System Stability Regulation

According to Section 6 of the System Stability Regulation (SysStabV), transmission grid operators are obliged to provide the distribution grid operators connected in their grid area with the data required for retrofitting in accordance with Sections 4 and 5 SysStabV. This involves information on which inverted rectifier are to be retrofitted according to which solution variants from the SysStabV. This data is published by the transmission system operators (TSOs) in the form of an inverted rectifier list. The operators of distribution grids are in turn obliged to carry out the retrofitting.

Inverted Rectifier

An inverted rectifier is a type of power converter that can generate alternating voltage from direct voltage. If, for example, solar direct current from photovoltaic systems is to be fed into the public grid, it is first converted into alternating current with a frequency of 50 hertz with the help of an inverted rectifier.

The corresponding inverted rectifier list and the list for the external decoupling protection devices as well as the corresponding explanations are available for download. Please note that this data is intended exclusively for distribution system operators and not for other parties such as installers. Further information is available on the BDEW website.

With the publication of the list with the version date 21.01.2013, the inverted rectifier list is complete. No further inverted rectifier will be added from this date.

inverted rectifier that are not included in the list do not have to be retrofitted, but must be listed in the report to the transmission system operator (please select the solution variant "S1 Not retrofitted - inverted rectifier not in TSO list" for these inverted rectifier in the "inverted rectifier-related retrofit data" worksheet in the "Solution variant or not retrofitted because..." column).

Irrespective of this, the frequency values for the conversion of individual inverted rectifier may still change. In this case, however, you will be informed separately by your responsible transmission system operator when the list is updated.

The published inverted rectifier list dated 25.03.2013 contains a new table sheet which includes so-called channel designations from the manufacturers SMA and Schüco. The background to this is that in some cases the correct type designation is not shown on the display when the device information is read out, but the channel designation. As a result, there may be an increased number of reports of channel designations that are not included in the original WR list. Please compare the entries with the existing list of channel designations and, if they match, request the correct type designation, which can be found on the type plate and in the system documentation.

An explanation of the distinction between the inverted rectifier list and the TSO report, which the distribution system operators submit to the transmission system operators on a quarterly basis, is also available for download in the list of links below.

To date (as of September 30, 2013), 14,330 systems and 193,717 inverted rectifier have been converted according to the reports submitted by the distribution system operators to the transmission system operators. Cumulatively across all distribution grid operators, a total amount of € 6,349,046.83 has been reimbursed by the transmission grid operators to date (as of 31.10.2013) (this corresponds to 50% of the total costs for the conversion process to date).

Downloads (in German)