Network parallel operation
Network parallel operation refers to the operation of energy sources connected in parallel to the electricity network . These are mostly small, decentralized sources such as wind turbines , solar power systems or combined heat and power plants . The energy obtained there is not fed into an island network , but into the network. Due to the Renewable Energy Sources Act and the Combined Heat and Power Act , network operators in Germany are obliged to purchase this energy.
The voltage and frequency of the fed-in energy is specified by the network. In the European network, the network frequency is 50 Hz and the voltage for the low-voltage network is 230 V / 400 V. Small solar and CHP systems feed into the low-voltage network. Wind power plants and larger CHPs as well as biogas plants are connected to the medium-voltage network and large wind parks also feed in at the high-voltage level .
A permit must be available for the feed-in and the technical regulations of the respective network operator must be observed. An inverter or converter is used on the feed-in side, but also asynchronous and synchronous generators . In Germany, a device for network monitoring with assigned switching devices (ENS) is required for small feeders , as a substitute a separating point that is accessible to the utility at any time. This should z. B. prevent isolated grid operation in the event of planned grid shutdowns , which could endanger the maintenance team.
literature
- Siegfried Heier : Wind power plants, system design, grid integration and control. 4th edition, BG Teubner, Stuttgart, 2005, ISBN 3-519-36171-X