The extra-high voltage network includes generating facilities, such as large wind parks, large conventional power plants, industrial parks and some particularly large power consumers, e.g. Aluminum hut as well as the distribution networks. The current rules for the grid connection of such systems are more than 10 years old and do not meet the requirements of the energy conversion. The Forum Network Technology / Network Operator in the VDE (FNN) has now presented new connection rules for this voltage level.
"This is the first time that uniform requirements for all types of customer systems exist at the highest voltage: generators and consumers, as well as storage and mixing plants. The new application also implements the relevant European Network Codes (RfG, DCC) for this voltage level in Germany and thus facilitates the work of network and plant operators as well as manufacturers, "says Heike Kerber, VDE|FNN.
New features include uniform requirements for offshore wind parks which are connected directly to the existing extra-high voltage three-phase system. This is the case with the wind parks planned in the Baltic Sea. For the wind parks in the North Sea, which are connected by extra-high voltage DC transmission because of the greater distances, VDE|FNN is working on a further separate connection rule, which is scheduled for the end of 2017.
Important innovations are:
- In the future, generating plants must react faster to an increase or decrease in the grid frequency by adapting their output. The mains frequency increases or decreases inadmissibly if production and consumption are significantly imbalanced.
- Uniform and European requirements for the passage of network errors
- For the first time, the detection methods for the maximum voltage are uniformly regulated. As a rule, an individual verification procedure is used for conventional power plants and an installation certificate is used for customer installations from serial production (for example, wind power plants).
The "Maximum Connection Technical Voltage" is the last of four connection rules to implement the European Network Code "Requirements for Generators" (RfG) for Germany. The next step is to deal with the proposed amendments received by 01 October 2017.
This application is part of the activities of VDE|FNN, which ensure safe system operation at all times with increasing consumption of electricity from renewable energies. The design is available through the VDE|FNN website. Proposals for amendments may be submitted by 01 October 2017.