The transition to alternative energy sources has been going on for quite a few years, covering different areas. Despite the attractiveness of the concept of obtaining free energy, in practice it is not easy to implement. There are both technical and financial difficulties. Nevertheless, in the case of small-scale projects, alternative energy supply is justified. For example, a controller for a solar panel allows you to use free power for electrical appliances even at home. This component regulates the operation of the battery, allowing optimal use of the generated charge.
What controller parameters need to be considered?
First of all, one should proceed from the total power and input voltage of the system under which the controller is selected. That is, it is the power of the battery or complex of batteries that must not exceed the product of the system voltage by the value of the output current of the control device. Moreover, the controller for the solar battery is selected based on the calculation of the voltage in the discharged battery. In addition, a 20% margin for voltage should be provided in case of increased solar activity.
Also, the controller is calculated in terms of compliance with the input voltage. This value is strictly regulated for the same cases of abnormal radiation activity. On the market, the controller for the solar battery is presented in different forms, each of which assumes its own specifics for evaluating the described characteristics.
Features of the choice of PWM controllers
The choice of this type of control device is characterized by a simple approach - the future user only needs to determine the optimal short-circuit current in the module used. A certain margin should also be provided. For example, if the current of a 100 W solar generator stably operates at a short-circuit current of 6.7 A, then the controller should have a nominal current value of about 7.5 A.
Sometimes the discharge current is also taken into account. It is especially important to consider it when operating controllers with a load control function. In this case, the choice of controller for the solar battery is made so that the discharge current does not exceed the same nominal value in the control device.
Features of the choice of MPPT controllers
This type of controller is selected according to the power criterion. So, if the maximum current of the device is 50 A and the system operates optimally with a voltage of 48 V, then the peak power of the controller will be about 2900 W, taking into account the addition of the insurance potential. And here another aspect is important. The fact is that the voltage of solar generators can decrease in cases of their discharge. Accordingly, power can fall by a significant percentage. But this does not mean that it is possible to make a discount on the performance of the controller itself - its power potential should cover exactly the limit values.
In addition, in the matter of how to choose a controller for MPPT solar panels, the specific features of the emitted radiation should be taken into account. On the surface of the earth, the intensity of sunlight adds another 20% to the capacity of the battery infrastructure. Such phenomena cannot be called a rule, but even as an accident they should be provided for in calculating the power of the controller.
How to make a controller yourself?
A typical version of a homemade controller involves the use of a modest set of elements. Among them there will be a transistor withstanding current up to 49 A, a relay-regulator from a car, a 120 kฮฉ resistor and a diode element. Next, the relay is connected to the battery, and then the wire passes through the resistor to the gate of the transistor. During the operation of the relay regulator, the positive signal must unlock the shutter, and the current from the sunlight module will pass through the legs of the transistor to the battery.
If you make a universal controller for a solar panel with your own hands, with the expectation of eliminating spontaneous consumption of stored energy, then integration into the diode system will be mandatory. At night, he will create a backlight for the solar panel , eliminating the additional energy consumption of the module.
Is it possible to do without a controller for the solar battery?
Before giving an answer to this question, you need to remember what the function of the controller in the solar module is in general. With it, the owner can autonomously control the process of charging the battery pack due to the energy of light. If there is no controller, then the process of filling with energy can occur up to the moment of electrolyte boiling. That is, it is impossible to do without a means of controlling the interaction of the solar panel and the battery. Another thing is that the controller for the solar battery can be replaced by a voltmeter. If peak values โโof charge and voltage are detected, the user can independently stop the process by turning off the battery pack. This approach, of course, is inconvenient compared to automatic control, but in the case of rare use of the system, it can justify itself.
Conclusion
Today many companies are engaged in the manufacture of solar controllers and other components for such modules. This segment is no longer considered detached and specific. On the market, such components can be purchased for 10-15 thousand rubles, and of good quality. Of course, a home-made controller for a solar battery using budget resistors and parts of automotive electrical equipment will cost several times cheaper, but it can hardly guarantee the proper level of reliability. And the moment of stability and safety is especially important in the operation of solar panels, not to mention the battery. If the solar module is successfully equipped with a high-quality controller, the owner will be able to count on the automatic accumulation of electricity without the need for interference in the generation process.