Utility Design to Eliminate Voltage Collapse

1. Utility Design to Eliminate Voltage Collapse Presented by Jason Taylor

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

3. Motivation • Interest in utility system design • Potential “Hot Spot” of activity

4. 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

5. Increase in Load

6. Change in System Pre-disturbance Post-disturbance

7. 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

8. Normal Operation

9. Generator 1 Offline

10. Generator 2 Offline

11. Utility Service Only

12. System Limitations • Design system for worst case scenario • The further away from the nose point the less likely voltage collapse is to occur Worst Case

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

14. 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

15. 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

16. Future Design Possibilities • Effects of multiple potential voltage collapse customers supplied by a single feeder

17. 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.