Simulation of Incremental Conductance MPPT for Solar PV System PART 2

Simulation of Incremental Conductance MPPT for Solar PV System PART 2

Overview of the System

The core of our implementation revolves around a 250-watt solar PV panel. The specifications of the panel include:

• Maximum Power: 250 watts

• Maximum Voltage at Power Point: 30.7 volts

• Maximum Current at Power Point: 8.51 amps

For this experiment, we will fix the temperature at 23°C while varying the irradiation levels. This will help us analyze the performance of the Incremental Conductance MPPT algorithm under different conditions.

Coding the Incremental Conductance Algorithm

The implementation involves writing code to execute the Incremental Conductance algorithm. Here are the key steps:

1. Initialization: Start by initializing various parameters such as the initial duty cycle (42%), maximum and minimum duty cycles (0.85 and 0.01, respectively), and the change in duty cycle (0.05).

2. Measurement: Continuously measure the voltage and current from the PV panel. Utilize global variables to store previous values for comparison.

3. Calculating Changes: Determine changes in voltage and current to adjust the duty cycle accordingly. If the voltage or current changes, update the duty cycle to maximize power extraction.

4. Loop Execution: Implement a loop to keep checking and adjusting the duty cycle until the maximum power point is reached. This loop will help maintain efficiency even with changing environmental conditions.

Simulating Irradiation Variations

In our simulation, we will vary the irradiation levels every two seconds, starting from 1000 W/m² and reducing it to 400 W/m². Here’s how the algorithm performs:

• At 1000 W/m², the algorithm effectively tracks the maximum power at around 250 watts.

• As irradiation changes to 800 W/m², the expected maximum power drops to 200 watts, and the algorithm continues to adjust to track this new value.

• The same pattern follows as we lower the irradiation to 600 W/m² (expected power around 150 watts) and 400 W/m² (expected power around 100 watts), demonstrating the algorithm's responsiveness.

Testing with Load Variations

Next, we will examine how the algorithm performs with varying load resistances while keeping irradiation and temperature constant. We will test the system with three different loads: 5 ohms, 30 ohms, and 60 ohms.

• With a 5-ohm load, the system effectively tracks maximum power at 250 watts.

• After changing the load to 30 ohms, we see variations in power, voltage, and current; however, the Incremental Conductance method continues to extract the maximum power efficiently.

• Finally, when the load changes to 60 ohms, the system again adapts, maintaining effective power extraction despite fluctuations.

Conclusion

Through this implementation of the Incremental Conductance MPPT algorithm, we see its robust performance in tracking maximum power from a solar PV panel under varying irradiation and load conditions. The algorithm successfully adapts to changing environments, demonstrating its effectiveness in optimizing solar energy extraction.