Losses in a transformer | Types | Classification of losses in transformer

Classification of Transformer losses

There are mainly two types of losses in transformer. They are:

1. Core losses or Iron losses and
   1. Hysteresis loss and
   2. Eddy current loss
2. Copper losses

Apart from these two types there are other losses are present in

Compensating Winding in DC Machines

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Function of Compensating winding

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The compensating winding are used in DC machines to neutralize the cross magnetizing effect of armature reaction.

These are generally used only large machines which are subjected to large fluctuations due to

Instantaneous value

Instantaneous value of a time varying wave form

The value of a time varying quantity such as alternating current is not constant and varies with respect to time. The value of such a quantity at an instant of time is called

Circuit breaker

Description of Circuit Breaker

Circuit breaker is a protective device used in power system to protect the system on the event of fault. It isolates the faulty part of the power system in case of the any abnormal conditions. The circuit breaker functions along with a relay which senses

Voltage Source

A voltage source is an active element in electrical circuits which delivers voltage to the circuit. An ideal voltage source should have no internal resistance (or Impedance in AC) and its output voltage is independent of the current passing through the element. The voltage delivered by an ideal voltage source is always

EMF Equation of a DC Generator

Generator EMF Equation

The generator works on the principle of Faraday's laws of electromagnetic induction. When a conductor cuts the magnetic lines of flux e.m.f. (electro motive force) is induced in it. This emf

Commutator

Commutator is used in DC Machines. In DC Generators it facilitates the collection of current from the armature conductors to an external c

Yoke in an electrical machine

The outer frame of an electrical machine either motor or a generator is called yoke.

The yoke provide two functions. First is providing the mechanical support and protection cover to the machine assembly. The second is it provides low reluctance path to carry the magnetic flux. The below figure show the diagram of an electrical machine with the location of Yoke, poles and rotor.

Electrical Machine diagram showing Yoke and the Poles

Yoke is generally made of cast steel or rolled steel for large electrical machines whereas for small machines cast iron may be used.

Resistors in series

When resistors are connected in series, the amount of the current passing through all the resistors will be same but the voltage drops across the resistors may vary. For series connected resistors their resistance adds up. Their equivalent resistance is equal to the sum of all the resistors in series. Thus for a series connection, equivalent resistance increases with increase in number of resistors.

Consider the following circuit of three resistors

Accuracy

In measurements accuracy is defined as the closeness with which the measured value obtained by a measuring instrument is nearer to the true value of the measuring quantity.

Resistors in parallel

When resistors are connected in parallel, the amount of the voltage drop across all the resistors is same but the current passing though the resistors varies depending on their resistance values. For parallel connected resistors the equivalent resistance is equal to inverse of the sum of inverse resistances in parallel. Thus for a parallel connection of resistors, equivalent resistance decreases with increase in number of resistors in parallel.

Consider the following

Precision

Precision is a measure of reproducibility of measurements. Most repeated value or most reproduced value is called as precise value.

Precision never confirms accuracy.

If the measuring

Transformer

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Transformer is a static device or a machine that transfers electrical energy from one electrical circuit to another through medium of magnetic field without change in frequency. It is an electromagnetic energy conversion device and can raise or lower the voltage with a corresponding decrease or increase in current. A transformer consists of two conducting coils (or windings) having a mutual inductance. These coils are wound on a laminated core made of high permeability magnetic material. The coil which receives electrical energy from supply terminals is called

Voltage

Description

The electric potential difference between two points is called voltage. The voltage is equal to the work done per unit charge to move a test charge between two points against static electric field.

Electric potential is given by

Electrical Resistance

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The property of a material that reduces the flow of current through it is called electrical resistance. Every material will have some amount of resistance except super conductors which have zero resistance. The materials which have very low resistance are called conductors. The inverse of resistance is called conductance.  Resistors are used to control the amount of current passing through conductors. But they dissipate the energy in

Electric Conductors

The material which allows the flow of electrical current are called electric conductors. Generally metals are good conductors of electricity and metals such as copper and aluminum are the most commonly used.

In conductors the electrons are the charge carriers. The electrons move freely from