Even with 300,000 miles of HV utility transmission lines spanning the US, there are few power firms not struggling with “gridlock,” Smart Wires Director of Product Management Frank Kreikebaum told us recently in an exclusive interview. In the last five years, his firm adopted and commercialized a power-flow-control technology that can help, Kreikebaum said.

Overcapacity on their networks has to be solved either by quickly diverting dangerously high loads to lines with available capacity or by building new infrastructure, he added. The Smart Wires product rapidly pushes power away from heavily loaded lines to those with available capacity.

In doing so, it prevents overloads and outages, cuts generation costs and eliminates the need for system upgrades, he added.

“The conventional approach is to spend more money building bigger systems. Ours is to use the current infrastructure more effectively,” Kreikebaum said.

Baltimore Gas & Electric (BGE) and the TVA use the Smart Wires hardware and software, he added. EirGrid, the state-owned power transmission operator in Ireland, is set to become the firm’s first European customer, with installation pending.

Georgia Institute of Technology Professor Deepak Divan developed the idea for the technology about eight years ago – when Kreikebaum was working as Divan’s research assistant. The National Electric Energy Testing Research & Applications Center (NEETRAC), a self-supporting, membership-based center within the School of Electrical & Computer Engineering at Georgia Tech, then chose Divan’s concept for further development and Kreikebaum went along to serve as project manager at NEETRAC.

NEETRAC in 2009 formed the Smart Wire Focused Initiative (SWFI) to advance Divan’s vision. SWFI had a core group of utilities, including BGE, the National Rural Electric Cooperative, Southern Co and the TVA.

The objective of the consortium, Kreikebaum said, “was to devote both cash and sweat equity to an effort that would define the requirements for products that would, first, increase impedance on an overhead high-voltage utility line and, secondly, redistribute power over other lines.”

How could the impedance be created? “We push back on the power using distributed series reactors (DSRs), which don’t physically close the wire. That could be done using breakers. Instead, the DSRs either restrict flow on the wire or slightly increase flow on the wire by adding inductance or capacitance into the line,” he added.

Theoretically, the idea looked like a winner.

QUOTABLE: Classically, before the existence of power-flow controllers, the power would flow along the line of least impedance. Now, we were looking at changing the impedance of each path to incent power to flow where it could be most easily and safely accommodated. – Smart Wires Director of Product Management Frank Kreikebaum in an exclusive interview

Out of that initiative, Smart Wires formed as a private firm in 2010, offering three products made in its new plant in Wilmington, NC:

  • Powerline Guardian uses distributed series reactors installed along the transmission line and attached directly to the conductor to increase impendence on overloaded wires;
  • Router, which redirects the power flow to less-loaded parallel wires, and
  • Powerline Commander, a proprietary monitoring, control and data aggregation software that offers bi-directional communications – most often using a wireless radio-based protocol – with the back-office operations control room, so utility personnel can monitor the system continually and reroute power within moments, if needed.

Extensive testing done

Smart Wires used a $4 million award from DOE’s ARPA-E to evaluate its wares in a two-year, real-world utility pilot. “If successful,” ARPA-E said in its mission statement, these “power flow control devices could increase overall grid transmission utilization by more than 30% and result in cost savings of over 50% when compared with simply upgrading transmission lines themselves.”

The TVA tested the Smart Wires technology on a 7.5-mile segment of the 21-mile TVA Knox-Douglas 161-KV transmission line near Knoxville, Tenn. The federally owned utility deployed 99 DSR units, which DOE monitored for a year.

The TVA in August reported its field installation had continuously run for 21 months and was available 100% of the time to provide power flow control and sensing to support TVA system reliability. The pilot system showed the ability to cut power flow by over 2.5%.

Southern Co installed 33 Powerline Guardian units on two 115-KW transmission lines managed by the Georgia Power Co and ran the network of devices continuously for 16 months. The devices were used to inject about 75% (on average) of the total possible impedance that could be achieved using the system, and 31 of the 33 units installed in March 2013 were still online at the end of 2014, Smart Wires said in January.

Southern Co expands trial

Southern Co decided to expand the system, doubling the number of installed DSRs and working toward integration of the Powerline Commander software with the utility’s existing energy management system (EMS).

Smart Wires now sees its technology not only addressing reliability concerns but also “providing additional values to the utilities,” Kreikebaum said. “For example, a utility would be able to plan for Smart Wires just a year ahead of time, compared to the 5-10 years of planning that the power company would need to do to bring a new plant online.

“When you are thinking about new infrastructure, you end up constraining capital and making choices based on that decision. With Smart Wires, you can wait to make those choices. The utility is able to deploy on a project that has value to it and its customers, rather than in anticipation of a potential need.”

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