Netzkoppelte

Netzkoppelte is a term used in electrical engineering to describe systems, devices, or components that are connected to an electrical power grid and interact with it by exchanging energy. In practice, it denotes grid-connected operation, whether for generation, storage, or controlled loads, rather than off-grid or autonomous operation.

The concept covers a range of technologies, including grid-connected photovoltaic inverters, small- and medium-scale wind turbines, battery storage systems that feed power to the grid, and charging stations for electric vehicles. It also encompasses microgrids that operate in grid-connected mode, drawing from or supplying the public network as needed.

Technically, netzkoppelte systems must synchronize with the grid in terms of voltage, frequency, and phase, and comply with interconnection standards and grid codes. Typical requirements include anti-islanding protection, safe shut-down during grid faults, voltage and frequency ride-through capabilities, and the ability to provide ancillary services such as reactive power support or frequency regulation. Standards and regulations vary by region and may include IEEE 1547, IEC 62109, VDE-AR-N 4105 (Germany), or various national certifications.

Advantages of grid-connected systems include expanded renewable energy integration, improved overall efficiency, and access to grid services that can balance supply and demand. Challenges involve ensuring reliability during disturbances, achieving interoperability among devices from different manufacturers, protecting grid security, and maintaining robust control and communications networks.

See also: grid-tied systems, grid codes, anti-islanding, interconnection standards.