Energy Harvesting Systems to Power Onboard Railroad Equipment

A practical and innovative solution to answer the need for power in freight cars is presented. The lack of available electric power in the vast majority of freight cars limits the use of electronic devices such as measuring (sensor) systems, GPS tracking devices or active RFID tags. An energy harvesting system has been developed to keep a battery charged and electric equipment running. The basic idea is to generate power using the relative motion of the car suspension as an input, scavenging energy that is normally wasted as heat in the damping system. Based on a promising first generation unit used as a proof of concept, the current prototype is designed to fit inside a typical suspension spring (D5) and so, can easily be implemented in virtually any rail car. During laboratory tests, the system is capable of efficiently generating up to 80W of power, on quasi-continuous basis, with a sinusoidal input of 3/8 inch at 2Hz. Durability tests have also been conducted to ensure that the system can withstand the harsh railroad environment. Additionally, actual suspension displacement measurements have been used to replicate real conditions and forge a more precise idea of the behavior that can be expected once implemented in a rail car. With encouraging laboratory tests, the next steps are to further validate the system and to confirm the obtained results with field testing.