The fundamental cause of severe output fluctuations in photovoltaic (PV) power plants is the abrupt change in ground irradiance due to cloud cover. To enhance the accuracy of PV power forecasting under cloud cover conditions, this article proposes a second level power forecasting method for PV power plants based on an improved Pix2PixHD image restoration algorithm. First, the PV plant model is constructed based on the actual layout by applying Newton Raphson method. Second, the data characteristics of PV power output from the inverters are deeply explored to analyze the mapping relationship between PV power and irradiance. A virtual cloud image is constructed to represent the cloud cover (power loss) situation by describing the shape, thickness, and movement direction of the clouds. Subsequently, the virtual cloud images were preprocessed using the Canny edge detector, followed by restoration of the processed defective virtual cloud images using the Improved Pix2PixHD image restoration algorithm. Finally, a high-precision PV power forecasting at second level is achieved based on the linear relationship between PV power, irradiance, and pixel values of the virtual cloud image.

Modern power conversion systems (PCSs) have been evolving for over more than half a century by gradually enhancing their digital computing, communication, memory, and sensing functions. However, it is evident that state-of-the-art PCSs have largely overlooked the enticing potential of fully exploring intelligent and extensive interconnections among PCSs and even with other heterogeneous devices. This oversight can be attributed to the fact that digital control systems in PCSs have been designed exclusively for real-time control due to the limited resources of industry microcontrollers. With the rapid development of industry microcontrollers in terms of computing and communication capabilities, this article therefore introduces a novel Internet of Things (IoT) architecture, specifically tailored for PCS, named as power conversion IoT (PC-IoT). This article systematically introduces the architecture, key technologies, and prospects of PC-IoT. The designed PC-IoT offers flexibility with timely information transfer, forming the foundation for empowering the intelligent next-generation PCS. In pursuit of this objective, a multistep transmission-based method for converter time synchronization is proposed. Subsequently, a sequential transmission protocol is developed, enabling multiple converters to send data without conflicts and with low latency in a predefined order. Furthermore, to alleviate communication burden and enhance the system's scalability, we propose a fast data processing method that can be implemented in resource-constrained microcontrollers by employing multiple small-scale models. Finally, the article provides a promising outlook for future applications within the PC-IoT framework. Through experimental validation, the proposed transmission protocol has demonstrated exceptional results, including node-to-node latencies below 3 ms and effective data processing at resource-constrained microcontrollers.