Highly Accurate Method for Real-Time Active Power Reserve Estimation for Utility-Scale PV Power Plants: Preprint

This paper applies a robust technique for determining the available power reserve from a curtailed utility-scale photovoltaic (PV) power plant. The proposed technique does not require deploying any additional equipment or sensors and is based only on the addition of new control logic to the existing power plant controller. Also, the proposed method is universally applicable to PV plants with any type of smart inverters and PV modules. Accurate determination of available power is important for using curtailed PV generation as a resource for various types of active power controls, such as spinning reserves and primary and secondary frequency control. For PV plants to be able to maintain the desired regulation range, the plant controller must be able to estimate the available aggregate peak power that all the plant's inverters can produce at any point in time and ensure that the control error stays within the tolerance band at all times. In this paper, we explore a highly accurate control method that uses dedicated inverters within the plant as reference units and evaluates the available aggregate peak power for the whole plant under different cloud variability conditions.