﻿ Protective Relaying for Power Generation Systems by Donald Reimert

Engineering Book from C.H.I.P.S.

Protective Relaying for Power Generation Systems
by Donald Reimert

Protective Relaying for Power Generation Systems provides both a general overview and in-depth discussion of each topic, making it easy to tailor the material to students' needs.

Features:

• Examines the protection of generators and motors at a level of depth not found in more general texts on the subject
• Offers discussions unavailable elsewhere, such as time decrement generator fault calculations and minimum excitation limit
• Includes steady state and dynamic stability limits
• Discusses protective components in detail, emphasizing potential for damage such as rotor and turbine blade heating
• Presents theoretical discussions along with examples that provide quick how-to information
• Includes Excel® and Mathcad® workbook constructions for performing protection-related calculations including CT saturation analysis and power system swings

Contents

Generator Normal Operations

• The Sample System
• Generator Capability
• Voltage Limitations
• System Limitations
• Generator Capability Variations with Voltage
• Excitation System

Generator Short Circuit Calculations

• Short-Circuit Current Characteristics
• Generator Internal Magnetics
• Generator Magnetic Structures
• Generator Constants
• Fault Current Calculations
• Voltage Regulator
• Practical Shortcuts
• Short Circuit Calculation Example

Generator Differential Relay: 87G

• Ideal Differential Relay
• Practical Considerations
• Percentage Differential Relay
• Relay Characteristics
• Minimum Operating Current Setting
• Slope Setting
• Sample System Differential Relay Settings
• CT Saturation
• Stabilizing Resistor
• Balancing Burden
• Time Delay
• Frequency Response

Backup Fault Protection

• Purpose and Implementation
• Voltage Supervised Overcurrent Relays
• Distance Relays

Generator Ground Fault Protection

• Generator Grounding Considerations
• Methods of Grounding
• Ground Fault Protection

Unbalanced Current Protection

• What is Negative-Sequence Current?
• Effects of Negative-Sequence Current
• Generator Negative-Sequence Capability
• Sources of Negative-Sequence Current
• In-Service (I2)^2t Duty Versus Standards
• Unbalanced Current Protection
• Negative-Sequence Relay Settings

Motoring Protection

• Effects of Motoring
• Protection
• Sequential Trip Logic
• Backup Protection
• Setting Device 32
• Applying Reversed Power Relay on the Sample System

Field Winding Protection

• Field Ground Protection
• Field Overcurrent Protection
• Settings for Field Overcurrent Overvoltage Relays
• Applying Field OC Protection on the Sample System

Overexcitation

• Causes of Overexcitation
• Damage
• V/Hz Limits
• Protection
• Settings
• Differential Relay Response to Overexcitation
• Application of V/Hz Protection on the Sample System

Abnormal Frequency Protection

• Effect on Generator
• Steam Turbines
• Combustion Turbines
• Hydro Generators
• Excitation System
• Protection and Settings

Minimum Excitation Limiter

• Overview of the Minimum Excitation Limiter Application
• Setting Criteria Background
• Setting Criteria
• Steady State and Dynamic Stability Considerations
• Coordination with the LOF Relay
• System Stability Limits
• MEL Protective Characteristic
• MEL Dynamic Performance
• MEL Application on the Sample System

Loss of Synchronism

• Turbine Generator Damage
• Transient Stability
• Out-of-Step Protection
• Classical Swing Impedance Characteristic
• Dynamic Swing Representation
• Dynamic Swing Calculations
• Setting Consideration
• Out-of-Step Relay: Device 78
• Setting Out-of-Step on Sample System

Loss of Field Protection

• System Impact
• Generator Damage
• Loss of Field Protection: Device 40
• Distance Relay Schemes
• Other Causes for LOF Relay Operations
• LOF Relays During System Disturbances
• Special Considerations for Hydro Units
• Application of the LOF on the Sample System

Synchronization Protection

• Damage
• Synchronizing Methods
• Synchronism Check Relays (Device 25)
• Automatic Synchronizer (Device 25A)
• Slow Breaker Protection
• Settings
• Synchronizing Equipment on the Sample System

Accidental Energization Protection

• Generator State at Energization
• Breaker Flashover
• Dynamic Analysis of Three-Phase Energization from Standstill
• Generator Damage
• Turbine Damage
• Energization Protection
• Protection Provided by Native Schemes
• Dedicated Energization Protection
• Applying Energization Protection on the Sample System

Motor Protection

• Motor Characteristics And Representation
• Motor Ratings
• Motor Characteristics
• Motor Applications
• Motor Starting
• Mechanic System Considerations
• Pump Characteristics
• Multifunction Microprocessor Relays
• Transient Current Evaluation
• Special Schemes for Difficult Starts
• Direct Temperature Measurement
• Phase Fault Protection
• Ground Fault Protection
• Phase Unbalanced Protection
• Sample Setting Calculations

Index