An Adaptive Power Ramp Rate Control Method for Photovoltaic Systems

Abstract

Photovoltaic (PV) power fluctuations, caused by fast irradiance changes, because of passing clouds, may pose challenges to the stability and reliability of power systems with high penetration of PV inverters. In this regard, new standards impose power ramp rate control (PRRC) on grid-connected PV systems. Available solutions in the literature lack the capability of fast measurement for power ramp rate and fast dynamics under rapid irradiance changes. This article proposes an adaptive flexible power point tracking-based PRRC strategy to obtain fast dynamics. The proposed algorithm in this article performs an additional measurement in the middle of each computation step to detect rapid irradiance changes and subsequently to measure the power ramp rate quickly. Afterward, the voltage step undergoes adaptive calculations to constrain the power ramp rate to the predefined value. Comparison between simulations of the proposed strategy and conventional solutions reveals the superiority of the proposed algorithm for limiting the ramp rate under the influence of rapid irradiance changes. The results gained on experimental grounds on a 2.5-kW PV system are provided to validate the performance of the proposed PRRC algorithm under various operating conditions.