Dissertations and Theses

Date of Award


Document Type




First Advisor

Ahmed Mohamed


Regenerative Braking Recuperation Energy Management


In a city that never sleeps, NYC, also called the big apple, there is the largest population in the United States with close to 9 million people. In addition, it is the second wealthiest city in the world according to ranking by gross domestic product (GDP). Being such a densely populated city, people cannot only rely on their vehicles as the only source of commute. The alternative is to use mass transit. New York City Transit (NYCT) is the largest mass transit system that offers commuting services via subway or buses. More than half of the population rely on mass transit as their daily form of transportation, with subway stations accounting for most of the ratio. This means that trains must be constantly running to carry passengers to their destinations.

For this to happen, the utility grid must supply all the required power to maintain a healthy subway operation. However, not all this power is efficiently utilized by the train load. There are power losses that happen from the grid to its path to the train. The train gets power from a line on the track called the “third rail”. From one station A to another station B, the train typically undergoes several phases: acceleration, cruising, and deceleration. During acceleration from station A energy is drawn from the third rail, but when the train is approaching station B it could potentially reproduce some regenerative braking energy and send it back to the third rail. However, sue to operational limits, most of this energy is typically dissipates as heat.

One method of recuperating this energy is by implementing a regenerative braking technology. This works by converting the kinetic energy that keeps the train in motion to electrical energy and saving them in storage devices for use later. The result of this conversion is that the train brakes in a more energy efficient way as less heat is dissipated, which leads to both energy savings and peak demand reduction.



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