中文说明：
实现光伏预测，通过当天的光伏出力和天气指数加上预测日的天气指数预测明天的光伏出力，基于BP神经网络对光伏出力进行预测。
English Description：
Photovoltaic prediction is realized. The photovoltaic output of tomorrow is predicted by the photovoltaic output and weather index of the day plus the weather index of the forecast day, and the photovoltaic output is predicted based on BP neural network.