Press releases

Voltwerk inverters meet requirements of low voltage directive

Voltwerk VS range supports improved national grid integration

(Hamburg) Since January 2012, all Voltwerk VS range inverters have fulfilled the requirements of the VDE-AR-N-4105 code of practice. This includes a specification that systems with an output of 3.68 kVA or more must provide reactive power. Voltwerk VS range inverters facilitate in systems with an output of 3.68 to 13.8 kVA the specified cos (φ) of 0.95 and in larger systems the specified cos (φ) of 0.9. The reactive power gets regulated based on a characteristic curve. This thus alleviates what is perhaps the greatest problem of decentralised current feed-in, i.e. increased voltage. Fed-in reactive power enables a lowering of the voltage, meaning that a larger number of solar panel systems can be installed.

The VDE code of practice came into force back on 1st August 2011. However, installers were still permitted to fit inverters that complied with the previous shut-off parameters up until the end of the year. Since January 1st, the only systems that are now permitted to be connected to the grid are those that comply with the new regulation.

Directive also solves the 50.2 Hz problem
Another element included in code of practice VDE-AR-N-4105, ‘Power Generation Systems Connected to the Low-voltage Grid’, is a solution to the so-called ‘50.2 Hz problem’. Until now the rule was that all regenerative power generation systems had to instantly disconnect from the grid even if they only temporarily exceeded the upper frequency limit of 50.2 hertz. That presented the risk of losing a great deal of power output, which would have exceeded the reserves of the German electricity grid. This would have resulted in a wide-scale power cut. As the majority of solar panel systems installed in Germany feed into the low-voltage grid, revised regulation of the shut-off procedure was urgently required.

“The amendment of the low-voltage directive takes account of the steadily increasing proportion of solar energy in the German electricity mix. Along with other manufacturers, we were involved early on in the drafting of these specifications. Therefore we are able to offer our customers in good time products that are compliant with the guidelines,” explained Steffen Elster, Head of Product Management at Voltwerk. “All string inverters leaving our warehouse have conformed to the low-voltage directive,” added Elster. Voltwerk has for several months already been selling appliances compliant with the transitional rule. For inverters made before this time an update is available for free download from www.voltwerk.com, which can be installed using the Voltwerk InverterSetup tool.
 

Press contact at Voltwerk

Christoph Lapczyna 
voltwerk electronics GmbH 
Anckelmannsplatz 1 
20537 Hamburg 
fon: +49 40 27142 1640 
fax: +49 40 27142 1855 
mail: c.lapczyna@voltwerk.com