In solar systems where there is the presence of both AC and DC energy, inverters provide the bridge between the two. Depending on the type, features and application, inverters need to handle different input and output types. They need to monitor what the system “sees” and help control how the system responds, while simultaneously working in both the AC and DC world.
Inverters can be found in one of three categories: grid-tied, grid-tied with battery back-up and off-grid. Each type of inverter has specific duties, and therefore require certain features, to work successfully. High efficiency, low losses and reliability are some of the standard general features for any inverter. Grid-tied inverters will need to include anti-islanding capabilities and monitor the power grid for outages, while off-grid inverters will be concerned with battery charging capabilities. A grid-tied system with battery back-up is essentially a hybrid of these two types; its operation is slightly more complex and it will need to rely on its grid-tied features when connecting to the power grid and use its off-grid features when providing back-up power.
The type of waveforms produced by an inverter can be square wave, modified square wave and sine wave. In selecting an inverter type, it is essential to know the usage and power rating of the electronics. However, it is also important to be aware of the types of electronics that will be powered. More sensitive electronic equipment requires a pure, high quality sine wave, eliminating any distortions or noise. |
