The full name of MPPT controller is "Maximum Power Point Tracking" solar controller, which is an upgraded product of traditional solar charging and discharging controllers.
The Maximum Power Point Tracking (MPPT) system is an electrical system that adjusts the working status of electrical modules to enable photovoltaic panels to output more electricity. The system can effectively store the direct current generated by solar panels in batteries, effectively solving the problem of living and industrial electricity in remote areas and tourist areas that cannot be covered by conventional power grids, without generating environmental pollution.
The output power of photovoltaic cells is related to the working voltage of the MPPT controller, and only when operating at the most suitable voltage can its output power have a unique maximum value.
The sunlight intensity is 1000W/㎡, U=24V, I=1A; U=30V, I=0.9A; U=36V, I=0.7A; The maximum output power can be seen at a voltage of 30.
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 0. Therefore, for safety reasons, the peak voltage (Vpp) of solar panels at the factory is approximately 17V, which is set based on the standard ambient temperature of 25 ° C. When the weather is very hot, the peak voltage Vpp of solar panels will drop to around 15V, but in cold weather, the peak voltage Vpp of solar energy can reach 18V.
Now, let's go back and compare the differences between MPPT solar controllers and traditional solar controllers. The traditional solar charging and discharging controller is a bit like a manual transmission. When the engine speed increases, if the gear of the transmission does not increase accordingly, it will inevitably affect the vehicle speed. However, for MPPT solar controllers, the charging parameters are set before leaving the factory, which means that the MPPT controller will track the maximum power point in real-time in the solar panel to maximize its effectiveness. The higher the voltage, the more power can be output through maximum power tracking, thus improving the charging efficiency. In theory, a solar power generation system using an MPPT controller will increase its efficiency by 50% compared to traditional methods. However, according to our actual testing, due to the influence of the surrounding environment and various energy losses, the final efficiency can also be improved by 20% -30%.
In this sense, MPPT solar charge and discharge controllers are bound to eventually replace traditional solar controllers
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 achieve tracking of the maximum power point. The disturbance resistor R and MOSFET are connected in series, and under the condition of stable output voltage, the average current passing through the resistor is changed by changing the duty cycle of the MOSFET, resulting in current disturbance. 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. When the disturbance direction is correct, the output power of the solar photovoltaic panel increases, and the next cycle continues to perturb in the same direction. On the contrary, the disturbance is in the opposite direction. In this way, the disturbance and observation are repeated to make the solar photovoltaic panel output reach the maximum power point.