Total capacitive reactive power of all inverters due to described phenomena is: (15) Q inv - p a r = 3 · V · I inv - p a r = 6 π · V · ε 0 · ε r · A PV d PV · f · V par where Qinv-par is total capacitive power of all inverters due to parasitic capacitances of PV modules and V is phase voltage.
Depending on power factor set, reactive power generated by inverter changes. Value of inverter reactive power is: (11) Q inv - i = S inv - i · sin φ inv - i where Qinv-i is reactive power of individual inverter, Sinv-i is apparent power of individual inverter, sinφinv-i is sinus of power factor angle of individual inverter.
We can use an inverter for reactive power generation. To deliver reactive power only, the voltage source connected to the main grid through a reactance has to generate a voltage in phase with the grid voltage but with higher amplitude.
For example, if the inverter is fed with a 100 kW DC battery and the inverter has to run with 0.9 power factor, it will produce 90 kW of AC power, and the rest 10 kVAr (assuming 100% efficiency of the inverter) will be the reactive power. Here the 10 KVAr is getting generated from the 100 kW DC power. Did I understand correctly?
If is between 0.9 and 1.1 p.u., the controller operates normally (Normal). If is between 0.5 and 0.9 p.u., the inverter is required to inject both active and reactive power to the grid simultaneously (Sag I). Finally, when is smaller than 0.5 p.u., the inverter should inject only reactive current to the grid (Sag II).
Over 95% of the time a PV inverter is running below its rated output current when converting DC solar power to AC active power. The unused capacity of the inverter can then be put to use to produce reactive power.