off grid solar hybrid inverter Use can be divided
The Types and Main Functions of Off - grid Solar Hybrid Inverter
Off-grid solar hybrid inverter according to the use of grid-connected inverter, off-grid inverter, micro-network energy storage inverter three categories, and grid inverter according to power and use can be divided into micro-inverter , Series inverter, centralized inverter, distributed inverter four categories, micro-inverter, also known as component inverter, power level 180W to 1000W, suitable for small power generation system; Type inverter, power in the 1kW to 5kW single-phase inverter for household power generation system, and network voltage 220V, 5kW to 70kW three-phase inverter for industrial and commercial power generation system, the grid voltage of three Phase 380V.
Grid-connected inverter is a key component to connect the PV array and the power grid. In addition to the DC power that the component sends out into the AC power of the grid, there are the following special functions:
1, the maximum power to track MPPT function
When the sunshine intensity and ambient temperature changes, the PV module input power exhibits a non-linear change, as shown in the figure, the figure shows: PV module is neither a constant voltage source, nor a constant current source, its power with the output voltage Change and change, and load does not matter. Its output current rises with the voltage at the beginning of a horizontal line, reaching a certain power, with the voltage rise and lower, when the component reaches the open circuit voltage, the current drops to zero.
The output power of PV modules is affected by factors such as sunshine intensity and ambient temperature. When the light intensity decreases, the open circuit voltage of the PV module decreases and the short circuit current decreases and the maximum output power decreases. When the PV module temperature drops, the short circuit current decreases, but the open circuit voltage increases and the maximum output power increases ; MPPT function is the maximum power tracking function, by adjusting the DC voltage and output current, so that solar modules always work at the maximum operating point, the output of the same component Current temperature and maximum power under sunshine conditions.
Commonly used maximum power tracking control methods are: constant voltage tracking method (CVT), the PV module terminal voltage fixed at a certain fixed value, characterized by simple control, good stability; power calculation method, current optimization method, perturbation Observation method, incremental conductivity method and other classical control algorithm and the optimal gradient method, fuzzy logic control method, neural network control method and other modern control algorithm.