String Inverters Single-Phase Solutions for the North American Market (2011): Page 4 of 10
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Fronius. A privately held firm, Fronius was founded by Gu¨nter Fronius in Pettenbach, Austria, in 1945. The company’s initial products included battery chargers and welding transformers. Today, these fields make up two of the three Fronius business divisions. Its third and most recent business division is solar electronics. In 1995, Fronius entered the solar market with the Sunrise grid-direct inverter. According to a 2011 report published by GTM Research, Fronius is currently the fourth-largest global supplier of inverters. Since the company added light commercial central inverters to its product mix only recently, this substantial market share is built primarily on its offering of string inverters. The company currently employs approximately 3,000 people. It has sales representatives in more than 60 countries and 17 foreign subsidiaries. While solar inverter production had been centralized at the company’s Sattledt location in Austria, which opened in 2007, Fronius recently opened a Canadian subsidiary with an initial annual production capacity of 250 MW.
The Fronius IG-series of inverters was first launched in Europe in 2001. Two years later, the company released the Fronius IG 40 and IG 60, its first multiple power stage inverters. By using intelligent control of multiple power stages, Fronius is able to divide, balance and otherwise optimize the operation of individual inverter power stages. The company refers to this as its MIX concept. In addition to the obvious manufacturing efficiencies of having a standard power stage, Fronius touts improved operational efficiency across all power ranges and increased component lifespan as benefits of a multiple power stage inverter design. MIX technology is now ubiquitous across all Fronius product lines, including its light commercial CL inverters.
The first UL-listed multistage Fronius IG string inverters were released to the North American market in 2004. Four years later, the company released updated IG Plus inverters to the US and Canada. This product line currently includes seven single-phase string inverter models, ranging in capacity from 3 kW to 11.4 kW, capable of interconnecting to the grid at 208, 240 or 277 Vac. The UL-listed IG Plus product line also features a pair of 3-phase inverters, rated at 11.4 kW ( for 208 or 240 delta services only) and 12 kW ( for 277 wye service only). IG Plus inverters are housed in NEMA 3R enclosures and actively cooled using variable-speed fans. Source-circuit fuseholders are provided for the ungrounded dc input conductors, as is an inverter-integrated dc disconnect. Fronius uses a highfrequency, transformer-based inverter topology, which means that its products are not as heavy as comparably sized 60 Hz transformer-based inverters.
In reference to increasing the company’s North American market share, Gord Petroski from Fronius USA, reports: “We are proactive with our efforts in the US market, with very aggressive pricing and products in stock and ready for immediate shipping.” He also points out that the company’s product line is both proven and well suited to the market. “Our IG Plus series has a consistently wide MPPT voltage window for maximum energy harvest in diverse weather conditions,” he explains. “This feature is needed in a market that is as varied as the US and Canada.”
Ingeteam. Headquartered in Zamudio, Spain, Ingeteam brings more than 30 years of experience in the power electronics design and manufacturing sector. It began developing products for the renewable energy industry in the 1990s. The company is privately held, with a network of sales offices that includes locations in Brazil, China, the Czech Republic, France, Germany, Italy, Mexico, Spain, and the US. Ingeteam’s global business structure includes six primary units: energy, industry, shipbuilding, railway traction, basic technologies and services. In 1990, Ingeteam Energy, S.A. was founded to develop electrical and control systems for industrial-scale wind power and PV technologies. The 1990s also marked the beginning of the Spanish company’s international expansion. Today, Ingeteam has more than 3,500 employees worldwide and offers a wide range of grid-connected and stand-alone PV inverters, marketed under the Ingecon Sun brand, with rated capacities from 2.5 kW to 625 kW. Manufacturing facilities are located in Spain and the US. String inverters represent approximately 15% of the company’s overall revenue from inverter sales.
Ingeteam first introduced a 2.5 kW transformer-based, single-phase string inverter model for the European market in 2000. A 6 kW transformerless string inverter, also destined for the European market, was released in 2005. More recently, Ingeteam developed a new family of 3-phase transformerless string inverters with power outputs from 10 kW to 18 kW, again for the European market. The company’s first string inverter models developed for the US, the transformer-based Ingecon Sun Lite 5 U and transformerless Ingecon Sun Lite 5 TL U, have been listed to UL 1741. CEC eligibility is pending. The two Ingecon Sun Lite inverter models became available to North American customers in July of this year.