A controlled dynamic braking of a separate excitation DC machine

摘要

This paper aims at demonstrating that a separate excitation for a DC machine can have its dynamic braking optimized via a significant reduction of its elapsed time. Dynamic braking is accomplished when a DC motor is led to operate as DC generator. Its kinetic energy is almost totally converted into electric energy. This energy is dissipated on a resistor connected to the machine armature. The machine field circuit is fed by a battery set via a chopper, produces an excitation current capable of making the e.m.f. constant, until the machine field current reaches its maximum value. After this, the e.m.f decreases, and therefore the braking current is also decreased. Thus, much more energy can be dissipated per unity of time in such an interval. In being so, the necessary time for braking is substantially lesser. Other variables such as braking current, and speed are also analyzed. It is possible to conclude that the machine and its load have not been subjected to any kind of abnormalities or even prohibitive efforts. An industrial application of the project is presented.