Possibilities of integrating renewable generation to the distribution grid by fault current limiters

Abstract

Over the last decade an evolution towards higher power requirements on distribution networks has to be stated. Due to additional connection of decentralized power generation in terms of renewables, the referred short circuit current (ISC) values for some network segments were steadily increasing. The actual network structure is based on a unidirectional power flow, assuming a centralized power generation. The electricity is transmitted via point-to-point or simple ring structures at the high voltage transmission grid and radial or point-to-point structures in the Medium Voltage Distribution Grid. Medium and low voltage distribution grids are not intended to handle a bi-directional power flow, created by the integration of renewable electricity generation. Tu guarantee a stable operation of the grid, the grid voltage must kept stable the balance between power supply and consumption has to been managed. In consequence the increased short circuit level might push installed equipment to its physical limits. Therefore new technologies like fault current limiters might be one of the solutions. (4 pages)