Why are current transformers used in power system?
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…
What are the basic requirements of a protection system used in a power network or equipment?
The following are the basic requirements of any power system protection system: ReliabilitySimplicitySelectivitySensitivitySpeed of operationEconomy Circuit breaker
What are the essential components of a protective relay?
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…
What are the main functions of a protection relay?
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…
What is a protection relay?
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…
Which is the most efficient electrical machine?
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…
How rating of a circuit breaker for a system is determined?
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…
Which is the most common fault occuring in the power system?
The most common fault occurring in the power system is a Single line to ground fault. Almost 70 per cent of faults occurring is Single line to ground faults.
What are the different faults occurring in the overhead transmission lines?
What are the different faults occurring in the overhead transmission lines?
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. (more…)