A Grid-Friendly Plant: The Role of Utility-Scale Photovoltaic Plants in Grid Stability and Reliability

We have described a utility-scale, grid-friendly PV power plant that incorporates advanced capabilities essential to supporting grid stability and reliability. It includes features such as voltage regulation, active power controls, ramp-rate controls, fault ride through, and frequency control. These capabilities provide the intrinsic benefits of reliable plant operation in the grid, which in turn results in additional plant yield and potential additional revenue. Such capabilities are essential for successful the deployment of largescale PV plants. A key component of such a grid-friendly plant is a plant level controller specifically engineered to regulate real and reactive power output of the solar facility such that it behaves as a single large conventional generator, although within the limits dictated by the intermittent nature of the solar resource. In cases where the plant output is constrained but the plant has additional generation capability, this controller can reduce the impact of cloud passage and increase overall yield. Plant-model validation against measured field data demonstrates that the WECC-proposed model for a solar PV plant is adequately capturing actual plant behavior.