Power flow analysis of meshed AC-DC super grid

Abstract

The unbundling of power market and continuousincrease of renewable generation over the years has resulted inbulk power transmission over long distances and cross-borderlinks. Moreover, Integration of renewable generation is set toincrease every year to fulfill EU's vision and other countryspecific goals. These require an expansion of existingconventional AC transmission network to hybrid/meshed ACDC.In this regard, several point to point projects all aroundEurope have been planned, some of which are already up andrunning. Next step towards this is the building of multi-terminalHVDC grids. The construction of multi-terminal DC (MTDC)leads to major changes in the power flow of the existing grids.This paper investigates such meshed AC-DC grids and attemptsto predict the behavior of the future grids via load flow studies.To facilitate the power flow and easier flow control, a new type ofinterface node for the converter nodes has been proposed whichhas been tested on a small test system. Finally, power flowanalysis has been done on a simplified model of North-WesternEuropean grid connected to Great Britain grid and Nordic gridvia DC interconnections for several scenarios in future (until2030). It's noteworthy to mention that in the test models(analyzed scenarios), all the planned HVDC links and North SeaTransnational Grid (NSTG) project have been includeddepending on their estimated date of completion. A MATLABbased tool has been developed to run power flows with varyingwind, load and conventional generation inputs. The results arepresented by times series plots of essential result variables suchas voltages, branch loadings etc.

Date of Award	31 Aug 2014
Original language	English
Supervisor	M. Gibescu (Supervisor 1)