Review of Hybrid Characteristic Modeling for Renewable Energy Power Generation Systems
The increasing penetration of renewable energy sources has introduced novel instability phenomena in power grids, such as sustained and repeated low-voltage ride-through events, which existing models fail to analyze or explain. This paper addresses the typical continuous-discrete hybrid characteristics of renewable energy generation systems at both the unit and station levels. It discusses the interwoven discrete multi-mode switching and continuous state evolution during faults, emphasizing the necessity of hybrid models. Four classes of hybrid models are compared, including hybrid automata, hybrid Petri nets, switching models, and piecewise affine models, with their applicable scenarios. For switching models and piecewise affine models, parameter identification methods are proposed, and their applicable scenarios are discussed. To tackle the challenge of aggregating dispersed renewable units with diverse discrete event states, a mechanism-data fusion hybrid model aggregation method is proposed. Future research directions for hybrid characteristic modeling of renewable energy generation systems are outlined. The review highlights that current hybrid models remain in an early stage, and mechanism-data fusion modeling is a promising supplement. Key challenges include balancing model complexity and accuracy, and addressing the contradiction between diverse transient behaviors and model universality.