Grid connection concept for wind farms: grid enquiry and connection
Grid connection concept for wind farms: we plan the grid enquiry and connection and coordinate the technical details with the grid operator.
A successful grid connection starts with a well-thought-out concept. We take over the complete grid planning, from the feasibility analysis through the grid enquiry to technical coordination with the grid operator. As a result, you receive a viable grid concept that brings your project to the grid reliably and in compliance with the rules. It defines how the wind farm is electrically connected and what connection options exist.
In Austria, the technical and organisational rules (TOR) form the framework for the grid connection of power generation plants. They are divided into several parts, covering, among other things, distribution grid connection, grid perturbations and power generation plants. For large plants, the process follows a fixed logic: grid connection application with technical documents such as single-line diagram, rated current, short-circuit current contribution and protection concept, followed by connection concept, grid connection agreement and operating permit. The grid operator determines the grid connection point, taking into account grid conditions and short-circuit power. The permissible grid perturbations are also part of the connection concept; for harmonics and voltage quality, the TOR name the measurement standards OVE EN 61000-4-7 and OVE EN 61000-4-30.
Plants from 50 MW maximum capacity or with a connection from 110 kV fall under the highest requirement level, type D, with requirements on reactive power, voltage control and fault ride-through. The maximum capacity is decisive, and the grid-effective capacity at the grid connection point must be observed in the grid connection agreement. Several units of the same grid user at a common connection point count as one plant. Significant changes, such as the renewal, reinforcement or addition of plant parts, trigger the requirements for the modified units again. The grid user demonstrates conformity through tests and simulations, and it is monitored continuously. We clarify which requirements apply in the individual case together with the grid operator already in the design phase. Where battery storage is added, it must meet both the requirements for drawing from the grid and those for feed-in. The requirements apply to new or significantly modified power generation plants on transmission and distribution grids.
The planning extends from the internal cabling via the grid export line to the feed-in point of the grid operator. It is SF6-free. This fits the development in switchgear: under the EU regulation on fluorinated greenhouse gases, new medium-voltage switchgear up to 24 kV from 2026 and above 24 kV up to 52 kV from 2030 may no longer contain F-gases, subject to exceptions and transitional arrangements. Calculations for load flow, short circuit, loss optimisation and thermal dimensioning as well as the assessment of grid compatibility based on grid perturbations secure the concept. We plan battery storage and the substations required for it in early. Upstream, the load profile analysis for wind turbines clarifies the grid connection capacity. In the permitting procedure, the electrical design incl. grid calculations for wind farms follows. For PV there is the grid concept for PV plants, for storage the grid concept for battery storage.
