The increasing demand for renewable energies and the growing number of electric vehicles pose major challenges for the electricity distribution grid. In Germany, for example, according to the Renewable Energy Sources Act (EEG) 2023 and the current coalition agreement, the share of renewable energy is to be increased to at least 80 per cent by 2030. However, the current figure stands at just 56 per cent.

As in many other countries around the world, a massive increase in installed wind power capacity and a multiplication of installed photovoltaic capacity will be required in the future. In addition, the expansion of heat pumps is also being strongly promoted in many countries. The reason for this is the worldwide transition from fossil fuels to renewable energy sources. In Germany, for example, heating systems in new buildings will have to be powered by at least 65 per cent renewable energy from 1 January 2024. Another important point is e-mobility: the worldwide number of electric vehicles is to be increased by a factor of 12 by 2030.

The specific challenges for distribution grid operators are highlighted using the example of the large German distribution grid operator Netze BW. The medium and low-voltage grid is often not sufficiently monitored, which can lead to bottlenecks. Secondary substations are mostly not remotely switchable, which makes it difficult or impossible to react quickly to grid problems.

Digital secondary substations (DSS) are becoming a key element for distribution system operators (DSO) in terms of automation, monitoring, and efficient operations of their networks. The DSS will be a vital element of the future actively operated smart grid and thus DSOs as well as manufacturers will have to face new challenges such as large-scale roll-outs of networked devices distributed over the whole power grid.

Compared to classical offline devices, connected devices demand more attention in terms of the associated management and operation processes. For example, a continuous patch management over thousands of devices needs to be realized for maintaining proper IT security standards and for providing functional updates. Manual processes cannot cope with the related huge amounts of tasks in an acceptable amount of time and in an economic way.

Netze BW has therefore defined a new management and operations architecture together with a standardized device for ring main units (RMU), the process interface and detection unit (PIDU).

When used as a PIDU in the digital secondary substation, our new EOR-3DS fault indicator combines classic earth fault and short-circuit location with the necessary digital interface functions. This turns the short-circuit and earth-fault indicator into a completely new class of device: the EOR-3DS as digitisation unit for secondary substations.

Find out more about the EOR-3DS in the application at Netze BW here:

Quick Q&A With Gerald Jacob

(Product Manager »EORSys«)

At the official opening of the standardised digital secondary substation at Netze BW

Digital secondary substations with earth fault and short-circuit indicators can revolutionise grid monitoring and controlling. They offer a way to operate the power grid more efficiently and reliably.