SWOT analysis of an extended reactive power range of PV-inverters serving smart electricity grids

There is a high and increasing PV-penetration in Germany leading also to strong impacts on the distribution grids those systems are connected to. Therefore grid codes and standards were defined requiring the PV power electronics interfacing to the grid to alleviate negative impacts by reactive power provision (besides other measures). Current standards define a rather small fraction of reactive-power provision proportional to the active power feed-in. This paper discusses the pros and cons of extending the range of reactive power provision. On the one hand it unveils new opportunities for enhanced “grid-friendly” operation together with a sensitivity analysis; on the other hand it shows necessary developments on the power electronics side. Since in general inverters may also support grid operation during times of no PV feed-in, they can also alleviate impacts caused by other components such as charging stations for electric vehicles on grid voltage. This paper shows that under voltages due to high electric vehicle penetration can be solved by an extended reactive power range of PV-inverters