Synchronous Generator Control Concept and Modified Droop for Frequency and Voltage Stability of Microgrid Including Inverter-Based DGs

Abstract

Microgrids have gained much attention in recent years. The main challenge of this system is controlling the voltage and frequency in islanded mode. The inverter-based distributed generators (DGs) have low inertial property and in load change, the microgrid frequency and voltage are easily violated. Using the synchronous generator (SG) control concept, the inertial property of SG results in more stability of frequency and voltage in microgrid. In other hand, droop method is the basic idea of control in islanded mode. However, the simple or modified droop method cannot guarantee returning the main parameters to the reference values when they are violated. Thus, combining the control concept of SG and also modified droop method can enhance the voltage and frequency stability and ensure returning the violated values to the reference ones. The main goal of this paper is proposing this combinational control while simulation results show that using the proposed control strategy, the stability of frequency and voltage is improved even in sudden and different load changes compared with other efficient works in this filed. Moreover, without control strategy, the instability in frequency and voltage may be undesirable in the proposed system as discussed in the paper.