Multiple converter grid connections, network operations and controls involve a wide range of time scales that lead to many types of dynamics and stability problems. Simulations are often used to research these problems. However, the simulation capabilities and adaptability depend on the model fineness. Therefore, simulations should consider the time scales covered or reflected the physical processes or phenomenon to be studied to select the appropriate fineness model. This paper summarizes the research, applications and development trends of power grid simulations with multiple converters. The common characteristics of converter networking and control are analyzed for one system with a conventional multi-level voltage source converter (VSC) and one system with a modular multi-level converter (MMC) as examples. The response time characteristics of the main circuit and the control links are analyzed to determine the multiple time scale dynamics and time scale divisions of the converter networking. This paper analyzes the matching between the converter model fineness, the simulation requirements and the time scale of the dominant physical process. Simulations show the adaptability of four common fineness converter models, their applications to power systems, and the accuracy of the converter networking time scale analysis. The results also show adaptability of various fineness models and simulations.