Analysis of the behavior of MVDC system in a distributiongrid compared to a UPFC system

Abstract

The increase in electricity demand, the incorporation of renewable energies, orthe trend toward deregulation in the power market, implies significantchanges in the power networks. Load flows are considerably altered, givingrise to technical problems in the system, such as stability limitations or voltagelevel control. In this context, the use of devices based on power electronics tointerconnect distribution grids is presented as an excellent option to help solvethese problems and control load flows and bus voltages. The topology MVDC(Medium Voltage Direct Current) is starting to be considered an option forenhancing transfer capacity and providing increased power quality at distribu-tion grids. However, this technology is still immature and relati vely unknown,for this reason, the main motivation of the article is to help spread the benefitsof integrating this technology in distribution grid and to determine the capabil-ity of the MVDC to control active and reactive power in distribution grid aswell as its behavior in the event of a short-circuit. The main novelty is to ana-lyze the behavior of the MVDC through a case study, based on a real situation,but comparing it with one of the most complete and flexible FACTS devices,Unified Power Flow Controller (UPFC), noting that MVDC technology is abetter option for operation in medium voltage networks, since allows the con-trol of the active and reactive powers independently and in the case of a short-circuit acts on the currents circulating through the electrical line mitigatingthe effect caused by the fault.