Assessment of the Distributed Generation Carrying Capacity in New-Type Distribution Networks Based on Different Load Levels

Currently, the large-scale grid connection of distributed generation, represented by wind electricity and photovoltaics, into distribution networks has become a trend. However, this massive integration can lead to a series of problems including grid frequency and voltage fluctuations, power system instability, equipment failures, power outages or interruptions, and a decline in power quality. This paper presents a way for assessing the carrying capacity of distributed generation under different load levels. Considering various factors influencing the carrying capacity, a comprehensive evaluation method is proposed by utilizing a multi-time scale factor matrix, an improved entropy weight method, and the Analytic Hierarchy Process (AHP) combined with a comprehensive weight way. Based on the thermal stability limit, the maximum DG injection is calculated using the reverse load ratio, and the carrying capacity of the distributed generation system is determined by gradually decreasing it at each voltage level to meet the specified criteria, considering the actual operating conditions and safety boundaries. Finally, through a case study analysis of a distribution network model in Zhejiang province, the carrying capacity of distributed generation in that region is obtained.