Performance Analysis of Droop Control with Virtual Impedance in Parallel Operation of Microgrid in Islanded Mode

The integration of distributed generation in an islanded microgrid presents new challenges of control. Droop control is a widely used control in the hierarchical framework in a microgrid. However, droop control has some limitations which lead to power decoupling and hence the use of a virtual impedance loop. The virtual impedance loop adjusts the resistive nature of MG and improves overall droop control of the microgrid system. This paper presents a performance analysis of droop control along with the addition of virtual impedance in the island mode operation of MG. The comparison of droop control along with virtual impedance is analyzed and four different microgrid scenarios were considered i.e. with and without virtual impedance, Fault in the transmission line, Sudden increase in load and Sudden decrease in load. All these scenarios were simulated in MATLAB/Simulink and the effectiveness of the control strategies was studied.