Conventional eddy current braking is limited in effectiveness to only the high vehicular speed\nregion. As the vehicle slows, the conventional eddy current brake loses effectiveness. This\ninherent drawback is due to the use of static/stationary magnetic field in the brake system. This\nstudy presents a solution - the use of rotating magnetic field in the brake system. By the study\ndesign, the conducting brake disc rotates between the poles of an electromagnet. A constant airgap\nseparates the disc from the poles on either side. The electromagnet windings (each with a\ncore) are made poly-phase so that when an equivalent poly-phase source supplies ac to the\nelectromagnet windings, a rotating magnetic field is obtained. The rotating magnetic field comes on\nwhen the brake is applied and eddy current is induced in the conducting brake disc to effectuate\nretardation. The brake disc is coupled to the road wheel so that retardation of the brake disc\ntransmits directly to the road wheel. The eddy current braking torque is a measure of the braking\npower. The braking torque varies directly as the relative speed between the conducting brake disc and the eddy current brake magnetic field. The braking torque is studied under three main\nconditions. These are when the brake disc and the magnetic field rotate in opposite directions,\nwhen the brake disc and the magnetic field rotate in the same direction and when the wheel is\nstationary with only the magnetic field rotating. Braking performance is studied in terms of stopping\na vehicle, slowing and preventing motion. Results show that stopping and slowing are achieved\nwhen the magnetic field rotates opposite the direction of the brake disc rotation. For stationary\nwheel, motion will not occur as long as the torque which tends to be tractive is counterbalanced by\nfriction at the wheels and the vehicular mass inertia. Modeling and simulation in this study are done\nusing Mat Lab ââ?¬â?? Simulink software.
Loading....