Functional part of Wound Rotor Motors and Brushless Exciter

Wound Rotor Motors are 3 phase induction variants which feature increased torque values, speed control capacity and highly reduced current flow at the time of start up. Squirrel-cage motors or traditional induction are developed to adopt 3 separate windings of wire terminated at 3 slip rings over the motor shaft. At the time of startup, a resistance of variable type is put in series with the windings of rotor through the slip rings those results in lessening of entire current draining and an enhancement in obtainable torque. This permits little type motors to be utilized with high inertia and high slip loads. Machines like fans with large diameter ventilation facility, slurry pumps and long conveyor belts are termed as high slip load or high inertia loads. To mention in other way, owing to their topmost inertia prospect, they need plenty of time to gain operational speeds after starting. If traditional motors take such type of loads, they will have to be able to withstand these torque demands and additional periods of startup current compared to minimum running values. In order to get a suitable solution to the problem, the power supply system, the motor and its starters will have to be more greater than required to operate the machine actually. A substitute to this problem is availing Wound Rotor Motors.

Exciter is combination of devices or a type of device that supplies the magnetic current for generating the flux for working. For its application in industry primarily three kinds of exciters are there and they are utilized in the alternator as Pilot or DC Exciter, Brushless Exciter or Static Exciter. The main functioning of the exciter is to provide the dc voltage excitation to the attached poles inside the generator. Brushless Exciter is an extra generator attaché over the shaft of the prime generator. In case of DC generator, this would supply direct current to the poles via conventional slip ring. In case of exciter the output of AC exciter is modified through rotating type diodes and provides direct current to prime fixed poles. Field winding of AC generator is stationary and its armature rotates.