A PV inverter or solar inverter converts a variable DC voltage generated by a photovoltaic (PV) solar panel into a mains frequency alternating current (AC) inverter that can be fed back to a commercial transmission system or supplied The grid's grid is used. Photovoltaic inverters are one of the important system balances (BOS) in photovoltaic array systems and can be used with general AC-powered equipment. Solar inverters have special features that work with PV arrays, such as maximum power point tracking and islanding protection.
Solar inverters can be divided into the following three categories:
1. Stand-alone inverters: used in independent systems, the PV array charges the battery, and the inverter uses the DC voltage of the battery as the energy source. Many stand-alone inverters also incorporate a battery charger that can be used to charge the battery with an AC power source. Generally, such an inverter does not come into contact with the power grid, and therefore does not require an islanding protection function.
2. Grid-tie inverters: The output voltage of the inverter can be sent back to the commercial AC power supply, so the output sine wave needs to be the same as the phase, frequency and voltage of the power supply. The grid-connected inverter will have a safe design. If it is not connected to the power supply, it will automatically turn off the output. If the grid power supply is powered off, the grid-connected inverter does not have the function of storing power.
3. Battery backup inverters are special inverters. The battery is used as the power source. The battery charger is used to charge the battery. If there is too much power, it will be recharged to the AC power supply. end. This type of inverter can provide AC power to a specified load when the power grid is powered off, so it needs to have an islanding protection function.