Posted November 13th, 2009
President Obama said late last month that the time is now “to build a clean energy superhighway that can take the renewable power generated…and deliver it directly to the American people in the most affordable and efficient way possible.” In effect, creating what has become known as the “smart grid.”
Polytechnic Institute of NYU’s Francisco de León, professor of electrical and computer engineering, is one of the researchers whose decades-long work to improve the efficiency of electricity delivery will contribute to the massive upgrade the President is urging for.
One of his more recent discoveries, which he’ll present at the Advanced Energy Research conference on November 18 - 19 in New York City, improves the way renewable energy is sent to existing electrical grids.
Most renewable energy travels into the grid through what are called “power electronics controllers.” Professor de Leon has discovered a way to control them to dampen a characteristic that affects all power systems: oscillation, the fluctuation of electric power.
When you turn a light on and off you create an infinitesimal change in the amount of electrical power demand in the grid. But think about what happens when a TriBeCa printing house turns on all of its presses at once, or if all of the Garment District’s workshops shut down their industrial sewing and pressing machines at the same time. Such large-scale, abrupt shifts in demand could cause increasing oscillations of power— think blackouts and outages — if technology wasn’t in place to dampen them.
“All systems have oscillations and all systems need a way to dampen them,” explains Professor de León. “What I’ve found is a way to dampen oscillations in the system using the already present power electronics controllers that are needed to connect renewable energy sources to the grid. Without the control strategy, the energy would be able to go through, what the new control strategy does is to enhance the way green energy can be used to dampen oscillations.”
An abstract of Professor de León’s presentation can be found below.
Polytechnic Institute of NYU is a sponsor of the 2009 Advanced Energy Research conference. Learn more about the conference at aertc.org.
In this presentation it is shown the potential that alternative power generation plants (mostly DGs) have to damp oscillations in large electrical power systems. Electrochemical fuel cell, gas turbine, wind turbine, solar, photovoltaic, etc. plants can provide local damping when they inject power in proportion to the frequency deviation from the standard reference. The damping is introduced through the power electronic converters that most DGs use to interface with the power system. Another important contribution presented is the use of a unidirectional damping strategy with only absorption (or only injection) of power. As a feasibility study, the goal of this research work was to evaluate the necessary size (as a fraction of the overall power) that the DGs must have to damp out system oscillations in a few seconds. Examples on power systems of two, six and thirty-nine nodes are presented for illustration.