Electrical engineering design and grid calculations for wind farms
Wind farm electrical design: concept, route selection and grid calculations for a feed-in solution that can be permitted.
The electrical engineering design of a wind farm requires expertise and a good feel for technical interrelationships. There are many questions and variants, and every decision affects project success. We take on the complete concept and route selection, from the wind farm's internal cabling through grid export to the grid operator's point of feed-in.
To this end, we survey existing installations in detail and carry out modern grid calculations: load flow, short circuit, loss optimisation and thermal sizing. The grid impact shows whether your wind farm is grid-compatible. This produces a technically feasible, grid-optimised solution that can be permitted. We plan SF-6-free, integrate battery storage early and take required substations into account.
What the calculations must deliver is specified by the grid operators through the connection conditions. The load flow shows how power and voltage are distributed in the farm network and at the grid connection point. For the short-circuit calculation, the grid operator provides, on request, foundations such as short-circuit power and operating point. For reactive power, it can specify a control method, such as a fixed cos φ, a characteristic cos φ(P), voltage control Q(U) or fixed reactive power. The reactive power method and the setpoint are to be determined in accordance with the applicable TOR and the grid operator's connection conditions, as are the required reactive power range and possible active power limitations. The plant must stay connected to the grid within defined voltage bands, and non-synchronous plants must be able to support voltage control. In the event of grid faults, non-synchronous plants connected at medium voltage or above must be able to feed in a reactive current of at least the rated current, and after fault clearance, active power should rise again as quickly as technically possible. Reactive power compensation can be required for the line between the plant and the grid connection point. The permissible grid impacts are part of the connection concept, with proof provided by conformity tests and simulations. The plant must be designed to ride through several consecutive grid faults and may disconnect from the grid if its thermal design limits are exceeded in the process. Requirements for dynamic reactive current support, including the gain factor, depend on the plant class, grid level and the applicable connection rules, and separate voltage-time profiles apply for connections below and from 110 kV. Protection settings must not jeopardise fault ride-through capability.
Electrical engineering design affects many other disciplines, such as route selection, construction planning and permitting. We therefore coordinate it closely with our permitting department. Your advantage: risks become visible early, and the grid operator receives traceable planning. The foundation is the grid concept and coordination with the grid operator. The planning is complemented by civil engineering design of the wind farm infrastructure, followed by the detailed design. For PV projects, there is electrical engineering design for PV plants. For projects in Germany, further expert reports are added, such as the air pollution control report.
