The working principle of the self-excited DC generator in series is that the magnetic field coil is connected in series with the armature winding and the output of the generator, so this type of generator is called DC generator. serial coil excitation current The magnetic field that flows through the magnetic field coil of this generator is It is the same as the current that the generator supplies to the load, so we make the output voltage depend on the current flowing through the load.
The mixed DC generator is to bring the advantages of the generator. Direct current in parallel and in series are combined into one device, becoming a hybrid generator. This is an even better feature. Types of DC generators can be divided according to the circuit connection characteristics of the coil. A magnetic field has two characteristics:
The stator steel core is the part used to wind the armature coil. The stator steel core is made of thin steel sheet. stacked by reason to design The stator steel core to look like this It is to reduce losses due to hysteresis (Hysteresis Loss) or the loss of magnetic lines created by the coil. with eddy currents in the steel core (Eddy Current Loss) and the steel core also It is a thin soft iron which contains silicon compounds. When they are stacked together, they are made possible. Steel core with greater strength In addition, each steel plate has grooves. air for cooling There are 3 types of stator core grooves which are
A rotating float with a winding embedded around the rotor axis. by the rotor will produce from a dense silicon sheet with an insulating barrier In order to create a eddy current which the electric current is obtained from the exciter, the rotor can be divided into two types.
Salient – Pole Type rotor is used in low speed generators. or medium-speed generators such as generators that use upstream power as water turbines of various dams
Smooth (Cylindrical Type) rotors are used in generators powered by turbine or gas turbines with high rotational speeds of approximately 1,500 rpm and 3,000 rpm. The rotor is a sheet of steel sheet stacked in a long cylinder shape. They are smaller in diameter than the standing pole rotor. The smooth pole rotor is more balanced than the extended pole type and reduces power loss. because of the friction of the wind and centrifugal force to escape the center while rotating is driven at the speed itself
Damper coil will look like a copper bar which is embedded at the surface area The face of the rotating magnetic pole They are short-circuited to the copper rings on both sides of the rotor. The damper windings prevent vibration or oscillation when the generator speed is uneven.
