The application of optimal control theory to hybrid electric transit systems. Master's thesis
In an effort to minimize energy losses through the optimal control of an electric rapid transit system, three vehicle/flywheel configurations are modeled using the bond graph technique. Field and armature control of an on-board flywheel are presented along with field control of a station flywheel used in conjunction with a typical regenerative vehicle. Pontryagin's Minimum Principle is used to develop the optimal control trajectories for vehicle accelerations and decelerations. The time integral of mechanical and electrical losses is minimized as the cost function. Armature control of the hybrid vehicle and field control of the station flywheel are equally efficient in the reversible energy flow between vehicle and flywheel. Field control of the hybrid vehicle is slightly less efficient. The optimal trajectory for deceleration is nearly linear, but the optimal trajectory for acceleration, due to the effect of mechanical losses over a longer time period, is highly concave and differs radically from a typical transit acceleration. The vehicle weight and resistance in the armature windings have a large influence on system performance.
- Research Organization:
- Air Force Inst. of Tech., Wright-Patterson AFB, OH (USA)
- OSTI ID:
- 6273092
- Report Number(s):
- AD-A-059365
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
330300* -- Advanced Propulsion Systems-- Electric-Powered Systems
330400 -- Advanced Propulsion Systems-- Hybrid Systems
ACCELERATION
CONTROL SYSTEMS
COST
ELECTRIC-POWERED VEHICLES
ENERGY CONSERVATION
ENERGY LOSSES
ENERGY STORAGE
FLYWHEEL ENERGY STORAGE
HYBRID ELECTRIC-POWERED VEHICLES
LOSSES
MATHEMATICAL MODELS
OPTIMIZATION
PERFORMANCE
STORAGE
VEHICLES