Thesis Presentation Power Point Presentation

8/3/2019 Thesis Presentation Power Point Presentation

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Microcomputer Based Methodology

for Distance Protection on Long UHVTransmission Lines Using

Symmetrical Components

Presented by: Mashood Nasir

Advisor: Dr.Aziz BhattiStudent Id No. 091450-024


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Problem Statement Protection scheme as a key element of a power system

Microprocessor based approach for distance protection

Intelligent fault diagnostic

sophisticated control

Effective fault clearing

Economical


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Importance of problem and keyfunctions

Pragmatic and pessimistic approach

Digital protection scheme

Fault detection

Location

Faulty phase selection

Isolation Re closure


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Contribution to the Field

Single performance equation

Greatly Simplified

Potentially Faster

Efficiency

reliability


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Symmetrical Components Theory

Positive Sequence Components

Negative Sequence Components

Zero Sequence Components


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Sample Network


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Proposed Methodology

Voltage Ratios & Their Applications

Ko = Eo /Eo

K1 = E1 /1

K2

= E2

/E2

Kl = Z11 I1 /E1

Fault Location

Faulty Phase Identification

Fault Classification


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Sequence Networks

Three Phase FaultOnly positive sequence circuit exists

Applying boundary conditions: E1 (W) = 0

and solving yields: K = (K1 / 1+ Kl) + r


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Line to Line Fault

Positive and Negative Sequence Circuits are connected in parallel.

Applying Boundary Conditions: E1W = E2W E1 = -E2

Yields: K = (K1 + K2 / 2 + Kl) + r


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Line to Ground Fault

All three (Positive, negative and zero) sequence circuits are connected inseries

Boundary Conditions: E1w+E2w+E0w = 0 , E1=E2


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Yields: Ko Faulty phase judgment

For a-g

K = (K1+K2+Ko.Eo /E1) / (2 + Kl +Eo /E1) + r

For b-g

K = (K1+K2+Ko.Eo / E1) / (2 + Kl +Eo / E1) + r

For c-g

K = (K1+K2+Ko.Eo / E1) / (2 + Kl +Eo / E1) + r

Ko = l Eo /E1 l e j(o1-11)


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Double Line to Ground FaultAll three (Positive, negative and zero) sequence circuits are connected in Parallel

Boundary Conditions: Eow = E1w = E2w

Yields: K = (K1+Ko.Ko / 1+Ko+Kl) + r


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Compact Single PerformanceEquation

K1 + K2.K2+ Ko.Ko

K = + r

1+Ko+ K2+ Kl


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K- Calculation

Flow Chart


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Settings for Tolerance Values

1 is set by the ratio of lE2 /E1 l and classify whether its a doublephase to ground fault or not.

2 is set by the ratio of lEO /E1 l and distinguish between phaseand ground faults.

3is classify whether its a double phase to ground fault or not.


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Conclusion

Accuracy.

Eliminates the need of multi impedance calculating units.

Phase and fault classification.

Specially suited for digital computers.

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Thesis Presentation Power Point Presentation