Use of capability curves for the analysis of reactive power compensation in solar farms

Generation capability curves have been used for the design and operation of conventional, nonrenewable - type power stations. The maximum generating capacity of a station is given by the aggregate of the capability curve for each generator. In the case of a solar farm, however, the generating capacity cannot be obtained by the aggregation of the capability curve for each inverter due to the presence of impedances in the collector system, in the substation and in the export transmission line. It is convenient to determine the generating capacity of a solar farm by incorporating these impedances into a capability curve to indicate the maximum active and reactive power at the point of interconnection with the transmission system. This paper describes the steps required to determine the capability curve of a solar farm and enumerates the factors affecting the shape of this curve.