Enhancement of Solar Farm Connectivity With Smart PV Inverter PV-STATCOM

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 PVSTATCOM 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.