Power Quality Improvement for a Microgrid Inverter Based on FOPID

This paper was addressed toward the improvement of power quality (PQ) of a standalone microgrid (MG). This study has been focused on the total harmonic distortion (THD) minimization of the output voltage at point of common coupling (PCC) and voltage regulation for the rapid load changing and with different types of loads. The harmonics are reduced by using triple action controller (TAC). TAC consists of a traditional proportional resonant controller (PR) with selective harmonic compensated (SHC) and a feed-forward current controller of pulse width modulated voltage source inverter (PWM VSI). The voltage regulation is based on the fractional order PID control (FOPID) as secondary control to restore the nominal values of the voltage and frequency after their deviation by the droop control. To meet the study objectives, this technique was optimized using particle swarm optimization algorithm PSO for the optimal parameter selection out of the solution space. This study was compared to the previous work. In terms of output voltage, frequency, response time, and THD, the present results were superior. Furthermore, the proposed system guarantees improved overall system PQ, and dependability under a variety of load circumstances.