RBF Neural Network

Approach For

Security Assessment And

Enhancement

Yesuratnam Guduri Professor, Dept. of Electrical Engg.

University College of Engineering

Osmania University, Hyderabad, India

1

Points to be Addressed • Security Assessment

Static Security Assessment o Static Security Index

Transient Security Assessment o Transient Security Index

• Security Enhancement Static Security Enhancement

o Generation Rescheduling

Transient Security Enhancement o Fast Valving

• RBFNN Approach • Case Studies • Results and Discussion

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Static Security Index

(SSI) Class/ Level of Static Security

SSI = 0 Class A : Secure

SSI > 0 & SSI < = 5 Class B : Critically Secure

SSI > 5 & SSI < = 15 Class C : Insecure

SSI > 15 Class D : Highly Insecure

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STATIC SECURITY ASSESSMENT Ability of a power system to reach a steady state

operating point without violating the system operating

constraints following a contingency

TRANSIENT SECURITY

ASSESSMENT Following the occurrence of a large

disturbance, the system oscillations, if

proceed in opposite directions, will cause

loss of synchronism among generators.

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Angle Stability Transient Security

Index (TSI)

Stable 1

Unstable 0

RBFNN APPROACH

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Power System Operating

state as observed at a

control centre

Static Security Assessment

Transient Security Assessment

INSECURE

Security

Enhancement

Using

Generation

Rescheduling

SECURE

INSECURE Security

Enhancement

using

Fast Valving

Input Features For SSA INPUTS IEEE 14 BUS IEEE 39 BUS

Load bus voltages 9 29

Load bus angles 9 29

Line MVA Flows 20 46

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Input Features For TSA INPUTS 14 BUS

Mechanical power input of generator 5

Voltage behind transient reactance 5

Relative rotor angles at instant of fault application 4

Relative rotor angles at instant of fault clearance 4

Generation Rescheduling –

Static Security Enhancement CCV - Amount of generation to be changed at

each generator in order to relieve the

overload

Fast Valving-

Transient Security Enhancement

CCV - Amount of decrease in the mechanical

power required at each generator to

make the system stable for every fault.

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Results of

Static Security Assessment IEEE 14 bus IEEE 39 bus

Operating scenarios 60 133

Static secure cases 47 22 Static critically

secure cases 10 103

Static insecure 3 8

Training samples 50 110

Testing samples 10 23

8

Security Enhancement

using Generation Rescheduling

IEEE 39 bus

system

Total number of samples 111

Training samples 90

Testing samples 21

Corrective Control Vectors 13

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Results of Transient Security

Assessment

IEEE 14 bus system

Operating scenarios 75

Transient secure 36

Transient insecure 39

Training samples 65

Testing samples 10

10

Security Enhancement using

Fast Valving

IEEE 14 bus system

Total number of samples 39

Training samples 33

Testing samples 6

Corrective control vectors 4

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CONCLUSIONS

Simpler network configurations

Faster training procedures

Suitable for on-line evaluation.

Bring the insecure state to secure

state

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