Avoiding voltage collapse on transmission and distribution lines

smartelectricnews.com Special : Interview with Jack McCall, Director Business Development - HTS T&D Systems, AMSC Power Systems

American Superconductor Corporation (AMSC) identifies the U.S. power grid market as one of its core growth drivers.

Recently, in its third quarter (ended December 31, 2008) results, AMSC shared that more than $27 million of its $46 million in third-quarter bookings were for its D-VAR Smart Grid solutions. With these new orders, the company now has more than $175 million out of the total of $602 million in backlog that it expects to recognise as revenue in fiscal 2009.

Commenting on plans for this year, Jack McCall, Director Business Development HTS T&D Systems, AMSC Power Systems told smartelectricnews.com: “We are focused on increasing global sales volumes for our D-VAR and SVC reactive compensation solutions. We also will be completing our prototype Secure Super Grids system for Consolidated Edison in 2009.”

McCall spoke in detail about preventing blackouts, AMSC’s Smart Grid D-VAR and Static VAR Compensator (SVC) solutions, and much more. Excerpts:

smartelectricnews.com: With reference to your company's technologies, can you provide an insight into what sort of progress has been made when it comes to preventing blackouts and relieving congestion on existing transmission lines?

Jack McCall: Superconductor power cables offer tremendous power handling capacity combined with very low impedance, making them an ideal solution to addressing grid congestion, particularly in urban areas or where right-of-way is limited. Superconductor cables are also being deployed in NYC in a configuration called Secure Super Grids that allows for a unique method to interconnect substations as a means of increasing grid reliability and preventing blackouts.

On overhead transmission lines, utilities are increasingly looking to install real-time monitoring systems, reconductoring and using other methods of increasing line thermal limits. Often, they find that this is only increasing amperage ratings and any increased power transfer may be limited by overriding voltage stability concerns. AMSC D-VAR and SVC systems provide real-time voltage stability and VAR support necessary to assure that this increased ampacity translates into more power transferred.

smartelectricnews.com: How efficiently are voltage problems being sorted out today?

Jack McCall: Reactive power compensation is necessary to stabilise voltage, relieve power grid congestion, improve electrical efficiency, and prevent blackouts in power grids. AMSC’s Smart Grid D-VAR solutions detect and instantaneously compensate for voltage disturbances by dynamically injecting leading or lagging reactive power into the power grid.

D-VARs are being used in a wide range of applications, including voltage regulation and grid reliability, optimisation of power transfer capacity on stability-limited transmission networks, and reactive power support for wind farm grid interconnection. These solutions allow wind farm developers to meet the dynamic voltage requirements being adopted by countries around the world to protect the grid from the variable voltage levels stemming from wind farms.

AMSC recently announced that National Grid will deploy a large-scale, turnkey D-VAR solution to ensure reliability of the local power grid it manages under an agreement with Long Island Power Authority (LIPA). Including this latest deployment, AMSC has received orders for over 60 STATCOM or Static Compensators power grid solutions worldwide showing these solutions are now coming of age. In total, AMSC’s D-VAR customers include a total of more than 20 electric utilities and 40 wind farms worldwide.

smartelectricnews.com: How does AMSC's SVC provide many benefits at the transmission, distribution and even end-user level?

Jack McCall: AMSC's Static VAR Compensator (SVC) solutions eliminate voltage sags and flicker, giving electric utility companies and manufacturing operations a cost-effective way to safely connect large electrical loads to the local power grid. AMSC’s SVC systems are highly portable, modular and can be field-modified, thereby reducing the costs normally associated with upgrades. They routinely solve problems caused by starting large motors, metal shredders and crushers, sawmills, pump or pipeline stations, shipyards, coal mines, feed plants or kindred processes. These solutions also solve arc furnace flicker problems and are utilized to stabilize power transmission grids.

By using an SVC, electric utilities can eliminate voltage sags and flicker issues caused by such problematic electrical loads without making larger permanent or fixed investments in their power system. SVC solutions offer customer-side benefits as well by providing a more stable voltage supply and a higher power factor to the end user. In many cases, the availability of an SVC will permit an end customer to further expand their facility without impacting other customers located on the same circuit.

smartelectricnews.com: There are devices in the marketplace that can optimise new and existing transmission and distribution lines. What new trends have you witnessed in this arena from AMSC's perspective?

Jack McCall: Our D-VAR and SVC solutions help to optimise existing transmission and distribution assets. Because our solutions eliminate voltage instabilities, power grid operators can oftentimes increase power capacity of their existing T&D assets, providing a very rapid return on investment.

smartelectricnews.com: Can you describe the role of superconductor power cables and AMSC’s Secure Super Grids technology in a smart grid?

Jack McCall: Superconductor power cables and AMSC’s Secure Super Grids technology meet each of the following Smart Grid criteria detailed by the Department of Energy: 1) Accommodate all generation and storage options, 2) Provide power quality for the digital economy, 3) Optimise assets and operate efficiently, 4) Anticipate and respond to system disturbances self-heal, and 5) operate resiliently against attack and natural disasters to resist attack.

AMSC’s Secure Super Grid (SSG) technology is a “system-level” superconductor cable solution that fulfills these criteria, which are vital to enhancing over-taxed and aging power grids in the U.S. and around the world.

AMSC’s SSG technology increases both the capacity of T&D infrastructure and the fault current handling capability of dense urban circuits. This solution utilizes customised superconductor power cables and ancillary controls to deliver up to 10 times more power than conventional copper cables while at the same time suppressing power surges - or fault currents - that can result in critical outages including widespread blackouts. Superconductor cables create resilient, self healing power grids that can survive attacks and natural disasters. HTS cables can increase transmission efficiency and significantly enhance the flow of power under city streets to enable, for instance, widespread adoption of PHEVs. Uniquely, AMSC’s SSG technology also allows for the construction of multiple paths for electricity flow in metropolitan power grids to ensure system redundancy when individual circuits are disrupted due to severe weather, traffic accidents or willful destruction.

High-capacity, very low impedance superconductor power cables generate little to no magnetic field. The very high power capacity and small footprint of superconductor cables makes them much easier to site, particularly in dense, urban areas. As such, the compact size and low environmental impact of HTS cables offers new ways for grid planners and operators to upgrade and increase the capacity of electric distribution networks.

HTS cables have been well demonstrated at electric utilities and are now being deployed in the grid. Over the past two years, three of these cables have been energized in the United States. Stand-alone fault current limiters based on superconducting materials also offer a new vista in grid security and technical control of system operating parameters.

smartelectricnews.com: How can superconductor power cables be utilised to transport renewable energies from remote areas to highly populated urban areas where power is needed?

Jack McCall: We believe superconductor power cables will play a big role in the mission to efficiently transport renewable power to the load center. While much of the long-haul power transmission from large renewable generation sites over the next several years will be accomplished with overhead power lines, as that load approaches cities, it must be carried underground. Superconductor cable technology is able to carry this power more efficiently and in a much smaller space than conventional copper cables. We also believe that direct current (DC) superconductor power cables will eventually play a role in long-haul power transmission.