Part I: Characteristics of Modern Power Systems. Introduction to the Power System Stability Problem. Part II: Synchronous Machine Theory and Modelling. Synchronous Machine Parameters. Synchronous Machine Representation in Stability Studies. AC Transmission. Power System Loads. Excitation in Stability Studies. Prime Mover and Energy Supply Systems. High-Voltage Direct-Current Transmission. Control of Active Power and Reactive Power. Part III: Small Signal Stability. Transient Stability. Voltage Stability. Subsynchronous Machine Representation in Stability Studies. AC Transmission. Power System Loads. Excitation in Stability Studies. Prime Mover and Energy Supply Systems, High-Voltage Direct-Current Transmission. Control of Active Power and Reactive Power. Part III: Small Signal Stability. Transient Stability. Voltage Stability. Subsynchronous Oscillations. Mid-Term and Long-Term Stability. Methods of Improving System Stability.

Power System Stability and Control

This paper presents a practical design perspective on multivariable feedback control problems. It reviews the basic issue-feedback design in the face of uncertainties-and generalizes known single-input, single-output (SISO) statements and constraints of the design problem to multiinput, multioutput (MIMO) cases. Two major MIMO design approaches are then evaluated in the context of these results.

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Multivariable feedback design: Concepts for a classical/modern synthesis

1 Introduction 2 Electromagnetic Transients 3 Synchronous Machine Modeling 4 Synchronous Machine Control Models 5 Single-Machine Dynamic Models 6 Multimachine Dynamic Models 7 Multimachine Simulation 8 Small-Signal Stability 9 Energy Function Methods Appendix A: Integral Manifolds for Model Bibliography Index

Power System Dynamics and Stability

The phenomena of stability of synchronous machines under small perturbations is explored by examining the case of a single machine connected to an infinite bus through external reactance.

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Concepts of Synchronous Machine Stability as Affected by Excitation Control

This paper presents an analysis of static stability in electric power systems. The study is based on a model consisting of the classical swing equation characterization for generators and constant admittance, PV bus and/or PQ bus load representations which, in general, leads to a semi-explicit (or constrained) system of differential equations. A precise definition of static stability is given and basic concepts of static bifurcation theory are used to show that this definition does include conventional notions of steady-state stability and voltage collapse, but it provides a basis for rigorous analysis. Static bifurcations of the load flow equations are analyzed using the Liapunov-Schmidt reduction and Taylor series expansion of the resulting reduced bifurcation equation. These procedures have been implemented using symbolic computation (in MASYMA). It is shown that static bifurcations of the load flow equations are associated with either divergence-type instability or loss of causality. Causality issues are found to be an important factor in understanding voltage collapse and play a central role in organizing global power system dynamics when loads other than constant admittance are present.

http://www.pages.drexel.edu/~hgk22/papers/Kwatny%20Pasrija%20Bahar%20IEEE%20TCS%2086.pdf

Static bifurcations in electric power networks: Loss of steady-state stability and voltage collapse

The application of series capacitors to compensate long-distance high-voltage transmission lines introduces potential modes of dynamic instability caused by interactions with synchronous machines and turbine-generator shaft torsional resonance. This paper describes the modes of ihstability and analytical methods used to predict the combinations of parameters which may lead to instability. Insight into the phenomena of modal interaction, a factor causing one of the unstable modes, is provided.

Self Excited Torsional Frequency Oscillations with Series Capacitors

A method is described for determining the structure and coefficients of dynamic models of turbogenerators from detailed equivalent circuits of the d-and q-axes of a solid rotor generator. These models are intended for analyses of power system dynamics in cases where it is desirable to have a very accurate representation of the synchronous machine. The models have been used to study power system hunting or dynamic stability, first swing or transient stability, load rejection overvoltages, resynchronization of cross-compound turbine-generator sets, field current and voltage during out-of-step operation, voltage dip and other phenomena associated with machine operation on power systems. The paper reviews some of the experience obtained in system studies and in comparisons between test results and computer simulations.

Dynamic Models of Turbine Generators Derived From Solid Rotor Equivalent Circuits

Long term dynamic response of power systems: An analysis of major disturbances

The ability to calculate the dynamic stability limits of synchronous machines is of increasing importance today as generation and transmission equipment are being applied with higher reactances and correspondingly lower stability margins. This paper describes a digital computer program which enables the rapid computation of dynamic stability limits for a single machine connected to an infinite receiving system through a transmission line. Effects of excitation and prime mover power controls are included making the program a valuable tool for the equipment designer. Typical results illustrate the effect of terminal voltage, transmission line reactance, and machine inertia on the stability limits. The concept of damping ratio as an index to relative stability is discussed and illustrated. Also shown are the effects of neglecting saturation and other second-order effects on the calculation of dynamic stability.

A Digital Computer Program for the Automatic Determination of Dynamic Stability Limits

In the fall of 1963, two extended steady-state stability tests were conducted on a 532 000-kW cross-compound steam turbine-generator at the Will County Station of the Commonwealth Edison Company. These tests followed a series of analytical studies conducted from 1961 through 1963, and aimed at predicting extended steady-state stability limits. In the 1950s, similar tests had been conducted on smaller tandem steam turbine-generators and on hydrogenerators. The subject report is the first documentation of tests conducted on cross-compound turbine-generator sets. In addition, studies and tests were conducted to confirm steady-state stability limits in the generator overexcited region (lagging power factor operation). Operation in this region may occur with extra long transmission lines or weak interconnections between the unit and the power system.

Donald N. Ewart

Papers

Self Excited Torsional Frequency Oscillations with Series Capacitors

Dynamic Models of Turbine Generators Derived From Solid Rotor Equivalent Circuits

Long term dynamic response of power systems: An analysis of major disturbances

A Digital Computer Program for the Automatic Determination of Dynamic Stability Limits

Stability Studies and Tests on a 532-MW Cross-Compound Turbine-Generator Set