What is MPPT solar controller?
What is MPPT solar controller? MPPT is short of Maximum Power Point Tracking, which means maximum power point tracking. The MPPT solar controller is translated as a maximum power point tracking solar controller, which is an upgrade product of the traditional solar charge and discharge controller. The so-called maximum power point tracking means that the controller can detect the power generation voltage of the solar panel in real time and track the highest voltage and current value (VI), so that the system can charge the battery with the highest efficiency. Below we discuss the basic principles, functions, and advantages and development trends of MPPT solar controllers over traditional controllers, respectively.
The power generation system using the MPPT controller is the MPPT system, which is an electrical system that enables photovoltaic panels to output more power by adjusting the working status of electrical modules, and can effectively store the direct current generated by solar panels in batteries. It can effectively solve the life and industrial power consumption in remote areas and tourist areas that cannot be covered by conventional power grids, without causing environmental pollution. The output power of a photovoltaic cell is related to the operating voltage of the MPPT controller. Only at the most suitable voltage will its output power have a unique maximum value. The intensity of sunlight is 1000W / down, U = 24V, I = 1A; U = 30V, I = 0.9A; U = 36V, I = 0.7A; it can be seen that the output power is the largest at 30 voltage.
The principle of MPPT
To charge the battery, the output voltage of the solar panel must be higher than the current voltage of the battery. If the voltage of the solar panel is lower than the voltage of the battery, the output current will be close to zero. Therefore, for the sake of safety, the peak voltage (Vpp) of the solar panel is about 17V when the solar panel is manufactured, which is set according to the standard when the ambient temperature is 25 ° C. When the weather is very hot, the peak voltage Vpp of the solar panel will drop to about 15V, but in cold weather, the peak voltage Vpp of solar energy can reach 18V.
The traditional solar charge / discharge controller is a bit like a manual gearbox. When the engine speed increases, if the gearbox of the gearbox does not increase accordingly, it will inevitably affect the vehicle speed. But for traditional controllers, the charging parameters are set before leaving the factory, that is, the MPPT controller will track the maximum power point in the solar panel in real time to exert the maximum efficiency of the solar panel. The higher the voltage, the more power can be output through the maximum power tracking, thereby improving the charging efficiency. Theoretically, the solar power generation system using MPPT controller will be 50% higher than the traditional efficiency, but according to our actual tests, due to the impact of the surrounding environment and various energy losses, the final efficiency can also be increased by 20% -30% .
In this sense, MPPT solar charge and discharge controllers are bound to eventually replace traditional solar controllers.
Features of MPPT
The main function of the MPPT controller is to detect the DC voltage and output current of the main circuit, calculate the output power of the solar array, and track the maximum power point. The disturbance resistor R and the MOSFET are connected in series. Under the condition that the output voltage is basically stable, the average current through the resistor is changed by changing the duty cycle of the MOSFET, so a current disturbance is generated. At the same time, the output current and voltage of the photovoltaic cell will also change accordingly. By measuring the changes in the output power and voltage of the photovoltaic cell before and after the disturbance, the direction of the disturbance in the next cycle is determined. The cycle continues to perturb in the same direction, and conversely, perturbation in the opposite direction. In this way, the perturbation and observation are repeated to make the solar photovoltaic panel output reach the maximum power point.