Advanced Locomotive Energy Storage System

At present, trains use various dissipative braking systems to slow and stop, and this significant braking energy is ultimately converted to heat and wasted. APEI, Inc. has proposed a hybrid tender which can capture and reuse a significant fraction of this braking energy (at least 50%). The hybrid tender draws power from the rails using a regenerative braking technique rather than by being electrically connected to a diesel generator. Energy absorbed in this manner (while the train is slowing and stopping) can later be used to accelerate the train. This hybrid tender consists of dedicated traction motors, power electronics converters, a battery energy storage system, thermal management systems, electronic control and communication systems, and other auxiliary systems as needed. This system will improve fuel economy significantly, reduce emissions, reduce the US reliance on foreign oil, and can also improve speed regulation of the train. By drawing power from the rails, the proposed hybrid tender can be used in conjunction with any existing locomotive with no major modifications or retrofitting. Such a system can be widely adopted in the near future. The existing locomotive fleet (-20,000 units) presents a major market opportunity and potential for broad environment and economic impacts.