Improvement of Voltage Stability of Renewable Energy Sources-Based Microgrid Using ANFIS-Tuned UPFC

The paper proposed an impact strategy to stabilize the reactive power variations in islanded microgrid, which results in the control over voltage instability. The required voltage compensation is achieved by injection of an accurate synchronous voltage supply into the microgrid through the power electronics-based converters. This work is accomplished by using advanced flexible AC transmission (FACTS) device and unified power flow controller (UPFC) connected to the microgrid. This compensation reference is obtained through a synchronous voltage management, avoiding the load frequency control loop. In this paper, the improvement in the voltage stability of power system during the transient period in the integrated renewable energy sources (RES)-based microgrid using the unified power flow controller (UPFC) is investigated. Furthermore, the proportional–integral controller of the control system is tuned by adaptive neuro-fuzzy inference system (ANFIS) technique. The ANFIS-tuned UPFC yields the better control on the bus voltages of the test system. This strategy does not require any hardware modification. This strategy is simulated in MATLAB/Simulink to prove its effectiveness.