ProtoDrive: An Experimental Platform for Electric Vehicle Energy Scheduling and Control
William Price, Harsh Jain, Yash Pant, Mark Gallagher, Rahul Mangharam
When you want to drive from Philadelphia to New York City, Google or Garmin maps will tell you the distance and time. While this is sufficient information for your conventional vehicle, if you are driving an electric vehicle you need to know the total energy required for the journey. Vehicles involved in urban commutes are subjected to highly variable loads as they traverse varying gradients and stop-and-go traffic. Electric Vehicles can achieve a high efficiency under these conditions due to their ability to recover energy during braking. However, the high current loads during both charging and discharging cause battery energy losses, making them less efficient and degrading their useful lifetime. Super capacitors work well under high power charge and discharge cycles, however, their high cost and low energy density prevent them from being a viable replacement for batteries. A hybrid system consisting of a battery and a super capacitor has the potential to offer the benefits of both devices, which may increase vehicle range and battery lifetime. Consequently, the goal of the project is to:
(a) investigate the use of a hybrid battery/super capacitor system in response to real commuter drive cycles.
(b) develop scheduling algorithms that optimize the flow of energy between the battery, super capacitor and motor.
To this effect, we are developing a low cost, small-scale electric vehicle platform called Protodrive which is capable of simulating a drive cycle in hardware, while remaining small enough to fit on a lab desk. It consists of a physical model of an electric vehicle powertrain (motor, controller, battery, super capacitor) coupled to an active dynamometer, making it possible to run the powertrain through its full speed and torque range. Electronic control of the platform enables consistent testing conditions and fair comparison between battery and hybrid systems, and simulation in hardware will capture elements of the real system that may be missed in an idealized software model.
Project blog – http://protodrive.blogspot.com/2012/04/demo-day.html