## Basic Terms in Electrical Machine and their Definition

Manish Kumar Saini

Updated on 30-Sep-2021 08:45:39

In this article, we will take a look at some of the basic terms used in Electrical Machines and their definition.Field WindingThe winding of the electrical machine through which a current is passed to produce the main flux is known as field winding.Armature WindingThe winding of the electrical machine in ... Read More

## Armature Reaction in Alternator at Unity Power Factor Load

Manish Kumar Saini

Updated on 30-Sep-2021 08:37:08

Consider the direction of rotation of the rotor is clockwise. The direction of the generated voltage in various conductors can be determined by applying the right-hand rule keeping in view that the direction of rotation of the conductors with respect to the rotor poles is anticlockwise.Consider the alternator is supplying ... Read More

## Voltage Regulation of Alternator or Synchronous Generator

Manish Kumar Saini

Updated on 25-Sep-2021 07:54:49

The voltage regulation of an alternator or synchronous generator is defined as the rise in the terminal voltage when the load is decreased from full-load rated value to zero. The speed and field current of the alternator remain constant.In other words, the voltage regulation of the alternator can be defined ... Read More

## Armature Reaction in Alternator or Synchronous Generator

Manish Kumar Saini

Updated on 25-Sep-2021 07:37:20

Armature Leakage ReactanceIn an AC electrical machine, the magnetic flux set up by the load current which does not contribute to the useful magnetic flux of the machine is known as leakage flux. This leakage flux sets up a self-induced EMF in the armature winding of the machine. The leakage ... Read More

Manish Kumar Saini

Updated on 25-Sep-2021 07:35:25

Consider a 2-pole alternator as shown in Figure-1. Suppose that the alternator is loaded with an inductive load of zero power factor leading.. Thus, the phase currents πΌπ , πΌπ and πΌπ΅ will be leading their respective phase voltages πΈπ , πΈπ and πΈπ΅ by 90°. Figure-2 shows the phase ... Read More

## Armature Reaction in Alternator at Lagging Power Factor Load

Manish Kumar Saini

Updated on 25-Sep-2021 07:18:51

Consider a 2-pole alternator as shown in Figure-1. Suppose that the alternator is loaded with an inductive load of zero power factor lagging. In this case, the phase current πΌπ , πΌπ and πΌπ΅ will be lagging with their respective phase voltages πΈπ , πΈπ and πΈπ΅ by 90°. The ... Read More

## Advantages of Stationary Armature–Rotating Field Alternator

Manish Kumar Saini

Updated on 25-Sep-2021 07:13:40

Practically, most of the synchronous generators or alternators have stationary armature and rotating field.A stationary armature-rotating field alternator has several advantages over a rotating armature type alternator, as given below −When a stationary armature is used in the alternator, the output current can be taken directly from the fixed terminals ... Read More

## Synchronous Impedance Method (EMF Method) for Finding Voltage Regulation of Alternator

Manish Kumar Saini

Updated on 25-Sep-2021 07:09:27

The synchronous impedance method or EMF method is used to determine the voltage regulation of the larger alternators. The synchronous impedance method is based on the concept of replacing the effect of armature reaction by an imaginary reactance.For an alternator, \mathrm{π½ = π¬_{π} − π°_{π}π_{π} = π¬_{π} − π°_{π}(π_{π} + ... Read More

## Saturated and Unsaturated Synchronous Reactance in Synchronous Generator

Manish Kumar Saini

Updated on 25-Sep-2021 07:01:17

Unsaturated Synchronous ReactanceAt low excitations, the open-circuit characteristic (OCC) of an alternator coincides with the air-gap line, thus, the synchronous impedance of the alternator is constant and this value of the synchronous impedance is known as linear or unsaturated synchronous impedance.The unsaturated synchronous reactance (denoted by Xsu) can be obtained ... Read More

## What is Synchronous Reactance & Synchronous Impedance?

Manish Kumar Saini

Updated on 25-Sep-2021 06:55:58

In an alternator or synchronous generator, the actual generated voltage consists of the summation of two component voltages. One of these component voltages is the excitation voltage  (πΈexc); it is the voltage that would be generated because of the field excitation only. The excitation voltage is the voltage that would ... Read More