Non-Destructive Diagnostic of High Voltage Electrical Systems : Theoretical Analysis and Practical Applications / Josef Vedral.

Format:

Book

Author/Creator:

Vedral, Josef, 1972- author.

Series:

River Publishers series in energy engineering and systems

Language:

English

Subjects (All):

Electric machinery--Testing.

Electric machinery.

High voltages.

Nondestructive testing.

Physical Description:

xxviii, 307pages : illustrations ; 24 cm

Place of Publication:

Gistrup, Denmark : River Publishers, 2023.

Summary:

This book describes the methods of signal processing used in the non-destructive diagnostics of mechanical and electrical properties of high-voltage electrical machines. Traditional and less traditional methods are given, which allow measuring the mechanical and electrical properties of these machines in order to determine their technical condition, including a description of their measurement methods. Separate chapters are devoted to the causes and methods of measuring and evaluating partial discharges arising in the insulation systems of high-voltage electrical machines. The following chapters provide an overview of the test methods used in the non-disassembly diagnostics of high-voltage transformers, rotary machines, high-voltage cables, insulators, surge arresters and circuit breakers. The book is intended for students of technical universities and experts in the field of non- destructive diagnostics of high-voltage electrical machines. The book was reviewed by Ing. Jiří Brázdil, Ph.D. MBA, Head of the HV laboratory of ORGREZ in the Czech Republic.

Contents:

Cover

Half Title

Series Page

Title Page

Copyright Page

Table of Contents

Preface

List of Figures

List of Tables

List of Abbreviations

Chapter 1: Introduction

Chapter 2: General View on Diagnostics of Electrical Machines

2.1: Diagnosed Object

2.2: Online and Offline Diagnostic

2.2.1: Offline diagnostic

2.2.2: Online diagnostic

2.3: Forecast of the Condition of the Diagnosed Device

References

Chapter 3: Diagnostics of Mechanical Parts of HV Machines

3.1: Measuring Machine Vibration

3.1.1: Types of vibrations and vibrodiagnostic quantities

3.1.2: Vibrometer sensors

3.1.2.1: Deflection sensors

3.1.2.2: Speed sensors

3.1.2.3: Acceleration sensors

3.1.3: Analysis of vibrometric signals

3.1.3.1: Analysis of vibrometric signals in the time domain

3.1.3.2: Analysis of vibrometric signals in the frequency domain

3.2: Torsional Oscillation of Shafts

3.2.1: Causes of shaft torsional oscillation

3.2.2: Measurement of shaft torsional oscillation

3.3: Measurement of Temperature Images of Electrical Machines

3.3.1: Contact temperature sensors

3.3.2: Non-contact temperature sensors

Chapter 4: Insulation Systems of HV Electric Machines

4.1: Electrical Properties of Insulators

4.1.1: Electrical strength of insulators

4.1.1.1: Electrical strength of gaseous insulators

4.1.1.2: Electrical strength of liquid insulators

4.1.1.3: Electrical strength of solid insulators

4.1.2: Electrical conductivity of insulators

4.1.2.1: Electrical conductivity of gaseous insulators

4.1.2.2: Electrical conductivity of liquid insulators

4.1.2.3: Electrical conductivity of solid insulators

4.1.3: Polarization of insulators

4.1.4: Dielectric losses in insulators

4.1.4.1: Dielectric losses in gaseous insulators.

4.1.4.2: Dielectric losses in liquid insulators

4.1.4.3: Dielectric losses in solid insulators

4.2: Types of Insulators

4.2.1: Gaseous insulators

4.2.2: Liquid insulators

4.2.3: Solid insulators

4.3: Electrical Stress on Insulators

4.3.1: Stress on plate insulators

4.3.2: Stress on cylindrical insulators

4.4: Degradation of Isolators

4.4.1: Mechanical aging

4.4.2: Thermal aging

4.4.3: Electrical aging

4.4.4: Combined aging

Chapter 5: Measurement of Properties of Insulation Systems of HV Electrical Machines

5.1: Measurement of Insulation Current and Resistance

5.2: Measurement of Capacity and Loss Factor

5.2.1: Measurement of capacity and loss factor by the HV Schering bridge

5.2.2: Measurement of capacitance and loss factor of HV impedance meters

5.2.3: Measurement of frequency dependence of capacity and loss factor

5.3: Measurement of Dielectric Absorption of Insulation Systems

Chapter 6: Partial Discharges in Insulating Systems of HV Electric Machines

6.1: Formation and Types of Partial Discharges

6.2: Partial Discharge Parameters

6.3: Partial Discharge Models

6.3.1: Model of external and surface partial discharges

6.3.2: Gemant-Philippoff model of internal partial discharges

6.3.3: Bönings model of internal partial discharges

6.4: Effect of Partial Discharges on the Insulation Systems of HV Machines

6.4.1: Electro-erosive effects of partial discharges

6.4.2: Chemical effects of partial discharges

6.4.3: Thermal effects of partial discharges

Chapter 7: Measurement and Detection of Partial Discharges

7.1: Electrical Methods Measurement and Detection of Partial Discharges

7.1.1: Properties of partial discharge current pulses

7.1.2: Galvanic methods for measuring partial discharges.

7.1.2.1: Coupling capacitors

7.1.2.2: Coupling impedance

7.1.3: Measurement of partial discharges

7.1.3.1: Measurement of partial discharges with oscilloscope

7.1.3.2: Measurement of partial discharges by a peak detector

7.1.3.3: Partial discharge meters with direct signal digitization

7.1.4: Charge calibration

7.1.5: Measurement of partial discharges by current transformers

7.1.6: Measurement of partial discharges by inductive probes

7.1.7: Measurement of partial discharges by capacitive probes

7.2: Non-electrical Methods for the Detection of Partial Discharges

7.2.1: Ultrasonic detection of partial discharges

7.2.2: High-frequency detection of partial discharges

7.2.3: Optical partial discharges detection

7.2.4: Chemical detection of partial discharges

Chapter 8: Voltage Tests of HV Electric Machines

8.1: DC Voltage Tests

8.2: AC Voltage Tests

8.3: Voltage Tests by Long-term Induced Voltage

8.4: Impulse Voltage Tests

8.4.1: Course of impulse voltage tests

8.4.2: Test pulses

8.4.3: Generation of test voltage pulses

8.4.3.1: Single-stage voltage shock generators

8.4.3.2: Multi-stage voltage shock generators

8.4.4: Voltage level impulse tests

8.4.4.1: Tests with a constant number of voltage levels

8.4.4.2: Up-down tests

8.4.4.3: Phased stress tests

8.4.4.4: Statistical methods for the evaluation of level tests

8.5: Shock Wave Tests

Chapter 9: Diagnostics of Power Transformers

9.1: Types of Power Transformers

9.2: Properties of Transformers

9.3: Diagnostics of Electrical Properties of Power Transformers

9.3.1: Measurement of active winding resistance

9.3.2: Checking the sequence and rotation of the phases

9.3.3: Measurement of transmission, voltage, and no-load losses.

9.3.4: Measurement of short-circuit voltages and losses

9.3.5: Measuring the efficiency of transformers

9.3.6: Measurement of insulation resistance, polarization index, and transformer time constant

9.3.7: Measurement of loss factor and winding capacity

9.3.8: Winding fault detection

9.4: Diagnostics of Transformer Oil Properties

9.4.1: Measurement of electrical properties of transformer oils

9.4.1.1: Measurement of breakdown voltage at mains frequency

9.4.1.2: Measurement of relative permittivity and loss factor

9.4.1.3: Measurement of internal resistivity of transformer oils

9.4.2: Measurement of physical properties of transformer oils

9.4.2.1: Transformer oil color measurement

9.4.2.2: Transformer oil density measurement

9.4.2.3: Measuring the viscosity of transformer oils

9.4.2.4: Measurement of flash and combustion temperatures

9.4.2.5: Freezing temperature measurement

9.4.3: Measurement of chemical properties of transformer oils

9.4.3.1: Water content measurement

9.4.3.2: Oil acid measurement

9.4.3.3: Measurement of the presence of sulfur

9.4.3.4: Content of polycyclic aromatics and polychlorinated biphenyls

9.4.3.5: Gas content measurement

Chapter 10: Diagnostic of Rotary HV Electrical Machines

10.1: Types of HV Rotary Electrical Machines

10.2: Properties of HV Rotary Electrical Machines

10.3: Diagnostics of HV Rotary Electrical Machines

10.3.1: Offline diagnostic of HV rotary electrical machines

10.3.2: Online diagnostic of HV rotary electrical machines

10.3.2.1: Ozone detection measurement

10.3.2.2: Measurement of hydrogen purity in cooling systems of electrical machines

10.3.2.3: Frequency analysis of currents and scattering magnetic fields

10.3.2.4: Measurement of machine noise

10.3.2.5: Online monitoring of partial discharges.

10.3.3: Shaft voltages and currents

10.3.3.1: Generation of shaft voltages and currents

10.3.3.2: Measurement of shaft voltages and currents

10.3.3.3: Means of suppressing shaft voltages and currents

Chapter 11: Diagnostics of HV Power Cables

11.1: Types of MV Power Cables

11.2: Properties of High-voltage Power Cables

11.3: Measurement of Properties of HV Power Cables

11.3.1: Measuring the resistance of cables

11.3.2: Measuring the through resistance of cables

11.3.3: Measurement of cable leakage resistances

11.3.4: Measurement of capacity and loss factor of cables

11.3.5: Measurement of partial discharges in cables

Chapter 12: Diagnostics of Insulators, Surge Arresters, and Circuit Breakers

12.1: HV Insulators

12.1.1: Parameters of HV insulators

12.1.2: Voltage tests of insulators

12.1.2.1: Dry stress tests

12.1.2.2: Wet stress tests

12.2: Preload Arresters

12.2.1: Types of surge arresters

12.2.1.1: Air spark gap

12.2.1.2: Blow arrester

12.2.1.3: Valve lightning arrester

12.2.1.4: Non-sparking preload limiters

12.2.2: Parameters of preload limiters

12.2.3: Voltage tests of voltage arresters

12.2.3.1: Ignition voltage tests

12.2.3.2: Residual voltage measurement

12.2.3.3: Current pulse endurance test

12.2.3.4: Operational functionality tests

12.3: Power Switches and Disconnectors

12.3.1: Diagnostic methods for circuit breakers

List of symbols

List of Constants and Quantities

List of Standards

Index

About the Author.

Notes:

Includes bibliographical references and index.

Description based on print version record.

ISBN:

1-5231-5636-8

1-00-339419-1

1-000-88138-5

1-000-88140-7

1-003-39419-1

87-7022-801-9

9781003394198

OCLC:

1381094647