Solar power system – what inverter should we choose ?
One of the most important element of PV system is an inverter. It is a heart of the system and without it we won’t be able to transfer energy into the grid. Thanks to it we are capable to transform DC current into AC current, but it is not the only function of this device. Modern inverters can be use also as monitoring of PV system, optimizers and power-system protection.
While we are looking for an inverter, we should check:
Size of our inverter should fully depends on total power of our photovoltaic panels.
What is more, power of our inverter and PV panels not always should be the same. For example for central-european conditions, you should choose PV panels with nominal power about 10% lower than the power of PV modules which is caused by lower solar radiation in that area.
Modern devices give us opportunity of constant monitoring and analysing parameters of our system. With those solutions we can for example easily check efficiency of our PV system. What is more, thanks to Wi-fi modules, those devices can inform us about any malfunction remotely.
Maximal Power Point Tracker
MPP Tracker is a device that gives us opportunity to achieve maximal efficiency of PV system. Depends on model of inverter you can get from one to multiple trackers in one device. They are very important where we need to design PV system on a roof with many different areas. With one MPP tracker we should always connect panels with the same azimuth and angle.
Another important feature of modern inverters are protection systems. Almost all modern inverters provide us basic level of power-system protection for example from overvoltages.
Unfortunately different inverters offer us different protection level so we always have to choose protection level that suits our needs.
Different kind of protection is automatic disconnection of PV system in case of blackout. It is very important parameter of inverters because without it we will be unable to safety service the grid.
Anti Potential Induced Degradationa (PID) System
PID is a form of PV panels degradation that caused decreasing efficiency of modules because of stray current which is dangerous for crystalline PV modules, especially those working in hot and high humidity conditions. Best way to stop this process is grounding negative pole which is possible only with inverters that have galvanic isolation.
Like you can see transforming direct current into alternating current is basic, but not the only feature of modern inverters. Because of that when we are going to choose an inverter we should also check other important features of those devices.