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Ministry of Science and TechnologyYangon Technological University

Department of Electrical Power Engineering

Ministry of Science and TechnologyYangon Technological University

Department of Electrical Power Engineering

Analysis of Power System Stability for

Industrial Zone

Second Seminar

( 26.12.2012 )

Supervised by Presented by

Dr. Wint Wint Kyaw Mg Soe Thura Nyein

Ph.D EP -2

Ph.D (Engineering ) 6th Batch

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Aims and ObjectivesAims and Objectives

• To analyze the industrial power system stability and optimize the networks costs

• To increase of power supply quality up to developed countries level

• To construct and plan the own industrial network design

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Outline of PresentationOutline of Presentation

• Introduction

• Requirement of Smart Industrial Zone

• Transient Stability

• Feeder Position of Actual Industrial Zone

• Ideal Industrial Zone

• Planning Standards

• Analytical Frameworks

• Further Study

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Types of security violations & consequencesTypes of security violations & consequences

Security

OverloadSecurity

VoltageSecurity

Dynamic Security

Xfmr overload

Lineoverload

Low Voltage

Unstable Voltage

Early-swing

instability

Oscillatory instability (damping)

Large-disturbance instability

Small-disturbance instability

Fast voltage collapse

Slow voltage collapse

Cascading overloads

Overloaded X’mer/line has higher tripping likelihood,

resulting in loss of another element, possible

cascading, voltage or dynamic insecurity

Low voltage affects load and generation operation. Voltage

instability can result in widespread loss

of load.

Dynamic security can result in loss of generation;

growing oscillations can cause large power swings to enter relay trip zones

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Requirements of a Smart Industrial ZoneRequirements of a Smart Industrial Zone

Software and supportProfessional tools for professional work

Power system studies and optimizationExcellent planning leads to excellent results

Asset management solutionsKnowing exactly where to act

Transient StabilityTransient Stability

Transient Stability• Each generator operates at the same synchronous

speed and frequency of 50 hertz while a delicate balance between the input mechanical power and output electrical power is maintained.

• The ability of power system to survive the transition following a large disturbance and reach an acceptable operating condition is called transient stability.

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Classification of Types of Stability Classification of Types of Stability

Long-Term Stability

Mid-Term Stability

Short-Term or Transient Stability

Range of Time Periods

0 to 10 seconds

10 seconds to Few Minutes

Few Minutes to Several Minutes

Transient Stability LevellingTransient Stability Levelling

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Transmission network connected generators

– high fault levels

– high inertia

– high-speed protection

high transient stability

low transient stability

Distribution network connected generators

– low fault levels

– low inertia

– slow-speed protection

Hlaing Thar Yar Industrial Zone (Actual)Hlaing Thar Yar Industrial Zone (Actual)

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Hlaing Thar Yar IZ Allowable 50 MVA

Hlaing Thar Yar S/S (100 MVA)

Hlawga S/S(280 MVA)

33 kV, 300 A (each)

33 kV, 300 A (each)

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Industrial systemsIndustrial systems

• Motor behavior

• System protection

• Transient analysis

• Harmonic analysis

• Filter design

• Energy efficiency

• etc

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Amp and Time Curve for a Line Amp and Time Curve for a Line 1:

00

2:00

3:00

4:00

5:00

6:00

7:00

8:00

9:00

10:0

0

11:0

0

12:0

0

13:0

0

14:0

0

15:0

0

16:0

0

17:0

0

18:0

0

19:0

0

20:0

0

21:0

0

22:0

0

23:0

0

0:00

050

100150200250300350400450500

Daily Load Cycle of Hlaing Thar Yar Line

Daily Load Cycle

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Power System Operation StatesPower System Operation States

Normal

Restorative Alert

In-extremis Emergency

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Ideal Industrial ZoneIdeal Industrial Zone

Ideal IZ Allowable 50 MVA up to Back-up withstand

From Electricity Supply

From Back-up Supply

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Planning StandardsPlanning Standards

Four major topics are:

• System Adequacy and Security• System Modeling Data Requirements • System Protection and Control• System Restoration

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System Modeling Data RequirementsSystem Modeling Data Requirements

• System Data• Generation Equipment• Facility Ratings• Actual and Forecast Demands• Demand Characteristics (Dynamic)

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System Restoration System Restoration

System Black Start Capabilitythe necessary to establish initial generation

that can be supply electric power to other system generation to handle the supply to the auxiliaries in the power plant, the coal handling equipment etc.

Automatic Restoration of Load the automatic load restoration plan would

require careful analysis of the setting of relays used to restore load automatically, sequence in which tie lines etc.

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Analytical FrameworksAnalytical Frameworks

• Power Flow Analysis– Partial PV and QV curves can be readily

calculated using power flow programs.

• Continuation Methods– A popular and robust technique to obtain full PV

and/or QV curves is the continuation method.

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continuedcontinued

• Optimization or Direct Methods– The maximum loading point can be directly

computed using optimization-based methodologies.

• Time Scale Decomposition– The PV and QV relations produced results

corresponding to an end state of the system where all tap changers and control actions have taken place in time and the load characteristics were restored to a constant power characteristic.

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Mitigation of VoltageMitigation of Voltage

• From Fault to Trip– To understand the various ways of mitigation, the

mechanism leading to an equipment trip needs to be understood.

• Reducing the Number of Faults– Reducing the number of short-circuit faults in a

system not only reduces the sag frequency, but also the frequency of long interruptions.

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Continued:Continued:

• Reducing the Fault-Clearing Time– Reducing the fault-clearing time does not reduce

the number of events, but only their severity.

• Changing the Power System– Install a generator near the sensitive load.

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Further Study Further Study

To analyze: • The Balance Fault and • Unbalance Fault.

Some types of fault apply to my ideal IZ– Single Line to Ground fault– Double Line to Ground fault– Line to Line fault– Three Phase fault

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ReferencesReferences

• NERC Planning Standards, http://www.nerc.com/standards/

• Vijay Vittal, 2002, Consequence and Impact of Electric Utility Industry Restructuring on Transient Stability.

• Prabha Shankar Kundur, 1994, Power System Stability and Control from Power System Engineering Series.

• Mansour, Y., editor , 1990. Voltage Stability of Power Systems: Concepts, Analytical Tools, and Industry Experience, IEEE Special Publication #90TH0358–2-PWR.

• Goran Andersson, 2010, Dynamics and Control of Electric Power Systems.

• Leonard L. Grigsgy, 2008, Electric Power Engineering Handbook: Power System Stability and Control, pp 470-482.

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Thanks for Your Attention