Tag Archives | Electrical Engineering

Differential Protection for Power Transformers | Electrical Engineering

The differential protection used for power transformers is based on Merz-Price circulating current principle. Such protection provides protection against internal phase-to-phase and phase-to-earth faults and is generally used for transformers of rating exceeding 2 MVA. This protection system as applied to power transformers is fundamentally the same as that for generators but with certain complicating features not encountered in the [...]

By |2018-03-07T08:16:33+05:30March 7, 2018|Transformer|Comments Off on Differential Protection for Power Transformers | Electrical Engineering

Classification of Circuit Breakers | Devices | Electrical Engineering

There are several methods of classification of circuit breakers. On the basis of type of current they may be classified as ac circuit breakers and dc circuit breakers. AC circuit breakers may be classified on the basis of rated voltages. Circuit breakers below rated voltage of 1,000 V are known as the low-voltage circuit breakers and above 1,000 V are [...]

By |2018-03-07T08:16:33+05:30March 7, 2018|Circuit Breakers|Comments Off on Classification of Circuit Breakers | Devices | Electrical Engineering

Circuit Breakers: Operation and Mounting | Devices | Electrical Engineering

In this article we will discuss about operation and mounting of circuit breaker. Operation of Circuit Breaker: Each circuit breaker is provided with an operating mechanism. The functions of this mechanism are: (i) To close the breaker contacts rapidly without hesitation at all currents from zero to rated making current capacity (ii) To hold the breaker contacts together against the [...]

By |2018-03-07T08:16:33+05:30March 7, 2018|Circuit Breakers|Comments Off on Circuit Breakers: Operation and Mounting | Devices | Electrical Engineering

Vacuum Circuit Breakers: Properties & Applications | Electrical Engineering

In this article we will discuss about:- 1. Construction of Vacuum Circuit Breaker 2. Operating Mechanism of Vacuum Circuit Breaker 3. Contact Materials 4. Properties 5. Applications 6. Advantages 7. Disadvantages. Contents: Construction of Vacuum Circuit Breaker Operating Mechanism of Vacuum Circuit Breaker Contact Materials for Vacuum Circuit Breakers Properties of Vacuum Circuit Breakers Applications of Vacuum Circuit Breakers Advantages [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Vacuum Circuit Breakers|Comments Off on Vacuum Circuit Breakers: Properties & Applications | Electrical Engineering

Types of Oil Circuit Breakers: 3 Types | Electrical Engineering

The following points highlight the three main types of oil circuit breakers. The types are: 1. Plain Break Oil Circuit Breakers 2. Arc Control Oil Circuit Breakers 3. Low Oil or Minimum Oil Circuit Breakers. Type # 1. Plain Break Oil Circuit Breakers: The plain oil circuit breaker is very simple in construction. It consists of current carrying contacts enclosed [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Oil Circuit Breakers|Comments Off on Types of Oil Circuit Breakers: 3 Types | Electrical Engineering

How to Protect Transmission Lines ? | Electrical Engineering

There are several protective schemes for transmission lines and may be grouped into two groups viz., non-unit type and unit type. The non-unit type of protection includes time-graded overcurrent protection, current-graded overcurrent protection, and distance protection, while the unit type protection includes pilot-wire differential protection, carrier-current protection based on phase comparison method etc. Separate protection systems are necessary for ground [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Transmission Lines|Comments Off on How to Protect Transmission Lines ? | Electrical Engineering

Time-Graded Protection of Transmission Lines (Applications) | Electricity

The application of time-graded protection to radial feeders, parallel feeders, and ring main system will be discussed here: Application # 1. Protection of Radial Feeders: The main characteristic of a radial system is that power can flow in one direction only, from generator or supply end to the load end. It has the drawback that continuity of supply cannot be [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Transmission Lines|Comments Off on Time-Graded Protection of Transmission Lines (Applications) | Electricity

Carrier-Current Protection of Transmission Lines | Electrical Engineering

In this article we will discuss about:- 1. Introduction to Carrier-Current Protection 2. Methods of Carrier-Current Protection 3. Advantages. Introduction to Carrier-Current Protection: In modern high-power electrical systems it is necessary to have quick-acting protections on long transmission lines. The requirements to be met by such protections are fully satisfied by the circulating current differential protection with its high sensitivity, [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Transmission Lines|Comments Off on Carrier-Current Protection of Transmission Lines | Electrical Engineering

Bus-Bar Protection of Transmission Lines | Electrical Engineering

The most commonly used schemes for bus-zone protection are: 1. Backup Protection for Bus-Bars 2. Frame Leakage or Fault-Bus Protection 3. Differential Overcurrent Protection. All the protection schemes must also be provided with a check system to ensure that the protection responds only to earth faults occurring within the bus zone and not to extraneous earth faults. 1. Backup Protection [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Transmission Lines|Comments Off on Bus-Bar Protection of Transmission Lines | Electrical Engineering

Summation Transformers: Converting 3-Phase Quantities | Electricity

Summation devices are employed to compare the relaying quantities derived from the currents in the three phases of the primary circuit. The effectiveness of the comparison of the derived relaying quantities may be considered in terms of the effective ratio of the primary currents under comparison, such as at the two ends of a feeder. Summation devices are employed for [...]

By |2018-03-07T08:16:32+05:30March 7, 2018|Transformer|Comments Off on Summation Transformers: Converting 3-Phase Quantities | Electricity
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