Brief discussions about Brushless Exciter and Wound Rotor Motors

System of exciter is planned to manage the voltage that has been applied and also the field current which flows to the rotor that as a result enables the controlling of terminal voltage or generator output. Consequently this results in providing power factor control and reactive power between the system and the generator. Response time of excitation should be quick as such the automatic voltage regulation may be controlled in the generator at the time of system transient or disturbance in which quick alteration of excitation are needed. Brushless exciter includes ac generator having high frequency along with a revolving assembly of fused diode, a transformer power supply and for excitation management a stationary voltage regulator. The Brushless Exciter is usually fixed as an additional feature in respect to generator shaft. Components of rectifier are installed on the assembly of diode wheel, or they are kept sometimes into the shaft. A 3 phase transformer along with the station battery for the purpose supporting initial field flashing and giving support to the sudden fault current, regulator and power.

Wound Rotor Motors are usually utilized for adjustable conditions of speed and high torque. At minimum speeds, either power is reverted back from the circuit of rotor to the grid utilizing various common energy recovery procedures or power is misused in resistances of rotor. At minimum torque and lower speed conditions, the wastage of power within the rotor circuit is very high. Moreover, if method of stator voltage control is utilized it becomes effective in respect of fan kind loads only. For consistent torque loads, the range of speed control as achieved from is highly restricted. A cost effective, efficient, scheme of simple speed control is provided for Wound Rotor Motors. Both rotor resistance management methods and stator voltage management are put together and an optimal condition is observed for controlling the voltage. A thruster’s dependent AC regulator utilized for controlling of stator voltage functions effectively in this situation. Thereafter the resistance of the rotor is controlled for the needs of adjusting the speed. The motors functions smoothly even at low speed conditions and very low torque.