ABB Inc. has received UL1741 certification for the power conditioning system it has developed for fuel cell power generation. ABB initially applied for the certification in late 2004, and has received it in 2005 by meeting the requirements.
The UL1741 standard, titled “Inverters, Converters, Controllers and Interconnection System Equipment for Use with Distributed Energy Resources,” is an Underwriters Laboratory (UL) standard essential to the distributed generation market. While UL1741 is only a few years old, the market has adopted it as a requirement for anyone building products and systems for distributed generation applications.
UL1741 addresses “unintentional islanding.” Islanding is the action of separating a power source from the electrical grid. Unintentional islanding happens when a utility grid is down, usually for maintenance, and the distributed generation source continues to feed the grid.
Unintentional islanding could cause the power lines to still be energized without the knowledge of the utility, consequently placing workers on that line in danger. Also, major equipment can be damaged and system reliability could be compromised, reducing overall power quality. UL1741 requires a feature called “anti-islanding” that automatically shuts down the distributed generation site in such a condition.
