A Spatiotemporal Interpolation Approach for Distributed PV Power Based on WPT and DTW

The loss of electricity during transmission cannot be ignored, and a large number of power consumers are seeking flexible and affordable distributed generation methods to reduce electricity costs. However, a large number of distributed photovoltaic (PV) connections pose challenges to electric power dispatch and the security of power system. Accurate PV power forecast can solve these problems, which requires a large amount of accurate historical data to build forecast model. This article proposes a spatiotemporal interpolation method to complement historical data of PV sites. Wavelet packet transform (WPT) is applied to decompose original time sequence to stable sequence and fluctuant sequence. To eliminate the fluctuations caused by cloud movement, dynamic time warping (DTW) is used to regularize fluctuant sequences of adjacent PV sites. Finally, through spatial interpolation, a precise historical data can be obtained. The case study shows that under cloudy conditions, proposed interpolation method reduces the NRMSE by 0.51% compared to the direct interpolation algorithm.