In any solar-powered system, a solar charge controller is very important. These controllers regulate the voltage and current coming from the solar panel to the battery. This saves the battery from overcharging. There are mainly 4 basic types of solar charge controllers. Let’s discuss what is MPPT charge controller and how it works.
What is MPPT Charge Controller?
The most basic function of a solar power system is solar panels gathering energy from the sun and storing it in batteries for later use. You cannot, however, simply connect your solar panels to your batteries and expect them to charge. To get the most out of your solar panels, you’ll need a charge controller to efficiently charge your batteries. The maximum power point tracking (MPPT) charge controller is the most efficient sort of charge controller. Let’s discuss in detail what is MPPT charge controller.
What is Maximum Power Point Tracking?
Before we get into how MPPT charge controllers work, it’s important to understand how they got their name. The maximum power point voltage is the voltage at which a solar panel produces the greatest power. The maximum power point voltage changes depending on the surroundings and time of day.
MPPT charge controllers derive their name from the fact that they monitor the solar panel and calculate the maximum power point voltage under current conditions. This is known as maximum power point tracking or MPPT for short.
What Exactly is an MPPT Charger?
The ideal operating voltages of solar panels and batteries differ. Furthermore, their voltages fluctuate. An MPPT charge controller is a DC-DC converter that improves a solar system’s efficiency. This is accomplished by improving the voltage match between the solar panel array and the batteries.
A 12-volt battery, for example, has a nominal voltage that varies depending on the state of charge between slightly over 10 volts and just under 13 volts. In addition, the voltage required to charge a 12-volt battery varies between 13.5 and 14.5 volts depending on the charging phase.
The ideal output voltage of a solar panel, on the other hand, changes based on the panel’s temperature, time of day, cloudiness, and other external parameters. A 250-watt solar panel, for example, may have an optimal working voltage of 32 volts under perfect conditions. If the panel heats up in the sun or on a warm day, the optimum voltage may decrease to as low as 26 volts.
To account for these voltage reductions in the panel and the increased needed battery charging voltage, the rated panel voltage must be greater than the battery voltage. This voltage differential wastes a lot of electricity in the absence of an MPPT charge controller.
Also Read: What is PWM Charge Controller?
How MPPT Works?
When compared to shunt controller and pulse width modulation (PWM) technologies, maximum power point tracking (MPPT) is a more efficient DC-DC converter technique. So let’s see how MPPT works.
Using a non-MPPT charge controller is equivalent to directly connecting the battery to the solar module. A conventional charge controller may charge a battery at the voltage specified by the battery. A fully charged battery has a higher voltage than a depleted battery by definition. As a result, the power drawn by an empty battery is usually less than that drawn by a full battery.
The question arises when we observe a power loss that we are not utilizing while our batteries are running low. What happened to my power? The MPPT makes use of the entire module’s power by controlling the voltage of the battery charging state. The charge controller maintains the voltage and current at optimal levels, allowing the modules to produce the most juice.
Assume we’re utilizing a solar panel with a Vmp of 18.3 volts and an Imp of 11.48 amps. (11.48A x 18.3V= ~210 watts) In general, an empty 12V battery may have 12.2 volts. As a result, the battery would be charged at 11.48A x 12.2V = 140 Watts. That is much less than the module’s highest possible power (210 watts).
An MPPT charge controller raises the voltage and current of the system to as close to the module’s I-V curve as possible. In this scenario, the MPPT charge controller charges the battery at nearly 18.3 V and 11.48A while utilizing the maximum amount of solar panel power. Finally, Maximum Power Point Tracking technology has nothing to do with sun tracking. MPPT is merely a battery charger control feature. After this, let’s explore various MPPT types.
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What are Various MPPT Types?
Maximum Power Point Tracking (MPPT) technologies are used in photovoltaic (PV) systems to continuously maximize PV array output power, which is determined by solar radiation and cell temperature. MPPT types are broadly grouped into two types: conventional methods such as the Perturbation and Observation (P&O) method and the Incremental Conductance (IncCond) method, and Advanced methods such as the fuzzy logic (FL) based MPPT method.
1. Conventional MPPT
Conventional MPPT methods were proposed a long time ago and are therefore quite popular. The key benefits of these are their simplicity and ease of implementation. These algorithms can only track a single MPP under uniform illumination.
Traditional approaches are straightforward, but they cannot distinguish between local and global peaks when partial shading occurs, hence their efficiency is limited.
a. Perturbation and Observation (P&O): The Perturb and Observe algorithm is a variation to the traditional algorithm that limits the algorithm’s search space, lowering complexity and enhancing performance under uniform and variable weather circumstances.
b. Method of conductance (IncCond): The incremental conductance technique is based on the assumption that the slope of the PV array power curve is zero at the MPP, resulting in, with. Given that the MPP can be followed by comparing instantaneous conductance to incremental conductance.
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2. Advanced MPPT
These approaches are often known as soft computing, bio-inspired (BI), or artificial intelligence (AI). They are relatively sophisticated, yet they outperform standard methods in terms of tracking performance.
Because of their increased efficiency, advanced tracking technologies are frequently used. While conventional and advanced methods have limitations, hybrid methods discover a means to overcome these restrictions.
a. Fuzzy logic-based MPPT: The controller is developed to enhance the voltage of the PV module. As the voltage and current across the PV panel changed, the proposed technique used fuzzy logic-based controlled (FLC) to initiate the control command to the output buck-boost converter.
Maximum Power Point Tracking (MPPT) controllers are gaining popularity as an essential PV system improvement topic. These controllers use various algorithms, and their efficiency, performance, modernism, complexity, and tracking speed vary. MPPT controllers have improved rapidly, and they can be broadly classed as conventional or advanced techniques. Choosing the best MPPT approach is still a work in progress. After this, let’s learn about the advantages of MPPT.
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What are the Advantages of MPPT?
The advantages of MPPT are as follows:
1. MPPT chargers actually use nearly all of the available power. In other words, it will take all of the available power from a module and condition the voltage and amperage to the appropriate battery voltage.
2. Several MPPT charge controllers can tolerate far greater voltages than the battery.
3. By connecting numerous modules in series, you can increase the voltage while keeping the current constant.
4. Keep in mind that MPPT chargers have a maximum DC input voltage. The most advanced and therefore the most expensive solution is the MPPT charge controller.
5. Nonetheless, it saves you money on wiring, modules, and racking.
Also Read: 5 Major Advantages of Solar Street Light
What are the Disadvantages of MPPT?
The disadvantages of MPPT are as follows:
1. Maximum Power Point Tracking or MPPT biggest ‘s downside is its high cost. Such a system will typically cost more than a standard, non-tracking charge controller system since the MPPT controller requires more complicated electrical components.
2. The MPPT controller must be put between the solar panel and the batteries, the system will necessitate more wiring.
3. Another drawback to taking this into account is complexity. Installing and configuring an MPPT controller needs more technical expertise than a typical charge controller, which might increase installation costs.
4. MPPT system can be difficult to diagnose if problems emerge.
5. An MPPT system may prevent the batteries from charging completely. This is because the MPPT controller normally only permits the batteries to charge up to 80%-90%, implying that the PV array will be operating near, but not necessarily at, its peak power point (PPP).
Are MPPT Solar Charge Controllers Worth the Investment?
MPPT charge controllers cost more than PWM controllers. With tiny, simple systems, the additional expense of updating your controller may not be worth it. However, in larger systems or in places with inclement weather, the greater power and efficiency gained by using an MPPT controller will likely more than offset the controller’s additional cost.
Nobody enjoys wasting energy. MPPT charge controllers allow you to get the most out of your solar panels without having to worry about changing weather conditions or ensuring that your solar panels are correctly sized to your battery voltage.
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