Enhancement of Solar Farm Connectivity with Smart PV Inverter PV STATCOM

Abstract

This paper presents an innovative smart PV inverter control as STATCOM (PV-STATCOM) for obviating the need for a physically connected STATCOM in a distribution network for controlling  steady state voltage  and  temporary over voltages (TOVs)  resulting from unsymmetrical faults.  Two 10 MW PV solar systems are already connected in the distribution feeder of a utility in Ontario, Canada. A STATCOM is installed to prevent the  steady-state voltage and TOV issues  arising from the connection of a third 10 MW PV solar farm  at same bus. It is demonstrated from PSCAD electromagnetic transient studies that if the proposed PV-STATCOM  control is implemented on the incoming third 10 MW PV solar farm, all the above voltage issues are mitigated satisfactorily as required by the utility Grid Code. This proposed smart inverter  PV-STATCOM  control therefore eliminates  the  need for the physical STATCOM, saving an enormous  cost  for  utilities dealing with voltage rise and TOV issues with grid connected PV systems.  Such a control can effectively increase the Distributed Generator hosting capacity of distribution feeders at more than an order of magnitude lower cost under similar network conditions.  Moreover, this novel grid support functionality can open new revenue making opportunities for PV solar farms.