Utility Design to Eliminate Voltage Collapse

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Utility Design to Eliminate Voltage Collapse

• Presented by
• Jason Taylor

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Abstract

• Define causes of voltage collapse
• Develop system limitation parameters for system
• Develop cost optimization

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Motivation

• Interest in utility system design
• Potential Hot Spot of activity

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Voltage Collapse

• Voltage collapse is the uncontrollable drop in
  system voltage following a large disturbance
• Two basic ways to incite voltage collapse
• Sharp rise in system load
• Major outage

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Increase in Load
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Change in System
Pre-disturbance
Post-disturbance
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System Representation
Utility Service

• IEEE standard one-line diagram for a refinery
• Used PSSS\E and IPLAN to model load and impedance
  of the utility service
• Create nose curves

Generator 1
Generator 2
M
M
M
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Normal Operation
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Generator 1 Offline
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Generator 2 Offline
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Utility Service Only
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System Limitations

• Design system for worst case scenario
• The further away from the nose point the less
  likely voltage collapse is to occur

Generator 1 Generator 2 Nose Point Impedance
ON ON NONE
OFF ON 0.060j0.480
ON OFF 0.045j0.360
OFF OFF 0.0057j0.0456
Worst Case
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Validation

• Test the utility system impedance limitations
  using dynamic simulation
• This will allow for
• Variation of the loads
• Variation of the generator operations

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Application

• Problem areas can be identified using the design
  limitations
• The improvements of these areas will vary in
  effectiveness and cost
• The cost of improvements will need to optimized

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Cost Optimization

• A problem area is identified and a solution must
  be acquired in a 10 year budget
• The cost functions at 1000 per year are given
  as
• Tree Trim
• Protective Equipment
• Over a 10 year period the costs are
• Tree Trim 150,000
• Protective equipment 126,400

Best Option
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Future Design Possibilities

• Effects of multiple potential voltage collapse
  customers supplied by a single feeder

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References
1    H.O. Wang, E.H. Abed, R.A. Adomaitis,
A.M.A. Hamdan Control of Nonlinear Phenomena at
the Inception of Voltage Collapse Institute for
Systems Research, University of Maryland, March
1993.   2    T.V. Cutsem, C. Vournas, Voltage
Stability of Electric Power Systems, Kluwer
Academic Publishers, Boston, 1998.   3    Y.
Mansour, Voltage Stability of Power Systems
Concepts, Analytical Tools, and Industry
Experience, IEEE Press, New York, 1990.   4   
H.G. Kwatny, A.K. Parrija, L.Y. Bahar Static
Bifurcation in Electrical Power Networks Loss of
Steady-State Stability and Voltage Collapse IEEE
Trans., Circuits Systems, 1986.   5    B.D.
Hasssard, N.D. Kazarinoff, Y.H. Wan Theory and
Applications of Hopf Bifurcation Cambridge
University Press, Cambridge, 1981.   6    A
Seidman, H.W. Beaty., H. Mahrous, Handbook of
Electric Power Calculations,






McGraw Hill , New York ,1997.   7    R.C.
Dungan, M.F. McGranaghan, H.W. Beaty, Electric
Power System Quality, McGraw Hill, New York,
1996.   8    J.D. Glover, M. Sarma, Power
System Analysis and Design, PWS Publishing Co.,
Boston1994.   9    C.L. DeMarco, A.R. Bergen,
A security Measure for Random Load Disturbances
in Nonlinear Power System Modals, IEEE
Transactions on Circuits and Systems, vol.
CAS-34, no. 12, December 1987.   10 T.V.
Cutsem, C.D. Vournas Voltage Stability Analysis
in Transient and Mid-term Time Scale, IEEE
Transactions on Circuits and Systems, vol. 11,
no. 1, February 1996.   11 H.D. Chang, Chaos
in Simple Power System IEEE Transactions on
Circuits and Systems, vol. 8, no. 4, November
1993.   12 D.J. Hil, Nonlinear Dynamic Load
Models with Recovery for Voltage Stability
Studies, IEEE Transactions on Power Systems,
vol. 8, no. 1, February 1993.