Enhanced Maximum Power Point Tracking Scheme for Photovoltaic System Using Fuzzy Logic

This paper solves a ripple problem that is occurred in the photovoltaic power extraction. This last is generated through the direct application of the Maximum Power Point Tracking (MPPT) algorithm, which is used for the voltage regulation of a solar system. This last one includes a KC200GT panel, a resistive load and a DC-DC boost converter. The switch of last one is controlled through finding an optimal duty cycle control, regardless of a sudden change in the solar irradiance and the absolute temperature. It can be provided by the two following separate stages. First, the Fuzzy Logic Controller (FLC) must prior generate an optimal reference voltage according to the existing PV voltage and PV power. The resulting reference voltage is then compared by a measured PV voltage, in which a voltage discrepancy is generated at each sampling time. In second stage, a voltage Proportional-Integral-Derivative (PID) controller is implemented as an extra block in the inner control loop to mitigate the preceding voltage error, generating an optimal duty cycle increment. It is used to automatically update the old duty cycle control. The resulting updated control is then converted to an actual control signal using the Pulse Width Modulation (PWM) generator for real-time converter control. Performance assessments of the proposed FLC-PID-MPPT controller are carried out through comparing its performances with those provided by the standard FLC-MPPT where the given simulation results prove the superiority of the proposed control strategy in terms of tracking accuracy, response speed, and solving the existing ripple problem.