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Why are current transformers used in power system? Protective relays coils and measuring instruments such as an ammeter, watt meter and energy meter are very sensitive devices and cannot be directly connected to the line carrying high magnitudes of current. So, we have to reduce the magnitude to a lower value and equivalent to the … Read more
The following are the basic requirements of any power system protection system: Reliability Simplicity Selectivity Sensitivity Speed of operation Economy
What are the essential components of a protective relay? The essential components of a protective relay are the following: 1. Sensing element. 2. Comparison element. 3. Control element Related searches: What is a protection relay? Protection relay What is the purpose of protection relay? Why is protective relay used? Relays Why relays are used … Read more
What are the main functions of a protection relay? The main functions of a protective relay are the following: · Detection of the presence of a fault. · Detection of presence location of a fault. · Detection of presence type of fault. · To close the trip circuit and operate the circuit breaker to isolate … Read more
What is a protection relay? Protection relay is an electrical device used to sense an abnormal condition in a power system and operate a circuit breaker or an alarm signal. Related searches: What is a protection relay? Protection relay What is the purpose of protection relay? Why is protective … Read more
The most efficient electrical machine is the transformer. Transformers have efficiency above 95%. The autotransformer has an efficiency of close to 98%. The maximum efficiency is achieved under the fully loaded condition. Read More about Transformer: Electric Transformer
How rating of a circuit breaker for a system is determined? The rating of a circuit breaker for a system is determined based on the balanced three phase fault occurring in it. Even though the three phase faults are quite rare, it imposes the most severe duty on the circuit breaker. Hence for any … Read more
1. Single line to ground fault.
2. Line to line fault.
3. Double line to ground fault.
4. Line to line to line fault (Three phases are short-circuited)
5. Three line to ground fault.
