Today, We'll discuss the structure of hybrid inverter: the difference between DC coupling and AC coupling.
First, let's understand their concepts. We will describe them together this time. In fact, they are different ways to manage photovoltaic direct current:
DC coupling manages DC power from photovoltaic through an inverter, directly charging the battery. If the load requires it, it's inverted into AC power and fed to the load. This structure demonstrates how highly efficient the inverter is and minimizes losses.
AC coupling converts all DC power from photovoltaic into AC power, which is then fed into the grid or used by the load. Alternatively, if the battery needs to be charged, the AC power is inverted again by the inverter to charge the battery. As you can see, when the battery needs to be charged.
It can be seen here that DC coupling inverter have fewer switching cycles than AC coupling inverter, resulting in higher losses and conversion efficiency. Does this mean AC coupling inverter have no advantages? No, rather, each has its own advantages. We further explains:
For typical household IP20 inverter, users naturally want to use photovoltaic power as efficiently as possible and minimize losses. Furthermore, once a battery system is installed, users generally do not retrofit it. Therefore, IP20 and IP54 hybrid inverters both use DC coupling, offering users this low loss structure. Over the long term, this can save users considerable costs.
Current grid connected inverter, as well as IP65 and IP66 hybrid inverter, all use AC coupling. We demonstrates:
The primary function of a grid connected inverter is to sell electricity to the state grid, which uses AC power. Therefore, a grid connected inverter must first convert all DC photovoltaic power to AC. Many users are looking to convert their grid connected systems to off grid or hybrid system, but they want to do so at the lowest possible cost. The AC coupling structure of a grid connected inverter is a significant help. The grid connected inverter only requires a small re-inverter to convert the grid connected inverter's AC power back into DC, thereby storing energy for the battery system.
Furthermore, AC coupling inverter offer another function: they can charge battery systems within a certain voltage range. As is known, IP65 and IP66 hybrid inverters are equipped with a battery system with a specific voltage range, rather than a fixed voltage. This allows users to reserve space for future battery system upgrades. If users later want to upgrade their photovoltaic system to include more solar panels, they only need to replace the larger battery system without having to replace the AC coupling inverter. Therefore, AC coupling inverters are generally used for PV projects that require future upgrades.
Different inverter designs are suitable for different scenarios. Xindun Power is dedicated to providing the most suitable and reliable inverters for home users. Please share your needs with us, and we will be happy to answer your questions.
