Reactors

REACTORS

A coil or other component which provides reactance in a circuit . A series reactor is an inductive coil connected in a circuit or system to limit the short circuit current .the circuit breakers in the system are selected so that they can interrupt the maximum short circuit current in the system. 

A series reactor may be fixed aur switched type. A  fixed reactor is permanently connected in the circuit. 

Types of Reactors - 

Reactors are used in now days are mostly air cored coils . They are built in types -

1.Dry type reactor:- 

Dry-type reactors are mainly employed in electric power transmission and distribution systems as well as in electric power systems of electrical plants. They are installed to protect these systems and to increase their efficiency.

2.Oil immersed reactor :

It is mainly used in principal part of the electric force and distribution system in large power plant, nuclear power plant, and hydropower station. An oil immersed reactor has a smaller in size for (the same reading )the higher thermal capacity and fewer chances of flash over as compared to the dry type. Oil immersed reactors are built for both outdoor and indoor use and for all system voltages.

#Reactor Locations :-

1. Generator reactor -  it is connected in series with alternator.Modern alternators have high inherent reactance and therefore do not need any external reactor for limiting the current. However they are still used for some old machines.

2.Feeder Reactor :- Reactor is connected in series with each feeder. Since the number of feeders is generally large, this connection entails the use of a large number of reactors. Since the reactors carry full load current, a constant power loss occurs.

3.Bus Bar Reactor :-  During normal operations only a small power flows through the reactor and hence very small power loss takes place.the contribution of fault current by other generators is limited by reactors.

4.Tie Bus Bar Reactor :- This scheme has the advantage that the the fault current is is independent of the number of generators connected in the system.