Distributed photovoltaic medium and long term prediction method and system

The invention discloses a distributed photovoltaic medium and long term prediction method and system, relates to the technical field of photovoltaic output prediction, and solves the problem that existing distributed photovoltaic power prediction cannot realize medium and long term prediction, and the method comprises the following steps: analyzing the influence of various meteorological factors on photovoltaic output, and determining key meteorological factors influencing the photovoltaic output; an XGBoost model is constructed, the XGBoost model is trained according to the historical data of the key meteorological factors and the corresponding photovoltaic output historical data, and an XGBoost prediction model is obtained; key meteorological factor multi-year data are substituted into the XGBoost prediction model, and a photovoltaic output medium and long term prediction result is obtained; and establishing a photovoltaic output medium-and-long-term prediction model based on an XGBoost algorithm, and perfo