Department of Electrical and Electronics Engineering

Power System Dynamics
Unit - 1
SYNCHRONOUS MACHINE MODELLING
Schematic Diagram, Physical Description: armature and field structure, machines withmultiple pole pairs, mmf waveforms, direct and quadrature axes, MathematicalDescription of a Synchronous Machine: Basic equations of a synchronous machine:stator circuit equations, stator self, stator mutual and stator to rotor mutual inductances,dq0 Transformation: flux linkage and voltage equations for stator and rotor in dq0coordinates, electrical power and torque, physical interpretation of dq0 transformation,Per Unit Representations: Lad-reciprocal per unit system and that from power-invariantform of Parks transformation; Equivalent Circuits for direct and quadrature axes, Steady-state Analysis: Voltage, current and flux-linkage relationships, Phasor representation,Rotor angle, Steady-state equivalent circuit, Computation of steady-state values,Equations of Motion: Swing Equation, calculation of inertia constant, Representation insystem studies, Synchronous Machine Representation in Stability Studies:Simplifications for large-scale studies : Neglect of stator p? terms and speedvariations, Simplified model with amortisseurs neglected:two-axis model withamortisseur windings neglected, classical model.
Unit - 2
MODELLING OF EXCITATION AND SPEED GOVERNING SYSTEMS
Excitation System Requirements; Elements of an Excitation System; Types of ExcitationSystem;Control and protective functions;IEEE (1992) block diagram for simulation ofexcitation systems. Turbine and Governing System Modelling: Functional Block Diagramof Power Generation and Control, Schematic of a hydroelectric plant, classical transferfunction of a hydraulic turbine (no derivation), special characteristic of hydraulic turbine,electrical analogue of hydraulic turbine, Governor for Hydraulic Turbine: Requirement fora transient droop, Block diagram of governor with transient droop compensation, Steamturbine modelling: Single reheat tandem compounded type only and IEEE block diagramfor dynamic simulation; generic speed-governing system model for normal speed/loadcontrol function.
Unit - 3
SMALL-SIGNAL STABILITY ANALYSIS WITHOUT CONTROLLERS
Classification of Stability, Basic Concepts and Definitions: Rotor angle stability, TheStability Phenomena. Fundamental Concepts of Stability of Dynamic Systems: State-space representation, stability of dynamic system, Linearisation, Eigen properties of thestate matrix: Eigen values and eigenvectors, modal matrices, eigen value and stability,mode shape and participation factor. Single-Machine Infinite Bus (SMIB) Configuration:Classical Machine Model stability analysis with numerical example, Effects of FieldCircuit Dynamics: synchronous machine, network and linearised system equations,block diagram representation with K-constants; expression for K-constants (noderivation), effect of field flux variation on system stability: analysis with numericalexample,
Unit - 4
SMALL-SIGNAL STABILITY ANALYSIS WITH CONTROLLERS
Effects Of Excitation System: Equations with definitions of appropriate K-constants andsimple thyristor excitation system and AVR, block diagram with the excitation system,analysis of effect of AVR on synchronizing and damping components using a numericalexample, Power System Stabiliser: Block diagram with AVR and PSS, Illustration ofprinciple of PSS application with numerical example, Block diagram of PSS withdescription, system state matrix including PSS, analysis of stability with numerical aexample. Multi-Machine Configuration: Equations in a common reference frame,equations in individual machine rotor coordinates, illustration of formation of system statematrix for a two-machine system with classical models for synchronous machines,illustration of stability analysis using a numerical example. Principle behind small-signalstability improvement methods: delta-omega and delta P-omega stabilizers.
Unit - 5
ENHANCEMENT OF SMALL SIGNAL STABILITY
Power System Stabilizer Stabilizer based on shaft speed signal (delta omega) DeltaP-Omega stabilizer-Frequency-based stabilizers Digital Stabilizer Excitation controldesign Exciter gain Phase lead compensation Stabilizing signal washout stabilizergain Stabilizer limits