Hydro Generator- Part 3

Out-puts from a Generator - Governors

•

• •Governor ensures frequency at a set value by increasing / decreasing the fuel input
  
  Two types of Governors :
  Pneumatic : Fuel flow is controlled by valve position control. Control Input : DC Voltage

          Electronic : Fuel flow is controlled by a total servo mechanism. Control input : DC Voltage pulses 

 

Out-puts from a Generator - Voltage

• •Voltage is induced in the stator winding
•  Terminal voltage depends upon :

1.   No. of conductors in series per winding
2.   Speed at which magnetic field cuts the winding
3.   Strength of the magnetic field
   

 Voltage Control

• •Nominal Voltage = 415 V, 11 kV 
• Voltage can vary due to load fluctuations 
• Terminal voltage is controlled by

varying the Strength of magnetic field

          = varying the current through the field coil
          = varying the voltage applied to the field coil (Exciter control)

 

Typical Exciter

 

Read more in coming posts... 

Hydro Generator- Part 1

GENERATOR BASICS

Generator Structure

• Generator is a machine which converts Mechanical energy into Electrical energy
• Magnetic Induction Principle
• An emf is induced in a coil whenever
• a coil cuts through a magnetic field
• a magnetic field cuts through a coil
• emf induction is due to relative motion between two parts ( coil & magnetic field)
• Relative motion is by Rotation
• Two mechanical parts :
• Field - Part which produces magnetism (Rotor)
• Armature – part where emf is induced (Stator)

Generator components

• Prime Mover
• Rotor (Exciter)
• Stator

 

Read more in coming posts...