Inst ToolsInst ToolsInst Tools
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Search
  • Books
  • Software
  • Projects
  • Process
  • Tools
  • Basics
  • Formula
  • Power Plant
  • Root Cause Analysis
  • Electrical Basics
  • Animation
  • Standards
  • 4-20 mA Course
  • Siemens PLC Course
Reading: What happen When Synchronous Generator loss Excitation
Share
Notification Show More
Font ResizerAa
Inst ToolsInst Tools
Font ResizerAa
  • Courses
  • Design
  • PLC
  • Interview
  • Control System
Search
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Inst Tools > Blog > Electrical Machines > What happen When Synchronous Generator loss Excitation

What happen When Synchronous Generator loss Excitation

Last updated: April 25, 2016 3:15 pm
Editorial Staff
Electrical Machines
No Comments
Share
2 Min Read
SHARE

During normal operation of the Synchronous Generator or Alternator excitation to the rotor is provided by the small DC generator running on the same shaft along with main generator. When synchronous generator delivering power to the grid or load it delivers both real power and reactive power to the system. Reactive power is the magnetizing power which helps to deliver the real power from source to the load and also reactive power helps to improve the voltage of the system. Almost all the loads (except capacitance loads) in the power system draws reactive power from system. Alternators, synchronous condensers and capacitor banks connected in the power systems are the only sources of reactive power.

Real power delivered by the generator (MW output power) is governed by the prime mover and the Reactive power delivered (MVAR output ) is governed by the field excitation. When field excitation to the synchronous generator is lost then synchronous generator operates as induction generator and instead of delivering reactive power it absorbs the reactive power from the system as much as 2 to 4 times the generator’s rated load. However the real power (MW output) delivered by the induction generator will remain almost the same as this is controlled by the prime mover.But loss of generator’s reactive power in the system may cause instability to the system. Also, as alternator is operating as induction generator, high currents are induced in to the rotor teeth and wedges and may damage the rotor of the generator. However large alternators are designed to withstand this induced currents.

Immediate tripping of alternator in the case of loss of excitation is not necessary unless the terminal voltage of the generator falls below desired limit due to voltage collapse. Loss of excitation relay (40G) is used for sensing the loss of excitation.

Don't Miss Our Updates
Be the first to get exclusive content straight to your email.
We promise not to spam you. You can unsubscribe at any time.
Invalid email address
You've successfully subscribed !

Continue Reading

Difference between Induction motor and Synchronous motor
Induction Motor Operating Characteristics
Why Damper windings used in synchronous motors
Transformer Energy Losses & Efficiency
Electrical Machines Objective Questions
DC Motor Applications in Industries
Share This Article
Facebook Whatsapp Whatsapp LinkedIn Copy Link
Share
Leave a Comment

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Stay Connected

128.3kFollowersLike
69.1kFollowersFollow
210kSubscribersSubscribe
38kFollowersFollow

Categories

Explore More

What is a Transformer Tap Changer
Advantages & Disadvantages Induction Motor
Types of Generators
Zigzag Transformers Theory
What is a transformer tap changer?
Advantages and Disadvantages of Squirrel Cage Induction motor
Synchronous Generator Salient Pole vs Non Salient Pole
Losses in a DC Generator

Keep Learning

Importance of Hysteresis Loop

Allen-Bradley VFD

AC Motor Speed Control

Applications of Synchronous Motors

Why rating of Synchronous Generators and Alternators in MVA or KVA

Specific-Conductance-Calibration-Procedure

Types of AC Motors and DC Motors

Questions and Answers on Motors and Generators

100+ Questions and Answers on Motors and Generators

Stepper Motor Construction

Stepper Motor Basics, Types, Modes, Wiring, Questions

Difference Between Squirrel Cage and Slip Ring Motors

Learn More

Control valve performance with varying pressure

Control Valve Performance with Varying Pressure

Function of Racks in PLC System

Function of Racks in PLC – Types of SIEMENS S7-400 PLC Racks

Single Push button to ON and OFF a Bulb using Ladder Logic

Single Push button to ON and OFF a Bulb using Ladder Logic

Flow Switch Symbol

Principle of Flow Switch

DCS Commissioning Steps

DCS Commissioning Steps

Most Frequently Asked Instrumentation Questions

General Instrumentation Questions

Calculate Density and Specific Gravity

Calculate Density and Specific Gravity

What is a Filter Circuit

What is a Filter Circuit ?

Menu

  • About
  • Privacy Policy
  • Copyright

Quick Links

  • Learn PLC
  • Helping Hand
  • Part Time Job

YouTube Subscribe

Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Welcome Back!

Sign in to your account

Username or Email Address
Password

Lost your password?