braking intensity, quality and a profile of a track, switching losses in transistors, rolling resistance between the wheels and rails, and other). The article deals with the evaluation of some of the factors influencing the success of regenerative process based on real measured data in the tramway service.