Performance Evaluation of Islanded Mode Voltage and Current Control in DC Microgrid

Abstract

Increasing penetration of renewable energy sources such photovoltaics poses into sources diversification. These sources can act as distributed generation (DG) in the network. Hence the source, short distribution line and loads can be combined and joined as a locally network of Microgrid (MG). As locally network, the network parameters such voltages and currents can be fully designated by the DGs. Without any properly method, the voltage and current in the DC MG can be over the designated limits. On the other hand, the DGs have different current capacities to be generated. To solve these issues, this paper proposes and evaluates the method for both voltage control and current control of the sources (i.e. DGs and central grid) in the DC MG. The performance evaluation is conducted via computer simulation with several conditions and cases such fully supplied by central grid, supplied by DGs (islanded mode) and different cases such equal and unequal DGs capacities. The simulation results indicate that the proposed method is able to maintain the load voltage within acceptable limit during load demands fluctuation. In addition, the generated current by DGs can be also designated according to their capacities by implementation of the proposed method.