Design of off-grid photovoltaic power generation system

Off-grid photovoltaic power generation systems are widely used in remote mountain areas, areas without electricity, islands, communication base stations, street lights and other applications. Regardless of day or night, even if there is no grid connection, it can still provide reliable power supply at any time to meet the needs of residents, schools or small factories in areas where there is no electricity, lack of electricity and unstable electricity.

Photovoltaic off-grid power generation system can be divided into small DC system, medium off-grid power generation system and large off-grid power generation system. Small DC system is mainly to solve the most basic lighting and DC power charging needs in areas without power; The medium off-grid system is mainly used to meet the demand of households, schools and small factories. Large off-grid power generation systems mainly address the needs of villages and islands.

The design principle of off-grid photovoltaic power generation system: on the premise of meeting the demand of load electricity, use the least photovoltaic modules and cells to build the system and save the input cost.

1. The design of photovoltaic modules: the peak power of solar modules = (load power (W) * hours of electricity consumption per day * continuous rainy period surplus coefficient) / (system efficiency * local daily average peak sunshine hours)

2. The design of the photovoltaic controller: the control current of the photovoltaic controller = the peak power of the solar cell module / the rated voltage of the battery pack. It should be noted that in high-altitude areas, the photovoltaic controller needs to amplify a certain margin and reduce the capacity.

Note: Margin refers to the difference between the design maximum limit of a certain index of the equipment and the normal operating limit.

3. The design of the off-grid inverter: the capacity of the inverter = (the power of the load (W) * the margin factor required by the inverter) / the power factor of the inverter.

4. Design of lead-acid battery: capacity of the battery pack = (load power (W) * load hours per day * continuous rainy days) / (rated voltage of the battery pack * battery discharge coefficient * inverter effectiveness)

If you need to configure photovoltaic off-grid power generation system, please contact Xindun.