Increase electric power flow in existing transmission lines,

instead of building new linesKalyan Sen, Ph.D., P.E.

senkk@ieee.org

16 June, 2009 Washington, DCIEEE Energy Fly-In

OverviewElectric power from the generation in one location to the loads in other locations flows through the path of least resistivity, just as water flows in a river.“Free flow” makes some transmission lines overloaded and others underloaded.

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PowerSource

Load

Load

Overview (cont’d)Energy needs to be transported from the generating point to the end-user along the most desirable path, just as we use lock and dam in a river.

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Controlled Path

PowerSource

Load

Load

PowerFlow

Controller

Overview (cont’d)

You know what would be great?  It would be really great if someone could increase the electric power flow through an existing transmission line in a cost-effective way. Then, we would not have to build new, expensive transmission lines for many years to come, saving on both the cost of the new lines and the environment.

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Problem StatementNew transmission lines are needed due to– Increased demand of electricity– Integration of renewable energy sources like

wind and solar power with the electrical grid.

Public is not in favor of building new transmission lines as it impacts them.An average line is used less than 50% of its capacity.The transmission line carries useful real power (beer in a glass) and useless reactive power (foam on top of the beer).

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Problem Statement (cont’d)Present power flow control methods increase both real (beer) and reactive (foam) power flow simultaneously.The line’s usage is maximized when it carries real power with minimal reactive power (beer with minimum foam).Electric power from the generation in one location to the load in another location often travels through unwanted paths, causing extra power losses in the lines, thus less efficiency.

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What is needed?

Demonstrate with a power flow controller in an existing transmission line that the real power flow can be increased significantly without increase in the reactive power flow.Reduction in reactive power flow leads to– freed up capacity of the line– increased flow of real power– less demand of reactive power from generator– Increase of efficiencies of the generators and step-

up transformers.

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What is needed? (cont’d)

Demonstrate that the existing grid can– Integrate renewable supplies– Accommodate Plug-in electric/hybrid vehicles– Reduce energy infrastructure requirements– Lessen dependence on foreign oil.

Get the public re-excited about “better” electric transmission lines.Create viable American jobs and export products of global significance.

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Intended Paradigm Change

Raise the public’s expectation that existing transmission lines can efficiently deliver more reliable power from both conventional and growing renewable sources to customers across the nation without building new lines for years to come, thus less impact on the environment and the public.

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Expected Radical Breakthrough

To avoid building new, expensive, high-voltage electric transmission lines.To relieve overloaded lines by redirecting power to the underloaded lines, thus avoiding blackouts.To transmit power through the shortest transmission path, reducing line losses, thus increasing efficiency.

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Benefits of the Radical Breakthrough

Curtail the most polluting fossil power plants in the world– Phase-out the most polluting fossil power

plants in the U.S.– Reduce construction of new fossil power

plants in developing nations

Integrate renewable sourcesAvoid building new, expensive, high-voltage electric transmission lines.

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Summary

Demonstrate a novel, low-cost power flow controller to increase the real power flow in an existing transmission line without increase in the reactive power flow.The power flow controller must have– Better than 99% efficiency– Low-cost approach with small installation

footprint– High reliability via low component count.

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Further Reading

K. K. Sen and M. L. Sen, Introduction to FACTS Controller: Theory, Modeling, and Applications. New York: IEEE Press and John Wiley & Sons, Inc. 2009.

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