Single phase synchronous alternator working principle
From the point of basic electromagnetic circumstance, a dc motor can be working for motor operation in principle, can also be used as a generator to run, are only different constrained conditions. On the two brush end of the dc motor, and dc voltage, input power to the armature, mechanical energy output from the motor shaft, drag the production machinery, become motor converts electrical energy into mechanical energy, such as prime mover drag dc motor armature, and without dc voltage on the brush, the brush end dc electromotive force can be drawn as dc power, output power, motor become generator converts mechanical energy into electrical energy. The same machine, which can be used as an electric motor or as a generator, is called the reversible principle in the theory of electric motors
Without dc voltage on the brush, constant speed by prime mover drag the armature to counterclockwise rotation, on both sides of the coil is cutting lines of magnetic force under different magnetic polarity, respectively, in which the induction electromotive force, electromotive force direction determined by the right-hand rule. This electromagnetic situation is shown on the graph. Due to the armature rotate continuously, and, therefore, must take the current carrying conductor in magnetic field from the coil side ab and CD alternately cutting lines under the N pole and S pole, although each side of coil and the coil in the direction of induction electromotive force is alternating. Induction electromotive force in the coil is A kind of alternating electromotive force, and in the brush. A, B side electromotive force for dc electromotive force (some say exactly, is A kind of direction invariable pulse vibration electromotive force). Because, the armature in the rotation process, no matter the armature turn to what position, due to the effect of the reversing of the commutator with brush, brush A by commutator segment of electromotive force always is the cutting edge of electromotive force by the coil in N pole magnetic field lines, therefore, brush A always have A positive polarity. In the same way, the brush B has always negative polarity, so the brush can lead to the same change in the direction of the pulse. If the number of coils per pole increases, the pulse vibration decreases, and the dc electromotive force can be obtained. That's how the dc generator works. It also shows that the zidc generator is essentially an ac generator with a commutator.
The working principle of the dc generator is the armature coil alternating during induction electromotive force, the commutator with brush commutation function, make it from the brush end into the principle of dc electromotive force.
