Closed-Loop Control of Solar PV fed Buck-Boost Converter

Closed-loop control of solar PV fed inverting buck–boost converter regulating 72 V DC output using PI control under irradiance without MPPT

This model implements a closed-loop controlled inverting buck–boost DC–DC converter fed by a solar PV array in MATLAB/Simulink. The objective is to regulate a fixed DC output voltage using feedback control without employing maximum power point tracking (MPPT).

Input (Solar PV Array) : Rated power: 800 W

The PI controller compares the measured output voltage with a 72 V reference and modifies the duty cycle to maintain regulation. Since MPPT is not implemented, the PV operating voltage is allowed to vary depending on load and control action. Due to the buck–boost topology, the output voltage is inverted with respect to the input.Simulation Results

• Mean output voltage: ≈ −71 to −72 V
• Output current: ≈ 1.4–1.5 A
• Output power: ≈ 100–110 W
• Stable closed-loop operation achieved