Grid integration aspects of large solar PV installations: LVRT capability and reactive power/voltage support requirements

Abstract

The current work focuses on two specific issues concerning grid-connected solar PV units, i.e. the fault ride-through capability, also called low voltage ride-through capability, and the voltage support function through reactive power injection during faults. With the first one the PV unit can actually provide some limited grid support, whereas with a defined reactive power characteristic it can give a complete dynamic grid support. These two requirements, already known for wind power generation but new for the PV, have been recently introduced in the German technical guidelines for connection to the MV grid. Scope of the paper is to implement these requirements in a large solar PV plant, modeled in DIgSILENT PowerFactory, in order to understand its operation, and to evaluate its behavior and impact on the grid, in terms of stability and voltage support during grid fault.