Archive for the ‘Electrical distribution’ Category

MV busbar schemes (Review)

March 5th, 2018 | 1 Comment | Posted in Electrical distribution

megaphone-blueChoosing a good bus scheme is vital for operational reliability, safety and redundancy of power supply system.

Your fellow electrical engineer K. tries to discuss busbar layout and busbar schemes as per the design of a typical substation.

Introduction

Busbar(s) consist of incoming and outgoing circuits with a common point. Every circuit connected to a busbar scheme has its separate incomer, circuit breaker, isolator, potential transformer, current ratio transformer and associated switchgear. These components are arranged in a special sequence so as to trip a specific circuit in case of an abnormality.
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Fuse failure supervision (supervision functions)

February 19th, 2018 | 1 Comment | Posted in Electrical distribution

Ahmed H. wanted to tell us about Supervision functions- especially Fuse failure supervision. Enjoy!

fuse failure supervision

What is fuse failure supervision?

Fuse-failure supervision is a function used to supervise the operation of the fuses responsible for protecting the secondary circuit of the potential transformer, which delivers the reduced voltage to the protection relay and voltmeters.

In relay codes and substation automation, the fuse-failure supervision function can be identified by the following symbols,
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Current and auto transformers (working principle)

February 12th, 2018 | 1 Comment | Posted in Electrical distribution

As we know transformers are device for converting one AC voltage to the another AC voltage with same frequency. One transformer is made of core, primary windings and secondary windings.

In general there are two main classes voltage and power transformers. Let Milan – one of the members of the Electrical Engineering Community Blog tell us about it.

Principle of one classic transformer

Picture 1. Principle of one classic transformer

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Sympathetic tripping in electrical power systems

February 9th, 2018 | 2 Comments | Posted in Electrical distribution

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New article by Carlos who sometimes sends us his essays. If you too want to be published in the blog, do not hesitate to send us a mail.

Introduction

Several industries and utilities have experienced circuit breakers tripping due to undesirable relay operations, producing blackouts and a decrease in their expected incomes. This situation has raised a lot of concern in managers, grid operators, and reliability and protection engineers who have carried out root cause analysis to determine the origin of the missoperation of the protection systems.
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AC aircraft brushless generators with constant speed drive unit

February 6th, 2018 | 1 Comment | Posted in Electrical distribution

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As Milan talked earlier, aircraft generators are essential part of aircraft electrical system. Briefly, he mentioned two main types of AC generators, one is constant frequency and another is variable frequency generators.

Now, he’s going to dive deeply in working principle of one most common generator – brushless generator.

Standard generators are bitten from brushless

Classic use of brushes and slip rings for passing excitation current to AC windings made huge problems due to brush consumption and during the time rotating surface make traces on rotor of generator. Also, power that is conveyed is smaller that in brushless type.
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