Grid Integration of Utility Scale Photovoltaic (PV) Plants Under the South African Grid Code Using a Modified Generic PV Model in DigSilent

The integration of large scale PV power plantsinto the power system grid at medium voltage (MV) level arerequired to operate like the conventional power plants in termsof controlling the frequency and voltage to ensure gridstability. The paper describes the procedures of Utility scalePV plant modeling and then focuses on implementing staticreactive power control for the PV inverter on the alreadyexisting generic PV model in DigSilent. The model undergoesvarious simulation tests namely fixed reactive power, fixedpower factor and voltage control. The fixed reactive power wasset to ۰.۲۰۳ p.u, the fixed power factor was set to ۰.۹۵ and thevoltage was varied at the point of connection in the continuousvoltage range with a droop constant value of ۸ for voltagecontrol. The results show that the model works as required bythe South African grid code.

Keywords:

Photovoltaic model , DigSilent , South African grid code , Reactive power , Voltage control