Implementation of Perturb & Observe MPPT Algorithm for Solar PV System Part2
We will explore the implementation of the Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) algorithm for a solar photovoltaic (PV) system using MATLAB. We’ll delve into the setup, parameters, and testing methodology, as well as how to analyze the results.
Overview of the P&O Algorithm
We discussed the basics of the P&O algorithm. Now, we focus on implementing this algorithm for a solar PV system, specifically using a 250 W PV panel.
Key Specifications of the PV Panel
Maximum Power: 250 W
Open Circuit Voltage: 37.3 V
Maximum Power Point Voltage: 30.7 V
Short Circuit Current: 6.66 A
Maximum Power Point Current: 8.15 A
Setting Up the Simulation
To effectively implement the P&O algorithm, we need to first obtain the I-V characteristics of the chosen PV panel while fixing the cell temperature at 25°C. We then analyze the power outputs under varying radiation conditions (1,000 W/m² to 400 W/m²) to gather necessary data for our algorithm.
Boost Converter Integration
We incorporate a boost converter between the solar panel and the load. This allows us to manage variable loads (5 ohms, 30 ohms, and 100 ohms) to assess the P&O algorithm’s effectiveness under different conditions.
Execution of the P&O Algorithm
Measurement and Input
To execute the P&O algorithm:
Measure the voltage and current from the PV panel.
Use these measurements as inputs to generate a duty cycle that adjusts the converter's output.
The duty cycle is determined by:
Power difference
Voltage difference
These parameters guide the algorithm in maximizing the power extracted from the solar panel.
Program Logic
The algorithm begins by initializing parameters such as the initial duty cycle and defining global variables for voltage, power, and duty cycle from the previous instant. Based on the measured values:
The algorithm checks the power and voltage differences.
Duty cycles are incremented or decremented accordingly to maintain maximum power extraction.
Testing the Algorithm
Variable Load Testing
The system was tested under constant irradiation (1,000 W/m²) while varying the load resistance. The results demonstrated that the P&O algorithm efficiently tracked and extracted the maximum power as the load changed.
Variable Irradiation Testing
Subsequently, the load was fixed while varying the irradiation levels every two seconds. The algorithm successfully adapted to these changes, maintaining effective power extraction across different radiation conditions:
At 1,000 W/m²: Maximum power ~250 W
At 800 W/m²: Maximum power ~200 W
At 600 W/m²: Maximum power ~150 W
At 400 W/m²: Maximum power ~99 W
Conclusion
The implementation of the P&O algorithm in a solar PV system using MATLAB proved effective in tracking maximum power under varying load and irradiation conditions.
Comments