A Fuzzy Interference System for A Grid-connected Micro-inverter with Phase Control Functions for A Small Solar Power System

This paper discusses a novel implementation Fuzzy Interference System (FIS) controller for a grid-connected solar PV in controlling reactive power into an AC grid network. The inverter used is a flyback type inverter due to its simple control design, stable current injection, reliable and relatively inexpensive equipment. There are two inputs used in this fuzzy controller, namely solar PV voltage and an MPPT reference voltage. Then, the output of this controller is the phase signal to the comparator circuit to produce the PWM signals for switches. A conventional PID controller technique is also presented for comparison. The testing is carried out using MATLAB/SIMULINK. The simulated data show that the FIS controller exhibits satisfactory results. This controller can effectively control the reactive power injection from the solar PV into the AC grid. Besides, it provides a lower harmonics level than the conventional PID controller.