PART Ⅰ GENERAL BACKGROUND

1 GENERAL CHARACTERISTICS OF MODERN POWER SYSTEMS

1.1 Evolution of electric power systems

1.2 Structure of the power system

1.3 Power system control

1.4 Design and operating criteria for stability

References

2 INTRODUCTION TO THE POWER SYSTEM STABILITY PROBLEM

2.1 Basic concepts and definitions

2.1.1 Rotor angle stability

2.1.2 Voltage stability and voltage collapse

2.1.3 Mid-term and long-term stability

2.2 Classification of stability

2.3 Historical review of stability problems

References

PART Ⅲ EQUIPMENT CHARACTERISTICS AND MODELLING

3 SYNCHRONOUS MACHINE THEORY AND MODELLING

3.1 Physical description

3.1.1 Armature and field structure

3.1.2 Machines with multiple pole pairs

3.1.3 MMF waveforms

3.1.4 Direct and quadrature axes

3.2 Mathematical description of a synchronous machine

3.2.1 Review of magnetic circuit equations

3.2.2 Basic equations of a synchronous machine

3.3 The dq0 transformation

3.4 Per unit representation

3.4.1 Per unit system for the stator quantities

3.4.2 Per unit stator voltage equations

3.4.3 Per unit rotor voltage equations

3.4.4 Stator flux linkage equations

3.4.5 Rotor flux linkage equations

3.4.6 Per unit system for the rotor

3.4.7 Per unit power and torque

3.4.8 Alternative per unit systems and transformations

3.4.9 Summary of per unit equations

3.5 Equivalent circuits for direct and quadrature axes

3.6 Steady-state analysis

3.6.1 Voltage,current,and flux linkage relationships

3.6.2 Phasor representation

3.6.3 Rotor angle

3.6.4 Steady-state equivalent circuit

3.6.5 Procedure for computing steady-state values

3.7 Electrical transient performance characteristics

3.7.1 Short-circuit current in a simple RL circuit

3.7.2 Three-phase short-circuit at the terminals of a synchronous machine

3.7.3 Elimination of dc offset in short-circuit current

3.8 Magnetic saturation

3.8.1 Open-circuit and short-circuit characteristics

3.8.2 Representation of saturation in stability studies

3.8.3 Improved modelling of saturation

3.9 Equations of motion

3.9.1 Review of mechanics of motion

3.9.2 Swing equation

3.9.3 Mechanical starting time

3.9.4 Calculation of inertia constant

3.9.5 Representation in system studies

References

4 SYNCHRONOUS MACHINE PARAMETERS

4.1 Operational parameters

4.2 Standard parameters

4.3 Frequency-response characteristics

4.4 Determination of synchronous machine parameters

References

5 SYNCHRONOUS MACHINE REPRESENTATION IN STABILITY STUDIES

5.1 Simplifications essential for large-scale studies

5.1.1 Neglect of stator pψ terms

5.1.2 Neglecting the effect of speed variations on stator voltages

5.2 Simplified model with amortisseurs neglected

5.3 Constant flux linkage model

5.3.1 Classical model

5.3.2 Constant flux linkage model including the effects of subtransient circuits

5.3.3 Summary of simple models for different time frames

5.4 Reactive capability limits

5.4.1 Reactive capability curves

5.4.2 V curves and compounding curves

References

6 AC TRANSMISSION

6.1 Transmission lines

6.1.1 Electrical characteristics

6.1.2 Performance equations

6.1.3 Natural or surge impedance loading

6.1.4 Equivalent circuit of a transmission line

6.1.5 Typical parameters

6.1.6 Performance requirements of power transmission lines

6.1.7 Voltage and current profile under no-load

6.1.8 Voltage-power characteristics

6.1.9 Power transfer and stability considerations

6.1.10 Effect of line loss on V-P and Q-P characteristics

6.1.11 Thermal limits

6.1.12 Loadability characteristics

6.2 Transformers

6.2.1 Representation of two-winding transformers

6.2.2 Representation of three-winding transformers

6.2.3 Phase-shifting transformers

6.3 Transfer of power between active sources

6.4 Power-flow analysis

6.4.1 Network equations

6.4.2 Gauss-Seidel method

6.4.3 Newton-Raphson（N-R）method

6.4.4 Fast decoupled load-flow（FDLF）methods

6.4.5 Comparison of the power-flow solution methods

6.4.6 Sparsity-oriented triangular factorization

6.4.7 Network reduction

References

7 POWER SYSTEM LOADS

7.1 Basic load-modelling concepts

7.1.1 Static load models

7.1.2 Dynamic load models

7.2 Modelling of induction motors

7.2.1 Equations of an induction machine

7.2.2 Steady-state characteristics

7.2.3 Alternative rotor constructions

7.2.4 Representation of saturation

7.2.5 Per unit representation

7.2.6 Representation in stability studies

7.3 Synchronous motor model

7.4 Acquisition of load-model parameters

7.4.1 Measurement-based approach

7.4.2 Component-based approach

7.4.3 Sample load characteristics

References

8 EXCITATION SYSTEMS

8.1 Excitation system requirements

8.2 Elements of an excitation system

8.3 Types of excitation systems

8.3.1 DC excitation systems

8.3.2 AC excitation systems

8.3.3 Static excitation systems

8.3.4 Recent developments and future trends

8.4 Dynamic performance measures

8.4.1 Le??ge-signal Performance measures

8.4.2 Small-signal performance measures

8.5 Control and protective functions

8.5.1 AC and DC regulators

8.5.2 Excitation system stabilizing circuits

8.5.3 Power system stabilizer（PSS）

8.5.4 Load compensation

8.5.5 Underexcitation limiter

8.5.6 Overexcitation limiter

8.5.7 Volts-per hertz limiter and protection

8.5.8 Field-shorting circuits

8.6 Modelling of excitation systems

8.6.1 Per unit system

8.6.2 Modelling of excitation system components

8.6.3 Modelling of complete excitation systems

8.6.4 Field testing for model development and verification

References

9 PRIME MOVERS AND ENERGY SUPPLY SYSTEMS

9.1 Hydraulic turbines and governing systems

9.1.1 Hydraulic turbine transfer function

9.1.2 Nonlinear turbine model assuming inelastic water column

9.1.3 Governors for hydraulic turbines

9.1.4 Detailed hydraulic system model

9.1.5 Guidelines for modelling hydraulic turbines

9.2 Steam turbines and governing systems

9.2.1 Modelling of steam turbines

9.2.2 Steam turbine controls

9.2.3 Steam turbine off-frequency capability

9.3 Thermal energy systems

9.3.1 Fossil-fuelled energy systems

9.3.2 Nuclear-based energy systems

9.3.3 Modelling of thermal energy systems

References

10 HIGH-VOLTAGE DIRECT-CURRENT TRANSMISSION

10.1 HVDC system configurations and components

10.1.1 Classification of HVDC links

10.1.2 Components of HVDC transmission system

10.2 Converter theory and performance equations

10.2.1 Valve characteristics

10.2.2 Converter circuits

10.2.3 Converter transformer rating

10.2.4 Multiple-bridge converters

10.3 Abnormal operation

10.3.1 Arc-back（backfire）

10.3.2 Commutation failure

10.4 Control of HVDC systems

10.4.1 Basic principles of control

10.4.2 Control implementation

10.4.3 Converter firing-control systems

10.4.4 Valve blocking and bypassing

10.4.5 Starting, stopping, and power-flow reversal

10.4.6 Controls for enhancement of ac system performance

10.5 Harmonics and filters

10.5.1 AC side harmonics

10.5.2 DC side hermonics

10.6 Influence of ac system strength on ac/dc system interaction

10.6.1 Short-circuit ratio

10.6.2 Reactive power and ac system strength

10.6.3 Problems with low ESCR systems

10.6.4 Solutions to problems associated with weak systems

10.6.5 Effective inertia constant

10.6.6 Forced commutation

10.7 Responses to dc and ac system faults

10.7.1 DC line faults

10.7.2 Converter faults

10.7.3 AC system faults

10.8 Multiterminal HVDC systems

10.8.1 MIDC network configurations

10.8.2 Control of MTDC systems

10.9 Modelling of HVDC systems

10.9.1 Representation for power-flow solution

10.9.2 Per unit system for dc quantities

10.9.3 Representation for stability studies

References

11 CONTROL OF ACTIVE POWER AND REACTIVE POWER

11.1 Active power and frequency control

11.1.1 Fundamentals of speed governing

11.1.2 Control of generating unit power output

11.1.3 Composite regulating characteristic of power systems

11.1.4 Response rates of turbine-governing systems

11.1.5 Fundamentals of automatic generation control

11.1.6 Implementation of AGC

11.1.7 Underfrequency load shedding

11.2 Reactive power and voltage control

11.2.1 Production and absorption of reactive power

11.2.2 Methods of voltage control

11.2.3 Shunt reactors

11.2.4 Shunt capacitors

11.2.5 Series capacitors

11.2.6 Synchronous condensers

11.2.7 Static var systems

11.2.8 Principles of transmission system compensation

11.2.9 Modelling of reactive compensating devices

11.2.10 Application of tap-changing transformers to transmission systems

11.2.11 Distribution system voltage regulation

11.2.12 Modelling of transformer ULTC control systems

11.3 Power-flow analysis procedures

11.3.1 Prefault power flows

11.3.2 Postfault power flows

References

PART Ⅲ SYSTEM STABILITY:physical aspects,analysis,and improvement

12 SMALL-SIGNAL STABILITY

12.1 Fundamental concepts of stability of dynamic systems

12.1.1 State-space representation

12.1.2 Stability of a dynamic system

12.1.3 Linearization

12.1.4 Analysis of stability

12.2 Eigenproperties of the state matrix

12.2.1 Eigenvalues

12.2.2 Eigenvectors

12.2.3 Modal matrices

12.2.4 Free motion of a dynamic system

12.2.5 Mode shape,sensitivity,and participation factor

12.2.6 Controllability and observability

12.2.7 The concept of complex frequency

12.2.8 Relationship between eigenproperties and transfer functions

12.2.9 Computation of eigenvalues

12.3 Small-signal stability of a single-machine infinite bus system

12.3.1 Generator represented by the classical model

12.3.2 Effects of synchronous machine field circuit dynamics

12.4 Effects of excitation system

12.5 Power system stabilizer

12.6 System state matrix with amortisseurs

12.7 Small-signal stability of multimachine systems

12.8 Special techniques for analysis of very large systems

12.9 Characteristics of small-signal stability problems

References

13 TRANSIENT STABILITY

13.1 An elementary view of transient stability

13.2 Numerical integration methods

13.2.1 Euler method

13.2.2 Modified Euler method

13.2.3 Runge-Kutta（R-K）methods

13.2.4 Numerical stability of explicit integration methods

13.2.5 Implicit integration methods

13.3 Simulation of power system dynamic response

13.3.1 Structure of the power system model

13.3.2 Synchronous machine representation

13.3.3 Excitation system representation

13.3.4 Transmission network and load representation

13.3.5 Overall system equations

13.3.6 Solution of overall system equations

13.4 Analysis of unbalanced faults

13.4.1 Introduction to symmetrical components

13.4.2 Sequence impedances of synchronous machines

13.4.3 Sequence impedances of transmission lines

13.4.4 Sequence impedances of transformers

13.4.5 Simulation of different types of faults

13.4.6 Representation of open-conductor conditions

13.5 Performance of protective relaying

13.5.1 Transmission line protection

13.5.2 Fault-clearing times

13.5.3 Relaying quantities during swings

13.5.4 Evaluation of distance relay performance during swings

13.5.5 Prevention of tripping during transient conditions

13.5.6 Automatic line reclosing

13.5.7 Generator out-of-step protection

13.5.8 Loss-of-excitation protection

13.6 Case study of transient stability of a large system

13.7 Direct method of transient stability analysis

13.7.1 Description of the transient energy function approach

13.7.2 Analysis of practical power systems

13.7.3 Limitations of the direct methods

References

14 VOLTAGE STABILITY

14.1 Basic concepts related to voltage stability

14.1.1 Transmission system characteristics

14.1.2 Generator characteristics

14.1.3 Load characteristics

14.1.4 Characteristics of reactive compensating devices

14.2 Voltage collapse

14.2.1 Typical scenario of voltage collapse

14.2.2 General characterization based on actual incidents

14.2.3 Classification of voltage stability

14.3 Voltage stability analysis

14.3.1 Modelling requirements

14.3.2 Dynamic analysis

14.3.3 Static analysis

14.3.4 Determination of shortest distance to instability

14.3.5 The continuation power-flow analysis

14.4 Prevention of voltage collapse

14.4.1 System design measures

14.4.2 System-operating measures

References

15 SUBSYNCHRONOUS OSCILLATIONS

15.1 Turbine-generator torsional characteristics

15.1.1 Shaft system model

15.1.2 Torsional natural frequencies and mode shapes

15.2 Torsional interaction with power system controls

15.2.1 Interaction with generator excitation controls

15.2.2 Interaction with speed governors

15.2.3 Interaction with nearby dc converters

15.3 Subsynchronous resonance

15.3.1 Characteristics of series capacitor-compensated transmission systems

15.3.2 Self-excitation due to induction generator effect

15.3.3 Torsional interaction resulting in SSR

15.3.4 Analytical methods

15.3.5 Countermeasures to SSR problems

15.4 Impact of network-switching disturbances

15.5 Torsional interaction between closely coupled units

15.6 Hydro generator torsional characteristics

References

16 MID-TERM AND LONG-TERM STABILITY

16.1 Nature of system response to severs upsets

16.2 Distinction between mid-term and long-term stability

16.3 Power plant response during severe upsets

16.3.1 Thermal power plants

16.3.2 Hydro power plants

16.4 Simulation of long-term dynamic response

16.4.1 Purpose of long-term dynamic simulations

16.4.2 Modelling requirements

16.4.3 Numerical integration techniques

16.5 Case studies of severe system upsets

16.5.1 Case study involving an overgenerated island

16.5.2 Case study involving an undergenerated island

References

17 METHODS OF IMPROVING STABILITY

17.1 Transient stability enhancement

17.1.1 High-speed fault clearing

17.1.2 Reduction of transmission system reactance

17.1.3 Regulated shunt compensation

17.1.4 Dynamic braking

17.1.5 Reactor switching

17.1.6 Independent-pole operation of circuit breakers

17.1.7 Single-pole switching

17.1.8 Steam turbine fast-valving

17.1.9 Generator tripping

17.1.10 Controlled system separation and load shedding

17.1.11 High-speed excitation systems

17.1.12 Discontinuous excitation control

17.1.13 Control of HVDC transmission links

17.2 Small-signal stability enhancement

17.2.1 Power system stabilizers

17.2.2 Supplementary control of static var compensators

17.2.3 Supplementary control of HVDC transmission links

References

INDEX