## EE2026 POWER SYSTEM DYNAMICS Lecture Notes for EEE - Seventh (7th) semester

EE2026 Lecture Notes

Syllabus:

UNIT I INTRODUCTION
Basics of system dynamics – numerical techniques – introduction to software packages to study the
responses.
Concept and importance of power system stability in the operation and design - distinction between
transient and dynamic stability - complexity of stability problem in large system – necessity for
reduced models - stability of interconnected systems.

UNIT II SYNCHRONOUS MACHINE MODELLING
Synchronous machine - flux linkage equations - Park’s transformation - per unit conversion -
normalizing the equations - equivalent circuit - current space model - flux linkage state space model.
Sub-transient and transient inductances - time constants.
Simplified models (one axis and constant flux linkage) - steady state equations and phasor
diagrams.

UNIT III MACHINE CONTROLLERS
Exciter and voltage regulators - function and types of excitation systems - typical excitation system
configuration - block diagram and state space representation of IEEE type 1 excitation system -
saturation function - stabilizing circuit.
Function of speed governing systems - block diagram and state space representation of IEEE
mechanical hydraulic governor and electrical hydraulic governors for hydro turbines and steam
turbines.

UNIT IV TRANSIENT STABILITY
State equation for multimachine system with one axis model and simulation – modelling of
multimachine power system with one axis machine model including excitation system and speed
governing system and simulation using R-K method of fourth order (Gill’s technique) for transient
stability analysis - power system stabilizer. For all simulations, the algorithm and flow chart have to
be discussed.

UNIT V DYNAMIC STABILITY
System response to small disturbances - linear model of the unregulated synchronous machine and
its modes of oscillation - regulated synchronous machine - distribution of power impact - linearization
of the load equation for the one machine problem – simplified linear model - effect of excitation on
dynamic stability - approximate system representation - supplementary stabilizing signals - dynamic
performance measure - small signal performance measures.