ARDUINO MPPT SOLAR CHARGE CONTROLLER ( Version-3.0)

The voltage output of a solar panel changes depending on several factors like:

Original: “The new restaurant in town has a modern vibe and serves a variety of international cuisines.”

Paraphrased: “The modern-themed new restaurant in the area offers a range of international dishes.” The amount of sunlight. The company’s profits have doubled compared to last year. The load is linked. Rewrite the given text using the same language and ensuring the word count remains the same: 3. Paraphrase the following text using the same input language and keep the same amount of words: The temperature of the solar panel.

Throughout the day and with changing weather conditions, the solar panel will consistently produce varying levels of voltage. For every voltage level, the solar panel will produce a specific current in Amperes. The Amps produced for a certain voltage can be found on the IV curve of a solar panel’s specification sheet, which typically looks similar to the figure-1 displayed above.

The blue line in figure-2 shows a voltage from solar panels of around 30V, paired with a current of about 6.2A. A current of 5A is indicated by a voltage of 35V on the green line.

The relationship between power, voltage, and current is that power is equal to voltage multiplied by current.

In the picture above, while tracing the red curve, you will reach a point where the result of Voltage multiplied by its corresponding Current is greatest compared to any other point on the curve. The solar panel’s Maximum Power Point (MPP) is the term used for this.

What Is MPPT ?

The voltage produced by a solar panel varies according to different factors such as…

1. The level of sunlight 2. The electrical load connected 3. The panel’s temperature.

MPPT is an acronym that stands for Maximum Power Point Tracking. MPPT charge controllers are utilized to maximize power output from PV modules in specific circumstances. To delve deeper into this concept, we must analyze the power curve traits of a solar panel. Refer to the image above, downloaded from the internet, for a visual explanation of MPPT. Thus far, we have observed that the peak power point (MPP) of a solar panel is located at the intersection of the current and voltage curve.

A 12V solar panel may fluctuate between 12V and 21V depending on the connected load and sunlight brightness, due to its internal resistance reacting to varying irradiance levels. Solar panels only operate at their rated power output at a specific voltage and load, which varies with fluctuations in sunlight intensity.

For instance, consider a 100 watt solar panel with a rating of 18V at 5.55 amps.

The Solar panel requires a load of 3.24 ohms, calculated using the 18 V at 5.5 amps rating.

If a different load is connected, the panel will output less than 100 watts. Connecting a static load with a resistance different from the panel’s internal resistance at MPP will result in drawing less power from the panel than its maximum capacity.

Taking a simple example say we connected the above 100W panel directly to a 12V lead acid battery, the panel voltage would be dragged down near to the load voltage of the battery as the batteries resistance is lower than the panels, but the current stays the same at 5.55 amps.This happens because Solar Panels behave like current sources, so the current is determined by the available sunlight.

Now the power (P)= V x I = 12×5.55=66.6W. So the Solar panel is now behaving like a 66 watt panel.

This equates to a loss of 100W-66.6W = 34W ( 33.4%).

This is where MPPT comes into play. MPPT circuits can be based on various switch mode power supply (SMPS) topologies, they generally have a fixed frequency but varying duty cycle. The duty cycle is controlled via an algorithm so as to track the changing MPP.