## Star-Star Connection of Transformer | Three - Phase Transformer Connection

Manish Kumar Saini

Updated on 13-Aug-2021 12:43:39

The star-star connection of transformer is shown in the figure. Here, the one terminal of three windings on each of the primary and the secondary sides being connected at a common point (called neutral point) and the other end of each winding is taken out as the line terminal.In the ... Read More

## Star-Delta Connection of Transformer | Three - Phase Transformer Connection

Manish Kumar Saini

Updated on 13-Aug-2021 12:40:18

In case of the star-delta connection of a transformer, the primary winding of the transformer is connected in star while the secondary winding is connected in delta (see the figure).Primary Winding – Since the primary winding is connected star fashion. Therefore, the primary line voltage is equal to the √3 ... Read More

## Six-Phase Star Connection and Diametrical Connection of Transformers

Manish Kumar Saini

Updated on 13-Aug-2021 12:37:54

The rectifiers are used to convert alternating current (AC) to direct current (DC). The advantages of increased number of phases of the AC supply are given as follows −A smoother waveform is obtained on the DC side as the number of phases of the AC supply is increased.The objectionable harmonics ... Read More

## Short-Circuit Test and Open-Circuit Test on a Three-Winding Transformer

Manish Kumar Saini

Updated on 13-Aug-2021 12:30:01

Short-circuit and open-circuit tests are to be performed on a 3-winding transformer to determine the parameters of the equivalent circuits of it.Short-Circuit TestThe equivalent impedances Z1, Z2 and Z3 referred to a common base can be determined by performing three short-circuit tests as follows −Test 1In the first test, the ... Read More

## What is Potential Transformer (P.T.) and how it works?

Manish Kumar Saini

Updated on 13-Aug-2021 12:19:13

A potential transformer (P.T.) is an instrument transformer which is used for the protection and measurement purposes in the power systems. A potential transformer is mainly used to measure high alternating voltage in a power system.Potential transformers are step-down transformers, i.e., they have many turns in the primary winding while ... Read More

## Parallel Operation of Transformers – Reasons and Conditions

Manish Kumar Saini

Updated on 13-Aug-2021 12:12:53

When the primary windings of two or more transformers are connected to a common voltage supply and their secondary windings are connected to a common load. Then, the transformers are said to be connected in parallel, i.e., parallel operation of the transformers. The figure shows two transformers T1 and T2 ... Read More

## Open Delta Connection or V-V Connection of Transformers

Manish Kumar Saini

Updated on 13-Aug-2021 12:08:13

If one transformer of delta-delta connected transformer bank is damaged or opened, then rest of the system will continue to supply the 3-phase power. If this damaged transformer is isolated, the remaining two transformers will function as a 3-phase bank with rating reduced to about 58 % that of the ... Read More

## Construction and Working Principle of DC Generators

Manish Kumar Saini

Updated on 13-Aug-2021 10:59:36

DC GeneratorA DC generator is an electromechanical energy conversion device that converts mechanical power into DC electrical power through the process of electromagnetic induction.A DC generator operates on the principle of electromagnetic induction i.e. when the magnetic flux linking a conductor changes, an EMF is induced in the conductor. A ... Read More

## DC Motor Voltage Equation, Power Equation and Condition for Maximum Mechanical Power

Manish Kumar Saini

Updated on 13-Aug-2021 10:58:51

DC Motor Voltage EquationConsider a DC shunt motor as shown in the figure.Let, $$\mathrm{V\:=\:Applied\:DC\:voltage}$$$$\mathrm{E_{b}\:=\:Back\:EMF}$$$$\mathrm{R-{a} \:=\:Resistance\:of\:the\:armature\:circuit}$$$$\mathrm{I_{a}\:=\:Armature\:current}$$By applying the KVL in the armature circuit, we get, $$\mathrm{V\:=\:E_{b}\:+\:I_{a}R_{a} … (1)}$$The expression in eqn. (1) is known as the voltage equation of the DC motor.Power Equation of DC MotorIf the eqn. (1) is multiplied ... Read More

## Construction and Working Principle of DC Motors

Manish Kumar Saini

Updated on 13-Aug-2021 10:56:59

A DC motor is an electromechanical energy conversion device, which converts electrical energy input into the mechanical energy output.The operation of the DC motor is based on the principle that when a current carrying conductor is placed in a magnetic field, a mechanical force acts on the conductor. The magnitude ... Read More