⚡ MATLAB Implementation of PV-Fed Flyback Converter with P&O MPPT 🌞
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MATLAB/Simulink implementation of a PV-fed Flyback Converter using the Perturb & Observe (P&O) MPPT algorithm. This model demonstrates how maximum power is efficiently extracted from a solar PV array under varying environmental conditions.
🔋 System Overview
The proposed system consists of a solar PV array, a flyback DC–DC converter, a P&O MPPT controller, and a resistive load.
☀️ PV Array: Two 250 W panels are used with one series and one parallel string.
📊 PV Ratings at STC:
Voltage at MPP: 30.7 V
Current at MPP: 8.11 A
🔄 The PV characteristics (I–V and P–V curves) vary with irradiance and temperature, shifting the peak power point.
To continuously operate the PV array at its maximum power point, an MPPT algorithm is essential.
🧠 Why P&O MPPT?
Although several MPPT techniques are available, this simulation uses the conventional Perturb & Observe (P&O) MPPT algorithm due to its simplicity and reliability.
📈 It monitors PV voltage and current
🔁 Calculates power changes
⚙️ Adjusts the duty cycle of the flyback converter to track maximum power
🔧 Flyback Converter Design
Before simulation, the flyback converter is carefully designed using standard equations:
⚡ Input voltage (PV): 30.7 V
🔌 Output voltage: 36 V
🔋 Rated power: 250 W
⏱️ Switching frequency: 4 kHz
🔄 Transformer (coupled inductor) turns ratio
🧮 Calculations include:
Duty cycle
Output capacitor ripple voltage
Output capacitance
Primary and secondary inductances
Once executed, the MATLAB script provides values of C, Lp, and Ls, which are directly used in the Simulink model.
🖥️ Control Strategy & PWM Generation
🧾 The P&O MPPT block receives PV voltage and current
🔢 It computes power and compares present and previous values
🔄 Based on ΔP and ΔV, the duty cycle is incremented or decremented following four standard P&O rules
🚦 Duty cycle limits (minimum & maximum) are enforced
🎚️ The final duty cycle is fed to a PWM generator, producing gate pulses
⚡ These pulses control the MOSFET of the flyback converter
This loop runs continuously to ensure real-time MPPT operation.
🌤️ Performance Under Varying Irradiance
The irradiance is varied every 0.2 seconds:
🌞 1000 W/m² → 🌥️ 800 W/m² → ⛅ 600 W/m² → 🌫️ 400 W/m²
Observed Results:
At 1000 W/m²:
PV Voltage ≈ 30.7 V
PV Current ≈ 7.9 A
PV Power ≈ 250 W
At 800 W/m²: PV power ≈ 200 W
At 600 W/m²: PV power ≈ 150 W
At 400 W/m²: PV power ≈ 100 W
📉 As irradiance decreases, PV current reduces accordingly, while the MPPT controller continuously adjusts the duty cycle to maintain operation near the maximum power point.
🔁 Maximum Power Transfer Concept
The results clearly validate the maximum power transfer principle:
🔗 Maximum power is delivered when the load resistance is effectively matched with the source resistance.
The flyback converter, controlled by the P&O MPPT, dynamically modifies the load seen by the PV array, ensuring optimal power extraction under all tested conditions.
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