In the optical storage industry, inverters are mainly divided into photovoltaic inverters, off-grid inverters, grid-connected inverters, and hybrid inverters. Power Conversion System (PCS, also known as energy storage converter, two-way converter, etc.) is often seen in industrial and commercial energy storage systems. It should be noted that because the inverter is more of a customary address, so the name of these common inverters in the industry is not completely unified, the same function of the inverter in different brands may have different names. This classification is designed to facilitate understanding of the common types of inverters in the photovoltaic energy storage industry. When choosing an inverter, it is necessary to understand the specific functions and parameters according to the product parameter table or manual, rather than just look at the name.

Photovoltaic inverter, that is, an inverter connected to photovoltaic modules, converts the direct current generated by solar panels into alternating current, which is used by loads or transmitted to the power grid. It needs to be clear that the photovoltaic inverter itself is also divided into off-grid and grid-connected two types, off-grid photovoltaic inverter can only change the direct current of the solar panel to AC power for load use; Grid-connected photovoltaic inverters can not only supply load, but also transmit excess electricity to the power grid (grid-connected photovoltaic inverters have a microprocessor that can sense the AC waveform of the power grid and generate voltage according to the waveform back to the power grid).

The single photovoltaic power generation system has great disadvantages. The whole system can only operate in the daytime under good sunlight conditions, with great restrictions and low utilization rate. To solve this problem, people have come up with energy storage, in which excess power is stored in a medium for use when needed.

Compared with the single photovoltaic power generation system, the energy storage system has the link of energy storage battery, so the DC electricity emitted by the photovoltaic can be partly supplied to the load and partly stored in the battery. When the photovoltaic does not produce electricity, the energy in the energy storage battery can continue to supply the load; Compared with the photovoltaic inverter, the energy storage inverter also needs more than two functions, one is to convert the DC emitted by the photovoltaic into the DC of the energy storage battery, that is, the DC transform, the other is to manage the charge and discharge of the energy storage battery, intelligent switch between photovoltaic and battery or photovoltaic and battery power supply at the same time - this is the off-grid inverter;

In addition, the grid area, insufficient in photovoltaic power generation, should also can use the auxiliary power supply grid, photovoltaic power generation or after supply load and store the remaining, can input power grid, or can use the grid to energy storage battery (such as electricity fluctuation area, can at low electric charge with power grid, the high electricity use batteries). This requires that the inverter can send current to the grid, can perform AC (power grid) to DC (battery charging) conversion and can intelligently switch between various modes - this is the grid-connected inverter.

And the mixed inverter (Hybrid inverter, also known as the energy storage inverter), means the front of All inverter function in one and after more optimization design, has more functions of the inverter, so some enterprises also call it an all-in-one inverter or inverter (All-in-One inverter).