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n Brazil, the challenge for the electric power company is to insure stable transmission of

power over high-voltage lines span-ning far-flung geographical extremes. In environmentally attuned Denmark, it’s to integrate the irregular pulse of offshore wind energy seamlessly with the central grid. Halfway around the world in Australia, the task is simply to ensure system stability by compen-sating voltage drops.As never before, electric power com-panies worldwide are straining to meet several imperatives: satisfy growing energy demand, deliver remote sourc-es of alternative power to sustainabil-ity-minded consumers, and – in an age of public concern over carbon foot-prints and greenhouse gases – waste as little electric energy as possible in its transmission. These market and policy goals often lead power companies around the world to the same solution: Flexible AC Transmission Systems – or FACTS – to assure grid stability and consis-tency. The Siemens product portfolio includes parallel compensation sys-tems, such as SVC and SVC PLUS, which

regulate voltages in networks with extreme use fluctuations, and series compensation systems, which increase the transmission capability of long-distance power lines. Although the basic concepts of FACTS are decades old, Siemens’ advances in system software and technical hardware have made them essential tools for power utilities striving for maximum grid performance. Parallel compensation FACTS aim at regulating voltage at times of extreme fluctuations in demand, as in indus-trial zones in Brazil or during the sum-mer months in Saudi Arabia, when a near-universal need for air-condition-ing stresses the grid and causes the network voltage to dip. With cutting-edge thyristor-based technology in-stalled at load centers or substations, the systems’ capacitor cans and reac-tor coils provide or take out reactive power, reducing the risk of system failure.Series compensation FACTS help power companies increase power transfer capability in overhead lines by electri-cally shortening their length, thereby reducing the resistance and thus the

power losses, an operational dilemma in any power transmission network. Increasingly, power companies turn to series compensation FACTS as an eco-nomic alternative to putting up new lines or substations.The systems accomplish improved power transfer with capacitor banks that are protected by metal oxide varis-tors (MOVs) to guard against light-ning or surges that might otherwise cause them to fail.A distinct advantage of FACTS is the flexibility of application – as confirmed by the responses of executives from eight electric power companies around the world, all Siemens customers, but each with a different set of operating challenges and goals. In the following article, all eight graciously answer the same three questions: Why they needed the FACTS solution, the posi-tive results they have experienced since installation of the system, and why they chose the Siemens product over other options. Here is what they told us.

Flexible AC Transmission Systems (FACTS) help to regulate voltage and reduce transmission losses. Based on transcripts of phone calls to eight utilities around the world, our author reports on how FACTS meet their local and systemic requirements.

Text: Chris Kraul Illustration: Lizzie Roberts

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Energy Challenges Worldwide

Just the FACTS

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As in many emerging countries, power supply problems faced by Paraguay’s main electric utility, Administración Nacional de Electricidad, or ANDE, flow directly from rapidly rising demand. In Para-guay’s case, load has grown at a staggering 9 per-cent annual rate in recent years, according to the utility’s Technical Manager Roberto Farina. Driving the demand growth is industrial expansion, but also increases in Paraguayans’ per capita income and consumption as a result of the global commod-ities boom. Much of ANDE’s demand growth is occurring in and around Pedro Juan Caballero, a northern city on the Brazilian border that has seen a great increase in industrial and commercial activity. Rising peaks in power consumption, particularly during the work week, have created voltage level problems for the entire grid.Although 99 percent of Paraguay’s electricity is hydro, ANDE was facing the necessity of building a fossil-fuel-powered generation plant to balance the wild swings in voltage levels in the north. That is, until Farina and his technical staff did a cost-benefit analysis of a FACTS alternative. Hands down, the option of a Siemens SVC system at the Horqueta transformer station proved a more economic alternative. As a bonus to the balancing by the SVC, Farina figures an active power of 40 megawatts could additional-ly be transmitted to the northern grid once fully installed this August. “In a technical and an economic aspect, Siemens met the criteria and made the lowest bid,” Farina says. “We have great hopes that the FACTS will solve our voltage issues – and help us keep up with demand.”

For Hydro One, an electric power transmission company based in Toronto, the chal-lenge was clear: How to insure voltage support during the decommissioning of one of the region’s largest generation stations, the highly pollutive 2,000-megawatt coal-burning power plant in Nanticoke in southwestern Ontario. To reduce its car-bon footprint, power generator Ontario Power Authority will replace it by 2014 with wind, added nuclear and natural-gas-fueled generation. Assuming load remains the same, the loss of that much capacity posed a high risk of serious voltage loss and possible system failure and blackout, says Hydro One’s Major Projects Manager Lake Singh. The “on-and-off” nature of wind generation that is coming online to replace it also will cause voltage to fluctuate. Moreover, the power that will replace Nanticoke will come from as far as 200 miles away, pre-senting further risks of higher resistance and lessened transmission capacity. The solution Hydro One chose was to install a Siemens SVC right on the Nanticoke power plant site to provide voltage support during “contingency conditions” as the big generation station was phased out. Why Siemens? Economics were decisive, but even more so were studies that Singh’s team carried out that showed the com-pany’s SVC technology generated no “harmonics,” or distorted sine waves inside the voltage that can cause power loss and damage to equipment. “This is the backbone of our transmission grid, and as a transmitter we have to keep it as clean as electrically possible,” says Singh. “Siemens technology offered us the cleanest technical solution.”

Insuring grid stability and voltage support are routine tasks for man-agers of most power companies around the world. For Saudi Electric Company (SEC), which faces mind-boggling extremes in climate, geog-raphy and load fluctuations, they can be Herculean challenges. Saudi Arabia’s principal power company must transmit electricity over immense distances that separate cities and oil installations, and that requires long transmission lines. Rising oil prices have generated in-creased industrial activity, particularly in energy-intensive petrochem-icals. But it is the explosion of residential and commercial air-condi-tioning use that has caused perhaps the biggest threat of voltage collapse and blackouts.According to Ahmed Al-Mubarak, Manager of SEC’s strategic planning department, system-wide load during scorching summer months goes as high as 50,000 megawatts, or two-thirds more than the 30,000-megawatt load during winter, when AC is not necessary. More than 80 percent of summer demand is to power air-conditioning units. Somehow, the company must balance out the system, during those extreme load swings. To accomplish that, Saudi Electric is in the process of installing its fourth Siemens FACTS in the country’s central region. The most visible evidence of beneficial effects is in the city of Jeddah on the Red Sea where, prior to the installation of the first SVC system in 2006, the city was regularly victimized by blackouts. Now, system failures simply “don’t happen,” says Al-Mubarak.

Denmark has set a national goal of eliminating all fossil-fuel-burning electric power plants by 2050. That ambitious target has presented power company SEAS-NVE, the country’s largest consumer-owned utility, with an enormous challenge, namely how to integrate innovative sources of renewable energy into the region’s power capacity, while assuring customers of sta-ble and reliable electric power.To meet the first part of the chal-lenge, SEAS-NVE is shifting to an increasing reliance on wind power generated in the Baltic Sea, including the 160-megawatt Nysted and Rodsand wind farms located offshore near the island of Lolland. The 162 wind tur-bines there generate enough power at peak performance to light 300,000 households. The second part of the challenge – keeping the grid stable as more wind power is brought online – was more complicated, the utili-ty’s Managing Director Jesper Hjulmand explains. The tradi-tional solution would have been to build a power plant in the southern area of coverage to balance reactive power when the wind turbines are still. But working with Siemens engi-neers, the utility settled on a much more cost-effective FACTS solution: a SVC parallel compen-sation system to provide reac-tive power and voltage stability. The system also successfully met a third challenge: It was built indoors in a village with strict noise restrictions. “In terms of technology and price, it was the best solution,” says Hjulmand. And as for stabilizing the always fluctuating supply of wind power? “Several times, the SVC has helped us avoid blackouts from big leaps in voltage.”

Jesper Hjulmand, Managing Director, SEAS-NVE, Denmark

Lake Singh, Major Projects Manager, Hydro One, Canada

Roberto Farina, Technical Manager, Administración Nacional de Electricidad, Paraguay

Ahmed Al-Mubarak, Manager of Strategic Planning, Saudi Electric Company, Saudi Arabia

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The decade-long global boom in coal, a commodity that is mined right in its own backyard in the mineral-rich Bowen Basin, has been a huge business stimulus for Powerlink Queensland, an electric transmission utility in eastern Australia. Electricity is needed not only to extract the coal, but also to transport it to east-ern ports via electric-powered trains of the QR National Railroad.But the 10 percent annual increases in coal exports of late have also presented the transmission company with an unprecedented system stability challenge. Simon Bartlett, Powerlink’s Chief Operating Officer, likens the loss of voltage in the transmission system during heavy electric train traffic to the loss of water pres-sure when everyone is out watering their yards. “It’s even more complicated with energy. If you don’t do something to compensate for the drop in voltage, you risk system failure and blackouts,” Bartlett says. To deal with added strain, Powerlink considered extending its high-capacity grid all the way out to mining areas located some 250 kilometers inland from Brisbane, the provincial capital and population center. Instead, after a competitive tender, the company

is installing nine Siemens SVC parallel compensation devices at strategic locations on the grid. The upshot for the railroad is that it can mothball some diesel-power locomotives it has been using provisionally and complete its conversion to “green” all-electric rail transport. For Powerlink, the SVCs mean more reliable service. “They enable us to manage phase balancing in a more cost-effective way,” Bartlett says.

Long Island Power Authority (LIPA), the municipal utility that serves New York’s Long Island and part of Queens, is in the enviable position of owning transmission infrastructure so efficient that it’s more economic to import the bulk of its power than to generate elec-tricity itself. Still, the eastern half of the 120-miles- long island is vulnerable to voltage faults, mainly because transmission interties are all situated from the mid-dle to the west end of the island. That means the utility must maintain, on a contingency basis, several inefficient and highly polluting oil-burning power plants on the eastern half as reactive sources to keep voltage balanced, par-ticularly during warm-weather air-con-ditioning season. “As you get closer to the east end of the island, you don’t have [power source] redundancies, so any fault causes a pretty considerable voltage dip – and that can get you to voltage collapse if you don’t have the devices out there to absorb the impact of the fault,” says Nicholas Lizanich, Senior Vice Presi-dent for Operations. Recently, LIPA bought two new Siemens SVC PLUS systems that Lizanich hopes will mean the utility will never again have to use the inefficient generators. The units also include high-speed, thy-ristor-switched capacitors that allow rapid turning on and off of reactive VARs, a component that helps bring addition-al strength to the grid. “We evaluated Siemens on cost and tech-nology solution, and it filled the need. I also liked the idea that the system was relatively small,” Lizanich says. “I could fit it on the real estate we had.”

Manaus and Macapá are two fast-growing Brazilian cities situated on the Amazon River that on a map may look isolated. But both, especially Manaus, are up-and-coming industrial and agribusiness centers with expanding populations and thus increased demand for electric power. Each is highly dependent on a 1980s-era hydropower project – the mas-sive 8,370-megawatt Tucurui complex in Para state that is connected to both cities by transmission lines operated by Isolux Corsan. The operational challenge lies in the 800 miles of distance that sepa-rate Tucurui from Manaus, the 500 miles from the dam to Macapá, and the increased transmission line resistance over such long cables that, unless compensated for, causes power loss. In a new initiative to insure system stability, Isolux Corsan has bought several Siemens series compensations systems: 3 SVC units and 10 FSC systems to be installed by year-end at various substations along the grid. Isolux Project Manager Christian Mendes describes the Siemens FACTS as “essential in increasing power sys-tem stability and transmission ca-pacity – most likely, these lines would not be feasible without FACTS devices.”Asked to explain why Isolux chose Siemens products over the competi-tion, Mendes says Siemens submit-ted the lowest bid, possibly because it produces the capacitor units at a factory near São Paulo. The compa-ny’s strong local service staff, as well as its technology center located in Brazil, made Isolux confident that Siemens would provide a good after-sales response, reports Mendes.

Simon Bartlett, Chief Operating Officer, Powerlink Queensland, Australia

Nicholas Lizanich, Senior Vice President for Operations, Long Island Power Authority, USA

Christian Mendes, Project Manager, Isolux Corsan, Brazil

Transpower, operator of New Zealand’s long and slender electric trans-mission network, delivers power to a highly dispersed population spread out across 1,000 miles of natural obstacles including mountains, forests, steep valleys and the Cook Strait, which separates the country’s two principal islands. Added to the geographical realities is seismic activity, which most recently made headlines when the December 2010 earthquake devastated Christchurch, the country’s second-largest city. A few years ago, when Transpower’s relatively long transmission lines, which connect major loads to generation centers, began to reach their thermal limits, the company began looking for ways of maximizing its existing assets – reliably increasing power transfer without having to invest in new transmission lines.The company ultimately decided to buy a STATCOM, or package of dynamic reactive devices, that included two Siemens SVC PLUS units for the Kikiwa station at northern South Island. Transpower’s Stuart MacDonald says the units have improved the security of service, espe-cially to remoter parts of the island that in the past were prone to dete-riorating voltage quality. The SVCs have also enabled the transmission company to defer building new transmission circuits, saving customers money and avoiding damage to the environment.Low cost and confidence in the Siemens brand were decisive factors in Transpower’s bid award. “It is a large engineering company with deep technical resources and capabilities, and long project delivery experience, which gave us confidence under a tight schedule,” says MacDonald.

Stuart MacDonald,

Power System Analysis Manager, Transpower, New Zealand

A former foreign correspondent for the Los Angeles Times, Chris Kraul is a freelance science, technology and business writer based in Bogotá, Colombia.

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