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The Institute has replaced the 2011 UL 1699B standard with the new IEC 63027 for inverters incorporating arc flash detectors to improve safety and efficiency in inverter technology.
The Fraunhofer Institute for Solar Energy Systems ISE has announced the publication of a new international test standard for inverters incorporating arc flash detection devices: the new IEC 63027 standard will replace the UL 1699B standard issued by the certification body based in Illinois Underwriters Laboratories (UL) in 2011, when arc fault detectors became mandatory in the United States.
Series arcs in PV systems occur as a result of contact problems, for example due to poor solder joints on the module or in the inverters DC wiring. In an emergency, high temperatures at faulty contact points can cause the system to burn.
“The new IEC standard removes some of the weaknesses of the old US standard, which did not sufficiently simulate actual operation,” the institute says. "As a result, many arcs were not detected, because they did not reach the alarm threshold values ??or because false alarms were triggered."
Fraunhofer ISE has also developed a modular test bench that it defines as unique for testing photovoltaic inverters with integrated arc detectors. These warning systems, integrated into the inverter, increase the safety of solar installations because they automatically disconnect power in the event of an electric arc. The institute claims that the new test bench is currently deployed at its TestLab Power Electronics, where devices for DC voltages up to 1,500 V are already tested.
According to the Fraunhofer ISE, undetected arcs and arcs in solar inverters can only be avoided with a realistic test setup that uses a DC electronic source as a PV simulator, instead of actual PV modules. Current flows from the PV simulator to the inverter via a precisely separable contact point. The contact point is formed by two ball-shaped tungsten electrodes, which move apart at a defined speed. Thus, a characteristic arc is ignited. Fixed test parameters (gap and speed) can be stored and selected for the test sequence. To ensure that the measurement result is not influenced by the PV simulator, a filter network is connected between the inverter and the simulated PV system.
“We are expanding the range of services offered by our TestLab Power Electronics, where we carry out accredited tests according to grid codes, efficiency measurements and inverter impedance spectroscopy investigations,” said Steffen Eyhorn, head of TestLab Power Electronics. |
