Trains and Streetcars
Traction drives are subject to heavy stress as a result of harsh environments, constant temperature variation and change of operating state (starting, high speed, braking, standstill). This places high demands on the quality of the key technology: power semiconductors. They ensure efficient use of energy in the changing operating states by virtue of their robustness and optimal switching properties. During braking, for example, they see to it that the braking energy is returned to the supply system. This operation was calculated from the standpoint of energy efficiency by the Berlin Transportation Company (BVG) for their rail vehicles and they arrived at an energy saving of 20 to 30 percent.