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**Voltage Regulation Of Synchronous Machines [Alternator] By Direct Loading Test**

#### Today in this post we are going to learn what is **Voltage regulation of synchronous machine** and different methods to calculate V**oltage regulation of synchronous machine.**

__The definition of Voltage regulation of a synchronous machine:__

__The definition of Voltage regulation of a synchronous machine:__

**Voltage Regulation of synchronous machine** is defined as the difference between the terminal voltage at no load and terminal voltage at full load and excitation, speed must remain same.**Voltage Regulation of synchronous machine **is generally calculated in percentage of full load terminal voltage.

__Objectives for calculating Voltage regulation of a synchronous machine:__

__Objectives for calculating Voltage regulation of a synchronous machine:__

#### 1. Parallel operation of alternators is affected by the voltage regulation. By calculating **voltage regulation of synchronous machine** we can adjust the parallel operating machines to be in synchronism.

#### 2. Calculating **voltage regulation of a synchronous machine** determines the type of automatic voltage control equipment required for resisting the voltage changes.

#### 3.When the load is thrown off voltage rise must be known because with the rise in voltage the insulation must be able to withstand this rise.

#### So the calculation of **voltage regulation of synchronous machine** has a great importance.

__The general expression for calculating Voltage regulation of synchronous machine:__

__The general expression for calculating Voltage regulation of synchronous machine:__

#### Now let us derive the general expression for calculating **voltage regulation of a synchronous machine**

#### Let E be the terminal voltage of the synchronous machine at no load. Now if the synchronous machine is given full load the terminal voltage will no longer be E because of the losses so let the terminal voltage now be V.

#### So general expression for Voltage regulation of a synchronous machine is given by

#### Voltage regulation% = (E – V / V) × 100

__Methods for calculating voltage regulation of synchronous machine:__

__Methods for calculating voltage regulation of synchronous machine:__

#### There are two types of methods for calculating **voltage regulation of synchronous machine.**

#### 1. Direct load test method.

#### 2. Indirect Method.

#### The indirect method of calculating **voltage regulation of synchronous machine** can be further classified into 3 types:

#### 1.EMF method or Synchronous impedance method.

#### 2. MMF method or Ampere turn method.

#### 3.Zero power factor method or Potier method.

__Direct load test method for calculating voltage regulation of synchronous machine:__

__Direct load test method for calculating voltage regulation of synchronous machine:__

#### Now let’s see how to calculate **voltage regulation of synchronous machine** by using direct load test method:

**Circuit diagram for calculating Voltage regulation of synchronous machine by direct load test:**