EVALUACIÓN TÉCNICO-ECONÓMICA DE LA IMPLEMENTACIÓN DE MICRORREDES PRIORIZANDO LA UTILIZACIÓN DE TECNOLOGÍA EN CORRIENTE CONTINUA

Abstract

This work presents the analysis of an AC low voltage distribution network and theeffects of replacing it by a DC network connected to DC loads. The main focus is thecomparison of system losses and voltage drops in the distribution feeders for both typesof networks. All this, considering steady state analysis.Firstly, the study explains the main characteristics and advantages of a DC distributionnetwork. Then, a technical assessment of the residential system changed to DC isperformed with special care of the load behavior for different load types. Load can be classifiedin three different types: resistive, rotatives and electronics. Furthermore, the studyanalyzes the different options for voltage levels, using information from previous studies.Finally, an economic analysis is performed. This considers the investments and savingsfrom electric losses, providing appropriate economic indices for short and long term profit.The different cases analyzed consider the fully replacement of the AC distributionnetwork for a DC system feeding DC loads, besides the voltage selection analysis. Additionally,an hybrid AC-DC system is studied, that is, supplying DC power to some loadsand AC power to others. Load flow simulations are performed in DIgSILENT PowerFactory,which solves the system equations by Newton-Raphson method to obtain the powerflow results.Results show that by fully replacing the original network for a monopolar link DCsystem (380 Vdc) with 100% of DC loads, system losses decrease by 14.58 %, which isequivalent to an estimated saving of 2000kWh per year. Total energy losses for bothapproaches turns out to be less than 2% of the total consumed energy per year. Furthermore,by using the DC network, current increases because of the monopolar configurationin comparison to the original three-phase system. Finally, the DC network also providesthe least voltage drops due to the resistive effect alone in the distribution feeders. Froman economic point of view, the investment turns out to be profitable with return of capitalafter the sixth year in operation.