Correct Answer - Option 2 : Reactors are used
Current Limiting Reactor:
- It is also known as a Fault limiting reactor.
- The current limiting reactor is an inductive coil having large inductive reactances in comparison to their resistance.
- It is used for limiting short circuit currents during fault conditions.
- Current-voltage reactors also reduced the voltage disturbances on the rest of the system.
- It is installed in feeders and ties, in generators leads, and between bus sections.
- Therefore used for reducing the magnitude of short circuit currents and the effect of the respective voltage disturbance.
- The current reactor allows free interchange of power under normal conditions.
- But when the fault occurs the disturbance is restricted by the current reactor to the faulty section.
- As the resistance of the system is very small as compared to their reactance. Hence, the efficiency of the system is not much affected.
Functions of Current Limiting Reactor:
-
The current limiting reactor reduces the flow of short circuit current so as to protect the appliances from mechanical stress and overheating.
-
The current reactor reduced the magnitude of voltage disturbances which is caused by short circuits.
Therefore they protect the circuit breakers which have an inadequate rating
-
It limits the fault current to flow into the healthy feeders or parts of the system, thereby avoiding the fault from spreading.
This increases the chances of continuity of supply.
Drawbacks of the current limiting reactor:
- When the reactor is installed on the network, the total percentage reactance of the circuit increases.
- It decreases the power factor and thus the regulation becomes poorer.
