The inverter is considered as the brain of the solar system. And although there are different types of the solar inverters, but they all have the main components, let us see what are they and what are their functions as following:
- Capacitor: It is used to filter ripples on the DC bus originated from semi-conductors switching, keep stable voltage on the DC bus, and reduce losses between the solar array and the solar inverter.
- Monitoring Software: It used to monitor the solar system, providing the status of solar system to installer & owner, and alert them in case of faults. This software is running on inverter internal controller/processor.
- Solid State Devices: Mainly we intend IGBTs, MOSFETs and transistor, they are used to do the inverter main job which is converting DC current to AC current.
- Magnetic components: They include transformer and inductor to filter and smooth the AC wave shape for electrical grid connection, also they provide isolation between the DC circuit and the AC grid.
Solar Inverters Types:
There are mainly 3 types as following;
- Off Grid Inverter, also called stand-alone inverter: It used in isolated system, it just converts batteries DC voltage “charged from solar panels” to AC voltage to feed the load, and it does Not interfere with the electrical grid/utility. It usually incorporates integral battery charger to charge/replenish batteries from AC stand-by source.
- On Grid Inverter, also called grid tie inverter: It used to be connected with the grid, and it automatically shuts down upon grid supply loss for safety, and it does Not work during utility outage.
- Special Battery Backup Inverter: It is connected to batteries, charge/replenish batteries from backup AC supply via onboard charger, and export extra generated electricity to the grid. Also, this inverter is able to feed the load with electricity during utility outage.
- Hybrid Inverter, This inverter is connected to solar array, batteries, and utility grid. It is able to manage all, so it works for stand alone, grid tie and backup application.