What is a switchgear
Switchgear is a device which is used for the switching controlling and for the protection of the electrical circuits and equipment, the importance of electricity in our modern civilization is very high so in order to get a continuous power we must secure the power system from large faults and we must protect machinery and devices and thus we can ensure maximum continuity of the power supply
What are the essential features which are needed for switchgear
Complete reliability
Due to the heavy requirement of electricity in our modern world the number of generating stations is also high and so the fault occurring in the power station will be high too and to prevent these faults we need to depend on switchgear so when a fault occurs switchgear can isolate the faulty system and the continuous power will be generated and supplied without any interruption
Absolutely certain discrimination
If any fault occurs in a power system the switchgear must have the ability to discriminate between the faulty section and the healthy section, it must isolate the faulty section without any damage to the health system so that it won’t affect the continuity of the power supply
Quick operation
When a fault occurs in a power system the switchgear must act quickly so that it won’t damage any equipment like the generators and transformers, at the time of fault occurrence the switchgear must act quick and isolate the faulted system from the healthy, if the fault is not cleared it will affect the healthy parts and thus endangering of the complete shutdown will happen
Manual control provision
In some cases, there will be electrical or electronic control fail so in order to protect the power system the necessary operation must be carried out through the manual control, so switchgear must have provision for manual control
Provision for instruments
Instruments provision are needed, it may be in the form of ammeter or voltmeter in the unit itself or necessary current and voltage transformers for connecting to the main switchboard or a separate panel
What are the roles that switchgear plays for the protection of a power system
The major role of switchgear in a power system is to ensure the safe operation of the power system, and by that, we can ensure the people safety too. So by ensuring the safe operation to the power system, it will also ensure the equipment protection and the personnel who works in there.
Many dangerous situations will arise from overcurrents and overvoltages, by the occurrence of earth faults it could cause high touch voltages and it will endanger people, so in order to continue the safe operation of the power system the overcurrent and overvoltage must be prevented
Reliability and stability
The protection system must take care for the reliable operation of the relays so that the reliability can be improved, reliable functions can be referred to as backup protection, reliability can be reached by combining different protection principles example distance and differential protection of transmission lines
Stability of the system is the quality of the system by which the system remains stable and inoperative and stable under certain conditions
Requirement adequateness
There could be many faults and disturbances in a power system so it is impossible to provide protection against each and every fault or abnormal condition due to economic reasons. Instead of that, the system must provide adequate protection
Simplicity
A protection system should be simple so that it could be easily operated and maintained